# Class D vs. Class A/B - My Side by Side Comparison



## CPPTG (Feb 22, 2011)

I've been interested in the Class D full range amps for a while. I've wondered what they sounded like, knowing that there are a couple of issues that hinder their performance somewhat, when it comes to full range.

I recently found a good deal on an older Class D full range, so I decided to pick it up so I could compare for myself. I believe its a least a couple of years old so I'm sure a more recent design would perform differently.

I'm deciding not to mention brands or models here as I think its irrelevant for my comparison and I have no desire to bash anyone's amps. I am a firm believer in personal preferences, and what sounds good to me may not sound good to you. I will give the specs of each and say that they are both quality amps, not some off brand run-of-the-mill stuff.

The class A/B I decided to use is something I have in my personal collection. It's a modest 22.5w x 2 channels. I will say however that this amp is known to be somewhat underrated. The Class D is rated at 70w x 4 channels. I used only 2 of the channels in my comparison, of course. I used the same power supply and set of speakers. My test speakers are a couple of home audio, 8 ohm, 5.25" with 3/4" tweeter.

I listened to the Class A/B first, for about fifteen minutes. I just happened to have a copy of Eric Clapton's Unplugged in my test CD player (an old Kenwood that probably puts out about 1 or 2v) so that's what I used. I skipped around to several different tracks.

I switched over the the Class D about as fast as I could, only a couple of minutes. I listened to the same tracks, also for about 15 minutes. I also need to note that I had gains on both amps set to minimal, and had the internal crossover defeated on the Class D, since the A/B does not have a crossover.

The very first thing that I noticed was the difference in output. With the volume on the CD player set exactly the same, the output on the Class D was much less. The 22.5w A/B seemed to be about 30% louder over the 70w D. I am by no means an expert, but this was surprising to me.

The next thing I noticed was a different sound. The A/B sounded fuller and more warm. The D was somewhat hollow and tinny, for lack of a better word. Please keep in mind that even though the difference to me was obvious, it was also on my test bench, not in a car, and not driving down the road. However, I believe I would notice the difference regardless. 

I much preferred the sound of the A/B to that of the D, no question. I'm an old school guy who was big into car audio in the late 80's and 90's. I grew up with some great amps. Do I think that Class D has a future? Sure. There are some very nice features on the amp, especially the built in crossovers. Will I be running one in my next system? No. For me, the quality of sound just isn't there. 

I just wanted to post my findings and opinions and see if anyone else has compared the two and what the outcome was. Again, this was a quick side by side test, on a bench, not in a car.

Just my 2 cents.


----------



## t3sn4f2 (Jan 3, 2007)

NwAvGuy: What We Hear


----------



## CPPTG (Feb 22, 2011)

t3sn4f2 said:


> NwAvGuy: What We Hear


LOL. I hardly had time to post my comments before this reply.

I'm willing to accept the fact that there may be some bias. And no, of course my test was not "blind". 

I do however feel that the difference was enough for me to be able to choose one over the other. Again, just my opinion, I'm sure some will agree and some will disagree.:laugh:


----------



## Richv72 (May 11, 2012)

Nice review man, I have also been wanting to do a comparison between old school class a and new class d.


----------



## thomasluke (Jun 10, 2011)

Thanks for your time and efforts first. But There are several flaws to your testing. 
1) Even though both gains were set at the minimum there is still a difference in the gain structure of the amps. So yes one was louder but not because of the class.
2) Sounds like you already had your mind made up to begin with. 
3) I could go on but i'm not. See the first reply.


----------



## CPPTG (Feb 22, 2011)

thomasluke said:


> Thanks for your time and efforts first. But There are several flaws to your testing.
> 1) Even though both gains were set at the minimum there is still a difference in the gain structure of the amps. So yes one was louder but not because of the class.
> 2) Sounds like you already had your mind made up to begin with.
> 3) I could go on but i'm not. See the first reply.


Well, I would have much more appreciated your opinion on the subject rather than telling me how wrong I am or that I already had my mind made up. Sure I did, that's why I did the test. 

Oh well, I'm not at all surprised.


----------



## Richv72 (May 11, 2012)

Ive noticed alot of old school amps make their power at 4 ohms and sometimes 2 ohms, alot of the newer class d amps need to be ran at super low ohm loads to put out rated power. Plus the old amps rated their output with lower distortion then the new amps. It was common to see amps rated at .05% or lower distortion not sure what they would measure at 1% distortion like most of the new amps are rated at.


----------



## CPPTG (Feb 22, 2011)

Richv72 said:


> Ive noticed alot of old school amps make their power at 4 ohms and sometimes 2 ohms, alot of the newer class d amps need to be ran at super low ohm loads to put out rated power. Plus the old amps rated their output with lower distortion then the new amps. It was common to see amps rated at .05% or lower distortion not sure what they would measure at 1% distortion like most of the new amps are rated at.


Very good points Rich. This particular Class D rates minimum load at 2 ohms per channel. 4 ohms, rated power it specs at .05% THD. Thanks for bringing that up. I certainly agree with your point about how the new amps are rated. If you look at the CEA ratings like amps give today, it can be quite comical.


----------



## [email protected] (Jun 12, 2008)

Whats a older class D amp? How old? They have made huge advancements in the past few years with them. I would agree with the loudness part, you cant just turn the gain all the way down for both and think they are the same. A better approach would have been to measure the output voltage from both and match that.


----------



## ATOMICTECH62 (Jan 24, 2009)

The punch 45 is a well made amp.


----------



## HIS4 (Oct 6, 2005)

BeatsDownLow said:


> Whats a older class D amp? How old? They have made huge advancements in the past few years with them. I would agree with the loudness part, you cant just turn the gain all the way down for both and think they are the same. A better approach would have been to measure the output voltage from both and match that.


Agree that you should have level matched the amps then did your test. The louder one will always sound better so this eliminates that bias.


----------



## NucFusion (Nov 28, 2010)

I've had many class a/b amps over the years and now I'm currently running the jl audio xd's and I don't notice any differences tht make me want to get rid of the amp. Listening to tracks that I am very familiar with and have heard on 3 different cars, all with different equipment as well as my home audio system that runs off an a/b rotel amp, I honestly can't tell any difference.

With that said, I am going to install my old rockford fosgate punch 40I and 60ix dsm amps and try a listening comparison to figure out which amp I want to use on my tweeters since I'm going active.


----------



## thomasluke (Jun 10, 2011)

CPPTG said:


> Well, I would have much more appreciated your opinion on the subject rather than telling me how wrong I am or that I already had my mind made up. Sure I did, that's why I did the test.
> 
> Oh well, I'm not at all surprised.


Telling you how wrong you are was kinda the point of my post. 
If you would like to know my thoughts as well as many others on the classd vs a/b comparison then you should start here.
http://www.diymobileaudio.com/forum...amplification-can-sound-just-good-true-b.html


----------



## CPPTG (Feb 22, 2011)

I will certainly put a meter on it as soon as I get it back on the bench.


----------



## Sound Suggestions (Dec 5, 2010)

Here we go again! LOL....don't you know all amps sound the same!...of course I'm kidding, I hear you and support you on this one...but wait for it...they are coming...be scared really really scared


----------



## Hanatsu (Nov 9, 2010)

We cannot make assumptions that all class D amps are the same and that all A/B amps are the same. This test is an amp vs another amp test. To make comprehensive tests to support that all class D amps sound different from A-A/B you would have to test a variety of amps of both types and confirm the difference in a double ABX blind test.

Switching/PWM amps are the future, efficiency should be a requirement in car audio imo.


----------



## CPPTG (Feb 22, 2011)

thomasluke said:


> Telling you how wrong you are was kinda the point of my post.
> If you would like to know my thoughts as well as many others on the classd vs a/b comparison then you should start here.
> http://www.diymobileaudio.com/forum...amplification-can-sound-just-good-true-b.html


Why thank you Dr. Amp! I have read the thread. Since you are projecting a know it all attitude, I could really care less what you think. If you read my review, I state its my test and my comparison. Its what I found and my opinion. I didnt mention any brands and am not attacking Class D. Hard to post on this site without the attacks. Oh well.


----------



## CPPTG (Feb 22, 2011)

Sound Suggestions said:


> Here we go again! LOL....don't you know all amps sound the same!...of course I'm kidding, I hear you and support you on this one...but wait for it...they are coming...be scared really really scared


Yeah, no kidding! I think I am about finished with this site anyway. You have an opinion and people are quick to tell you how wrong your opinion is. I guess I should expect no less from todays society.


----------



## Sound Suggestions (Dec 5, 2010)

^I hear you!

.....They're here, arm yourselves! Lol


----------



## thomasluke (Jun 10, 2011)

CPPTG said:


> Why thank you Dr. Amp! I have read the thread. Since you are projecting a know it all attitude, I could really care less what you think. If you read my review, I state its my test and my comparison. Its what I found and my opinion. I didnt mention any brands and am not attacking Class D. Hard to post on this site without the attacks. Oh well.


If you are going to do a test then opinion doesnt matter at all. Only the results.
Here's your "test" summarized: Hey guys i hooked two amps up today and had listen.
One was class a/b the other d. The a/b sounded better.
Not trying to be a know it all or a dick dude.... But that was your test.


----------



## Randyman... (Oct 7, 2012)

CPPTG said:


> If you read my review, I state its my test and my comparison. Its what I found and my *opinion*.


Level Matching is rule #1 when A/B'ing IMNSHO (at least if you want the results to have any correlation with what's actually happening)...

No harm in testing for your own curiosity - but just know level imbalances will horribly skew your perceived results (and therefore will horribly skew your *own opinion* as well  )

Fun is fun (I love fun!). Facts are facts (I love accuracy). Knowing how to separate them for an accurate result can be the hard part for us humans...


----------



## DAT (Oct 8, 2006)

Level matching. Agreed. If you have questions ask ! We can help 


Sent from my iPhone using Tapatalk.....blah blah blah.


----------



## Darth SQ (Sep 17, 2010)

CPPTG said:


> Yeah, no kidding! I think I am about finished with this site anyway. You have an opinion and people are quick to tell you how wrong your opinion is. I guess I should expect no less from todays society.


Aren't you overreacting just a little?
They're not telling you that your opinion is wrong, they're trying to tell you how you obtained that opinion is flawed.

If I were doing an audible only test, I would take a classic class a/b amp like the PPI Art A600.2 and put it up against the new class d PPI Phantom P600.2, balance the gains of both using a digital multimeter, and then have someone swap them out for me so I wouldn't know which one was which when I was listening.
Then I would do the swapping and see if my opinion had changed from the blind test.











Bret
PPI-ART COLLECTOR


----------



## Sound Suggestions (Dec 5, 2010)

I do agree that properly matching the source ouput level to the input stage of the amplifier is important to be able to take advantage of the full potential of the amplifier...that I agree...but this is not a magical step that turns every amplifier to sound the same OMG I give up!!! I'm selling all my stuff and I'm going shopping to the closest flee market and picking up a set of Legacy 2,000,000 watts amps and calling it a day! Going to bed goodnight!


----------



## CPPTG (Feb 22, 2011)

Sound Suggestions said:


> I do agree that properly matching the source ouput level to the input stage of the amplifier is important to be able to take advantage of the full potential of the amplifier...that I agree...but this is not a magical step that turns every amplifier to sound the same OMG I give up!!! I'm selling all my stuff and I'm going shopping to the closest flee market and picking up a set of Legacy 2,000,000 watts amps and calling it a day! Going to bed goodnight!


I think I will do the same. I will certainly level match the amps. I stated that in an earlier post, but I don't know if anyone read it or not. 

However, I guess I should have also mentioned that I DID change the volume and the gains during my test, for my personal judgement. I just didn't think it was that dang important since I was stating I listened to both, and I prefer the A/B. Good lord, you would think some on here have stock in Class D amps. I stated which one I prefer, that's it. I didn't say you should like this one, or the one I tested or anything.


----------



## Randyman... (Oct 7, 2012)

Sound Suggestions said:


> I do agree that properly matching the source ouput level to the input stage of the amplifier is important to be able to take advantage of the full potential of the amplifier...that I agree...but this is not a magical step that turns every amplifier to sound the same


It's not "Proper Gain Structure" that we are crying about (which is obviously crucial during system configuration and tuning) - it's the LEVEL MATCHING between the two units under test.

If you don't have an accurate reference level to compare the two systems/components/whatever, you'll only be fooling yourself about which one sounds "better" (the "louder" one will ALWAYS sound "better" to a human - it's proven fact).

Again - No harm in swapping amps non-scientifically for a test - but just know the results you get will be all over the map and WILL affect the opinion you derive from said comparison. That's all we're getting at (at least that's all I'm getting at).


----------



## CPPTG (Feb 22, 2011)

PPI-ART COLLECTOR said:


> Aren't you overreacting just a little?
> They're not telling you that your opinion is wrong, they're trying to tell you how you obtained that opinion is flawed.
> 
> If I were doing an audible only test, I would take a classic class a/b amp like the PPI Art A600.2 and put it up against the new class d PPI Phantom P600.2, balance the gains of both using a digital multimeter, and then have someone swap them out for me so I wouldn't know which one was which when I was listening.
> ...


----------



## MarkZ (Dec 5, 2005)

CPPTG said:


> No, I don't think I'm overreacting. I've had this happen on this site before. You state you like something and someone doesn't say they disagree, they start telling you why you shouldn't like it.


That's not exactly what's going on here. What's happening is that you said you went out in the yard and did a dance, and then it rained. If that's how you left your post, nobody would have a problem with it. The problem comes when you say, "and therefore, in my opinion, my dance makes it rain."


----------



## thomasluke (Jun 10, 2011)

CPPTG said:


> I think I will do the same. I will certainly level match the amps. I stated that in an earlier post, but I don't know if anyone read it or not.
> 
> However, I guess I should have also mentioned that I DID change the volume and the gains during my test, for my personal judgement. I just didn't think it was that dang important since I was stating I listened to both, and I prefer the A/B. Good lord, you would think some on here have stock in Class D amps. I stated which one I prefer, that's it. I didn't say you should like this one, or the one I tested or anything.


If you would have read the thread I linked and I mean the whole thread.
You would know my take on the matter.
It's not the way you think it is either.


----------



## thomasluke (Jun 10, 2011)

MarkZ said:


> That's not exactly what's going on here. What's happening is that you said you went out in the yard and did a dance, and then it rained. If that's how you left your post, nobody would have a problem with it. The problem comes when you say, "and therefore, in my opinion, my dance makes it rain."


You made a post earlier in another thread and i'm calling ******** on it.
Because you sir are the smartest ****ing person on here.


----------



## CPPTG (Feb 22, 2011)

MarkZ said:


> That's not exactly what's going on here. What's happening is that you said you went out in the yard and did a dance, and then it rained. If that's how you left your post, nobody would have a problem with it. The problem comes when you say, "and therefore, in my opinion, my dance makes it rain."


Really? I never said Class A/B was better. I said that's what I prefer. I didn't say you should prefer it.


----------



## CPPTG (Feb 22, 2011)

thomasluke said:


> If you would have read the thread I linked and I mean the whole thread.
> You would know my take on the matter.
> It's not the way you think it is either.


I have read the WHOLE thread. I know your take on it. It really doesn't matter to me.

The level setting is a good point, that's why I stated I will make sure to adjust them again.

If I listen to 2 amps side by side and state which one I prefer, why does that mean so much to you? You stated I already had my mind made up. Even if that were the case, what do you care? You could have easily said I prefer Class D, I have done my own comparison, this is how I did it, and I like this. But instead, you decide to start telling me that how I did my test was wrong and I already had a preconceived mindset.

I didn't name any manufacturers precisely for this reason. My purpose was not to bash a particular amp, or even Class D for that matter. I never say anywhere that Class D is bad. I just say I prefer Class A/B. I don't understand where the problem is.

But, its whatever. I've had my say, and its enough. Certainly not worth any more effort on here.


----------



## ErinH (Feb 14, 2007)

All of these sighted tests are fundamentally flawed. You guys are talking about level matching when the test is still sighted. Inherently, there is a bias due to this whether we choose to acknowledge it or not. Where that bias is is dependent upon the person doing the comparison. The fact there is no blind testing is reason enough to not worry yourselves with it. Not to mention performing the test in an ABX fashion. 

If we want a real discussion on audibility then it needs to be performed legitimately. That means blind testing, with multiple units under test, and enough samples to yield meaningful analysis. Should this actually be conclusive, understanding why the results were what they were by testing the amplifiers electronically would be the next step to determine if its a faulty product or just a poor design _of that particular sonically 'inferior' device_. This then still only applies to the specific devices tested as blanketing all "class X" types by testing one particular model of each subset is too generalized. Until then the arguing of "amp sound" is meaningless. It's like arguing which kind of fairy dust is prettier.


----------



## 07azhhr (Dec 28, 2011)

CPPTG said:


> .... knowing that there are a couple of issues that hinder their performance somewhat, when it comes to full range.


Are you willing to elaborate on this statement?



CPPTG said:


> (an old Kenwood that probably puts out about 1 or 2v) so that's what I used.
> 
> The very first thing that I noticed was the difference in output. With the volume on the CD player set exactly the same, the output on the Class D was much less. The 22.5w A/B seemed to be about 30% louder over the 70w D. I am by no means an expert, but this was surprising to me.


That looks like a RF Punch 45 from the specs and if so the gain range is probably maxed at 2v so that HU and amp are a great match at any gain setting when compared to a newish amp that probably goes up to 6v. What this means is that when you set them to minimum the AB amp is closer to it's rated output and is probably even putting out more wattage then the class D amp. This is THE cause of this 30% difference in volumn. To be honest this should not cause one to be suprised as it is a known fact. 

I would suggest giving it another shot and see if you still feel the same way. Also try some of the new class D full range amps and see if they too sound similar to these findings. You may be suprised and you may not be but atleast no one can say you did not try right?


----------



## 07azhhr (Dec 28, 2011)

CPPTG said:


> I never say anywhere that Class D is bad. I just say I prefer Class A/B. I don't understand where the problem is.
> 
> But, its whatever. I've had my say, and its enough. Certainly not worth any more effort on here.


The things you said as quoted below are suggesting just that.






CPPTG said:


> I've wondered what they sounded like, knowing that there are a couple of issues that hinder their performance somewhat, when it comes to full range.
> 
> 
> 
> ...


----------



## Hoye0017 (Mar 23, 2010)

t3sn4f2 said:


> NwAvGuy: What We Hear


Good reading. I completely agree. It sort of says something I've thought for years and have posted here before. this was about whether caps do anything:

Quote

I think this is the source of the "lying" that markZ is referring to. But it's not usually them lying to us. It's more that they are lying to themselves. 

I personally believe the entire audio snake oil market is based on people's brains wanting and expecting an improvement. 

The best part of that is that you don't have to feel guilty for selling things that are a little "oily." If the person is enjoying a perceived improvement, real or imagined, they are still getting a value. In the end, a system that sounds better to them is all they want. Who cares if no one else can hear it.

Just one more thing that keeps me as a hopeful doubter.

End quote.

I probably fall for my brain's expectations too but I'm ok with it. I have no problem with accepting the concept of "perception is reality" in the consequence-free world of something as trivial as audio reproduction systems. 

That said, I would still say the test done by the OP is way too flawed to make any judgement on one amp topography vs another.


----------



## Hoye0017 (Mar 23, 2010)

Meant "topology," sorry maybe one too many Patron shots tonight. Hope no one googled the mapping of amplifiers

Hmmmmm..... I wonder if my preference for patron silver is based on the marketing and price point that make my brain think I should like it more.


----------



## jimboman (Jun 24, 2008)

First off, let me say that I have never heard a class d amp.
But we have seen a few posts that say the same thing about how class d amps sound compared to a/b for full range.

Nothing seems too flawed to me as far as the test the OP has run. 

The only issue I see is that they were run at 8 ohms and that an older class d amp was used.

I would be very hesitant to run a class d amp up front. I know thier size and power requirements are very tempting though.


----------



## Richv72 (May 11, 2012)

CPPTG said:


> Yeah, no kidding! I think I am about finished with this site anyway. You have an opinion and people are quick to tell you how wrong your opinion is. I guess I should expect no less from todays society.


I wouldnt take it personally man, some issues are touchy subjects for some people. It's interesting to see different points of view on various topics, and they can also be fun to watch sometimes.


----------



## Darth SQ (Sep 17, 2010)

Hoye0017 said:


> Good reading. I completely agree. It sort of says something I've thought for years and have posted here before. this was about whether caps do anything:
> 
> Quote
> 
> ...


In the Matrix, class d always wins.


Bret
PPI-ART COLLECTOR


----------



## qwertydude (Dec 22, 2008)

I do know one thing. I have the Topping TP-22 and it positively kills the FM radio reception on my little MP3 player with an FM tuner it also sometimes interferes with the capacitive touchscreen on iPhones when connected.

I used to have a full range class D amplifier a few years back in one of my cars and it to sometimes interfered with FM radio reception in my car, especially AM radio. I couldn't get any AM radio stations with it installed.


----------



## 07azhhr (Dec 28, 2011)

qwertydude said:


> I do know one thing. I have the Topping TP-22 and it positively kills the FM radio reception on my little MP3 player with an FM tuner it also sometimes interferes with the capacitive touchscreen on iPhones when connected.
> 
> I used to have a full range class D amplifier a few years back in one of my cars and it to sometimes interfered with FM radio reception in my car, especially AM radio. I couldn't get any AM radio stations with it installed.


That sucks. The PPI Phantom I have was in my car and now is in my girls car and it hasn't interfered with the reception in either one. Hopefully that kind of issue is a thing of the past.


----------



## Hoye0017 (Mar 23, 2010)

cajunner said:


> If making a thread that puts class D in a negative light, floats your boat-
> 
> don't complain about the waves!
> 
> I really don't believe this "test" advanced anything in the nature of car audio and my post adding to this thread is also an irrelevant and spurious interjection.


This is probably the most honest and true post I have ever read. 

Nice to see someone who's truly honest with themselves and not trying to sound like the expert. 

I wish I could be so self-effacing. God knows my posts could use less ********.


----------



## WRX/Z28 (Feb 21, 2008)

OP, I sympathize with you, and I see your point of view. You believe that you performed a fair test on a level playing field. The biggest mistake here is assuming that the gain being set at the bottom on both amps meant they were both set equally. This stems from believing that the gain is a volume control. It isn't. Gain's are more like a flood gate for signal from your radio. 

Imagine this, you have two hoses, both with nozzles that can be adjusted. One nozzle can be adjusted from wide open to 1/2 closed. The 2nd nozzle can be adjusted from wide open to 3/4 closed. You turn both nozzles to the point where they are closed the most. The nozzle that only closes 1/2 way has more water still coming out of it than the nozzle that closes 3/4 of the way. This is like the gains on the 2 amps. If the A/B was much louder even though it was rated for 1/3 the power capability, the simple explanation is that the gain control was different. Because you weren't understanding how a gain control works, you assumed the louder amp was better/made more power. The reality is that you were choking off the input from the quieter amp. 

You need to try the test again, and this time measure the output from the amp with a DMM (digital multimeter) with pink noise coming from your source. Adjust the amp with the lower outputs gain until it matches the amp with the higher output (or as close as you can get). Then switch back and forth listening to music. If you do this, you will see that both amps sound very similar, if not identical. because this way we have ensured that they have identical amounts of output with identical amounts of input. 

Another way to think of this: If you use that amp with 2 different radio's, one has a max 2.0v rca output with the volume at 35. The next radio has a max 4.0v rca output with the volume at 35. With the gains set all the way down on your amp, switch between the radio's with the volume adjusted identically. The 4.0v radio will be louder through the same amp at every step on the volume control. This is because it can output more signal. This is the reason amps have gain controls, so you can match levels between different radio's and different amps. 

Your amp can't make any output without signal coming in. This is why even with the gains set on max, your amp will have 0 wattage coming out of it until you plug in a radio outputing signal. 


I hope this makes sense, i'm really trying to think of the simplest way to explain it without sounding like a dick. 

I hope this has come across as constructive advice, and not just telling you that you're wrong.


----------



## MUGWUMP (Jan 29, 2012)

CPPTG said:


> PPI-ART COLLECTOR said:
> 
> 
> > Aren't you overreacting just a little?
> ...


----------



## BuickGN (May 29, 2009)

No one has ever gotten out of my car less than impressed and I've gotten a few people with shocked looks once they hear that it's using class D amps. I'm not bragging about my car but I've found that if people don't know they're listening to class D amps, they tend to be impressed with the sound. Not so much when they know what's in the car before listening. I think I have converted a few people so far to full range class D amps.

I've said it way too many times but after running my McIntosh A/B amp over and over and over against my JL HD amps I couldn't justify the real estate and the inefficiency of the Mac. I love the Mac because it's so damn cool looking and it's rep but the HDs are the same or superior in every category as I'm sure any good class D amp would be. This was a flawed test in that with the exception of the one time I had a friend swapping amps, it was not a blind test. I expected the Mac to sound better, subconsciously I think I wanted the Mac to sound better but it just didn't. It didn't sound worse either, there just wasn't a real difference. Maybe I'll try again with my new tweeters that are much more revealing.


----------



## ChrisB (Jul 3, 2008)

BuickGN said:


> No one has ever gotten out of my car less than impressed and I've gotten a few people with shocked looks once they hear that it's using class D amps. I'm not bragging about my car but I've found that if people don't know they're listening to class D amps, they tend to be impressed with the sound. Not so much when they know what's in the car before listening. I think I have converted a few people so far to full range class D amps.
> 
> I've said it way too many times but after running my McIntosh A/B amp over and over and over against my JL HD amps I couldn't justify the real estate and the inefficiency of the Mac. I love the Mac because it's so damn cool looking and it's rep but the HDs are the same or superior in every category as I'm sure any good class D amp would be. This was a flawed test in that with the exception of the one time I had a friend swapping amps, it was not a blind test. I expected the Mac to sound better, subconsciously I think I wanted the Mac to sound better but it just didn't. It didn't sound worse either, there just wasn't a real difference. Maybe I'll try again with my new tweeters that are much more revealing.


The sad thing is people have this preconceived notion that amplifiers with class d power supplies are inferior sounding when compared to their favorite inefficient class ab relic from the 80s. If they know beforehand, they always hear a difference. If they don't know until afterwards, they always end up shocked that they are listening to class d when you show them. Crazy how that works, isn't it?


----------



## BuickGN (May 29, 2009)

ChrisB said:


> The sad thing is people have this preconceived notion that amplifiers with class d power supplies are inferior sounding when compared to their favorite inefficient class ab relic from the 80s. If they know beforehand, they always hear a difference. If they don't know until afterwards, they always end up shocked that they are listening to class d when you show them. Crazy how that works, isn't it?


Sure is. I'm trying not to piss as many people off anymore but I can't imagine ever not doing a class D just because I can't find a single reason not to and the advantages are already known. This is my opinion, only my opinion but there's no reason to use class A/B :shocked: I know that's a really bold opinion but it's how I feel. That's not saying class D sounds better, it's just saying that there is no difference in sq (IMO) and coupled with the size and efficiency, why would you use anything else?

Plus using an "average" class D amp frees up more money for overpriced speakers. But seriously, after being complimented and revealing what equipment I'm using, the speakers aren't what's impressing people, they can't get over they were just listening to a full class D system without these so called "digital artifacts" or "coldness". It's become one of my favorite things to do, to not let people know what amps I'm running until we're done listening. Amazingly I would say 50% of the time where people have known what they were listening to have claimed to hear these class D flaws while not a single person has heard these flaws that did not know it was class D.


----------



## IDGAF (Dec 27, 2009)

OP, if, at the end of your test, you had said you preferred the class D, you still would have caught the same amount of ****.

Furthermore, the flak that you are catching is for your own good. Because if you don't pigeonhole yourself with 30 year old collector's items, you open up a whole new world of choices.

No one is telling you that you're wrong. Just that the method you used to arrive at your conclusion is flawed.


----------



## trojan fan (Nov 4, 2007)

ChrisB said:


> The sad thing is people have this preconceived notion that amplifiers with class d power supplies are inferior sounding when compared to their favorite inefficient class ab relic from the 80s. If they know beforehand, they always hear a difference. If they don't know until afterwards, they always end up shocked that they are listening to class d when you show them. Crazy how that works, isn't it?


Interesting, because my teenage nieces will only wear clothes with certain designer labels. We all at one time or another judge a book by it's cover


----------



## CENTRAL (Dec 13, 2012)

Automotive class D amps are still evolving...

I believe that tha latest generations are starting to look the old guys right in the eyes.

Same thing happened with digital cameras a few years back. 

Anyone still using a film camera?


----------



## Darth SQ (Sep 17, 2010)

Maybe class d speakers would match up better.


Bret
PPI-ART COLLECTOR


----------



## trojan fan (Nov 4, 2007)

CENTRAL said:


> Same thing happened with digital cameras a few years back.
> 
> Anyone still using a film camera?



Good point, I have not owned a non-digital camera in almost ten years


----------



## trojan fan (Nov 4, 2007)

PPI-ART COLLECTOR said:


> Maybe class d speakers would match up better.
> 
> 
> Bret
> PPI-ART COLLECTOR


Where do you get those at....


PS...how's the bad boy coming along?


----------



## Sound Suggestions (Dec 5, 2010)

trojan fan said:


> Good point, I have not owned a non-digital camera in almost ten years


Come on...still doesn't make it better...someone behind a camera that knows what they are doing you still can't match old film technology! That's a fact...go buy your efficient class D amp and be done with it! I prefer class a or class a/B...on my mids/highs anyhow, so what they are 60% efficient, and the class d's are 85/90% efficient, so what the A/B generates more heat...i dont f/n care! What sounds better! That's what I want want....If the class D sounds better one day...i will buy a class D...but for now they don't 

We are becoming a society that does not justify paying for quality...we demand quantity for our dollars and it's pushing these manufacturer to cut cost to give us more and more and more...me I don't mind paying more money for better quality components...not for every body

The way you guys talk its like research and development means nothing! You buy BlackBerry I'll buy an apple iPhone 5 and keep telling yourself the crackberry is better. you guys most be sporting the same amp you bought 10 years ago! These types of debate are fantastic...

I need to know; all the folks that say class D sound just as good...please list your amplifier that you are using (I'm assuming class D...and from which amp did you have b4)

That should be interesting


----------



## bbfoto (Aug 28, 2005)

Sound Suggestions said:


> Come on...still doesn't make it better...*someone behind a camera that knows what they are doing you still can't match old film technology! That's a fact*...go buy your efficient class D amp and be done with it! I prefer class a or class a/B...on my mids/highs anyhow, so what they are 60% efficient, and the class d's are 85/90% efficient, so what the A/B generates more heat...i dont f/n care! What sounds better! That's what I want want....*If the class D sounds better one day...i will buy a class D...but for now they don't *
> 
> We are becoming a society that does not justify paying for quality...we demand quantity for our dollars and it's pushing these manufacturer to cut cost to give us more and more and more...me I don't mind paying more money for better quality components...not for every body
> 
> ...


Hey Sound Suggestions,

Do you have any scientific evidence that conventional film photography/imaging is technically superior to digital imaging technology, and/or that Class A/B amplifiers sound better as opposed to Class D amplifiers?

I don't have a problem with your personal _preference_ towards one or the other, but you really can't make such statements without the facts to back it up. 

Regarding film or digital photography, I have been a professional advertising photographer for over 30 years, which is quite a few years before there was digital technology available at all.

But for at least the last 6 to 7 years, none of the multi-million dollar, Fortune 500 companies or the mega ad agencies that have hired me or my collegues, have requested us to shoot conventional (analog) film. The cost differential is not a barrier in any way. If conventional film was technically superior in any way, believe me, clients would request it. They do not.  Sure, there are some folks who aesthetically prefer the "look" and the process/workflow of shooting film, but I don't think that you would come across too many educated professionals that would argue that film is technically superior to digital capture technology.

For further confirmation you can reference two multi-billion dollar industries that do not compromise when it comes to imaging, and those would be the military and medical fields. They are both using digital imaging technologies, and in both fields, real lives are at stake.

Have you been involved in any legitimate double-blind/ABX Class A/B vs Class D amplifier listening tests with modern technologies/amplifiers to determine for yourself that one type is => the other?

I love Old School car audio AND photography just as much as the modern equivalents...just trying to provide some food for thought. 

It would be awesome to have a World Champion SQ Car at IASCA/MECA/USACi Finals that is set up with level-matched Class A-A/B vs. Class D amplifiers with everything else in the system the same, and all amplifiers hidden from view. Then have 4 or 5 judges score the car at least one day apart using an unmarked/random switch to choose between the amplifier setups. Now that would be interesting!


----------



## Hanatsu (Nov 9, 2010)

BuickGN said:


> No one has ever gotten out of my car less than impressed and I've gotten a few people with shocked looks once they hear that it's using class D amps. I'm not bragging about my car but I've found that if people don't know they're listening to class D amps, they tend to be impressed with the sound. Not so much when they know what's in the car before listening. I think I have converted a few people so far to full range class D amps.
> 
> I've said it way too many times but after running my McIntosh A/B amp over and over and over against my JL HD amps I couldn't justify the real estate and the inefficiency of the Mac. I love the Mac because it's so damn cool looking and it's rep but the HDs are the same or superior in every category as I'm sure any good class D amp would be. This was a flawed test in that with the exception of the one time I had a friend swapping amps, it was not a blind test. I expected the Mac to sound better, subconsciously I think I wanted the Mac to sound better but it just didn't. It didn't sound worse either, there just wasn't a real difference. Maybe I'll try again with my new tweeters that are much more revealing.


Couldn't have said it better myself  I'd run class D fullrange any day.


----------



## Hanatsu (Nov 9, 2010)

Sound Suggestions said:


> Come on...still doesn't make it better...someone behind a camera that knows what they are doing you still can't match old film technology! That's a fact...


Have some issues with this. It is not a fact. 'In fact' this has been debated just as much as this class A/B-D discussion. The difference here is that we do have the facts, we know both techniques limitations and it can expressed in numbers. So far I've seen NOTHING to prove that A/B is better or that class D is worse. The parameters are electrical, it can be measured and put into numbers. I simply don't trust people and their sighted/experienced differences, no offense - that goes for everyone.

Been a photographer for 9 years now and I'd say while film has its place, it's not superior to digital cameras nowadays. If we comparing image detail only, the digital cameras couldn't match film until the later years. In a 35mm film photo we have an equivalent resolution of approximately 13-15mpix. With a good performing digital full-format 35mm sensor we can attain greater resolution than that, assuming the lens isn't a bottleneck. Dymamic range and image (color) depth are other factors, some times not as important as one would think. 



Sound Suggestions said:


> go buy your efficient class D amp and be done with it! I prefer class a or class a/B...on my mids/highs anyhow, s*o what they are 60% efficient, and the class d's are 85/90% efficient*, so what the A/B generates more heat...i dont f/n care! What sounds better! That's what I want want....If the class D sounds better one day...i will buy a class D...but for now they don't
> 
> We are becoming a society that does not justify paying for quality...we demand quantity for our dollars and it's pushing these manufacturer to cut cost to give us more and more and more...me I don't mind paying more money for better quality components...not for every body


Don't get it... there are possibly no high quality components in class D amps?

The average efficiency difference can be bigger than that, efficiency are relative to output as well. At low output an A/B amp might only be 20-30% efficient while the class D is 85-90% efficient. Check the graph on this site;

Class-D Amplifiers



Sound Suggestions said:


> The way you guys talk its like research and development means nothing! You buy BlackBerry I'll buy an apple iPhone 5 and keep telling yourself the crackberry is better. you guys most be sporting the same amp you bought 10 years ago! These types of debate are fantastic...
> 
> I need to know; all the folks that say class D sound just as good...please list your amplifier that you are using (I'm assuming class D...and from which amp did you have b4)
> 
> That should be interesting


Used Genesis dual mono, DLS Reference and Ultimate, Alpine PDX series, JBL GTO, some newer HK amps, Harman kardon/Orion/Macrom old school amps and my best friend has currently a JL 900/5 amp in his car, before that an Audison LRx 5.1 amp. We have compared two of these amps in a home audio environment with high end ScanSpeak Illu 3-way towers, properly level matched and found very little difference between his JL amp and my genesis amps I ran back then. Better or worse, couldn't tell. I'm no audiophile but do know if something sound bad or not. Between these two amps there were no big audible difference, it still doesn't justifies saying class A/B-D sound sound different/better/worse. Simply not enough data to make a valid conclusion and I'm not qualified enough/doesn't have the means to make valid measurements on amps either. All I can say is between these two, we couldn't hear a big enough difference to pass an ABX test, which was pretty much random and inconclusive.


----------



## quality_sound (Dec 25, 2005)

Sound Suggestions said:


> Come on...still doesn't make it better...someone behind a camera that knows what they are doing you still can't match old film technology! That's a fact...go buy your efficient class D amp and be done with it! I prefer class a or class a/B...on my mids/highs anyhow, so what they are 60% efficient, and the class d's are 85/90% efficient, so what the A/B generates more heat...i dont f/n care! What sounds better! That's what I want want....If the class D sounds better one day...i will buy a class D...but for now they don't
> 
> We are becoming a society that does not justify paying for quality...we demand quantity for our dollars and it's pushing these manufacturer to cut cost to give us more and more and more...me I don't mind paying more money for better quality components...not for every body
> 
> ...


Current: JL HD900/5 and HD600/4

Previous amps from last to as far back as I can remember broken down by system: Zapco DC Reference 650.6/750.2
Arc Mini 125.4/500.1
Arc XXK 4150/2500/2050
PPI PCX450/2100
Soundstream Rubicon 604/702
Kicker ZX360/ZR600
RF punch 40dsm/Soundstream Granite 60.2

I might be forgetting some but it's fair to say I have some experience with A/B amps and my JLs easily match any of them.


----------



## 07azhhr (Dec 28, 2011)

Sound Suggestions said:


> I need to know; all the folks that say class D sound just as good...please list your amplifier that you are using (I'm assuming class D...and from which amp did you have b4)
> 
> That should be interesting


Until about a month ago I was running my whole system off of my PPI Phantom 900.4 class D amp. I needed 7 channels of amplification and was going to switch over to the Soundstream Tarantula Nano class D (same exact amp as the PPI) amp soley for the looks. I never once felt this class D amp had any difference in sound from my many previous class ab amps. Well that is except the zero noise floor. 

Ironically, I am now running class ab Zapco DC ref amps but that is soley for the features as I needed 2 more channels of T/A availible. Since my PPI class d was running my 3 way fronts in passive config I decided to swap in just one 2 channel Zapco to see if I could tell any differences. While this wasn't a blind test or even an a vs b switching back and forth type of test I was going from a mid level class d amp to a somewhat hi level class ab amp. So if there was to be any bias, it should have been for the new amp, the class ab lol. Other then a volumn level difference going from 145w to 50w per side there was no other decernable difference in the sound. I then swapped the 50w per side DC200.2 for the 100w per side DC350.2 and listened again for another few days. Again there was no sound difference other then shear volumn of which I now had pretty much the same as with the PPI. 

The PPI (class d amp) is now in my girls car driving her 2 way fronts + sub and is temporarily replacing her old school SS ref405 amp while it is to go out for repair. Again here in this car it was just a swap of amps and nothing else. No blind test nor switching back and forth but still no decernable difference in sound. Just a slight volumn difference do to the wattage difference. She needs 5 channels of amplification and if she did not like the looks of the SS amp so much I would not hesitate to get her a SS class d 5 channel amp to run in there.


Some other amps I have ra before this car.

MTX Jackhammer class D JH650 sub amp + MTX class ab forget model 4 ch fr/rear
Rockford Power 800a4 front's + sub
Rockford " " subs + RF Power 600a4 fr/rear
" " 500a2 " + same as above
PPI art series A600.2 + A404 fr/rear
ADS PQ10 x 2 
ADS PQ10 fr/rear + PQ20 subs
Pioneer GM-H50 x 2 fr/rear + GM-H100 sub
Rockford Power Mosfet 300 ran in way too many ways to list this amp was the most impressive amp I have ever had the pleasure to use
Various Rockford DSM amps
Various other origional punch amps (i.e. Punch 45 punch 150)
Orion HCCA 225
Phoenix Gold MS275 and M44
Various Hifonics series 7 generation amps
Old school Coustic amps of various forgoten model numbers


----------



## RNBRAD (Oct 30, 2012)

bbfoto said:


> For further confirmation you can reference two multi-billion dollar industries that do not compromise when it comes to imaging, and those would be the military and medical fields. They are both using digital imaging technologies, and in both fields, real lives are at stake.


The main reason the switch in the medical field to digital was not that is was that "superior" in image quality, it is mainly due to the ability to access, trasnfer, and store this information very easily. I look at chest x-rays almost daily (digitally). I can't tell a superior or inferior quality difference over the analog pictures. Visually I can't discern a difference, so might as well encorporate it cause it brings alot of benefits. It's like digital music, of course there is analog purists that love vinyl as well as those that love analog pictures and the process. 

Class D will be the same. Once the technology reaches a point where you can't tell the difference between it and A/B, why not use it? It brings even more benefits to the table. Pioneer is using class D in the "Elite" brand now. You know they aren't risking their high end name on class D if it's inferior. I'm betting class D will be the standard in amplifier design in the not to distant future. It's just in the "working the bugs out" phase like LCD was not too long ago. Now it's the standard.


----------



## LovesMusic (Mar 29, 2012)

Well, First it is my personal preference to run class a or a/b with mids and highs...

I enjoy messing around trying to play an electric guitar too(for years)...

I switched out a JL JX 2ch amp for a JL xd and HD comparing certain Derek Trucks Band songs, he plays amazing slide on a gibson SG. In my humble honest opinion the cheap a/b JX amp gave the guitar more emotion and authority, I felt the licks were conveyed better, I dont know why pleasent distortion..? Does it really matter why I liked it better tho...

Heres something to think about...
Derek must use some pedals maybe some compression and certain pots selected, Im sure some distortion and positively a tube amp. Artists spend DECADES getting their specific "sound". Sit Derek down and let him listen to his own music on yout audio system or maybe switch out a couple amps(a/b to D)...GUARENTEE he has a preference!!!! I can promise he will feel one such amp reproduces his music his sound the way he wants it too...Sure its subtle but it is there and isnt what your audio system is all about... And if you play an instrument youll understand this holding true.

So which does he feel reproduces HIS music better, class a/b or d..
No wrong or right answer here just something to think about

Then we weretalking about using film or digital photography


How about use of the ancient tube amp...LOTS of ppl swear by a tube amp, a good old 1960 fender deluxe reverb will almost undoubtedly be the musicians pick above any modern day solid state amp...

With the "efficiency", "reliability" and "TOLERENCES" of modern transistors you wouldnt think this would be the case....


----------



## AAAAAAA (Oct 5, 2007)

Sound Suggestions said:


> Come on...still doesn't make it better...someone behind a camera that knows what they are doing you still can't match old film technology! That's a fact...go buy your efficient class D amp and be done with it! I prefer class a or class a/B...on my mids/highs anyhow, so what they are 60% efficient, and the class d's are 85/90% efficient, so what the A/B generates more heat...i dont f/n care! What sounds better! That's what I want want....If the class D sounds better one day...i will buy a class D...but for now they don't
> 
> We are becoming a society that does not justify paying for quality...we demand quantity for our dollars and it's pushing these manufacturer to cut cost to give us more and more and more...me I don't mind paying more money for better quality components...not for every body
> 
> ...


LMAO

You are like a girl that just spouts off emotional feelings instead of anything logical, researched and thought out.


----------



## MarkZ (Dec 5, 2005)

LovesMusic said:


> Heres something to think about...
> Derek must use some pedals maybe some compression and certain pots selected, Im sure some distortion and positively a tube amp. Artists spend DECADES getting their specific "sound". Sit Derek down and let him listen to his own music on yout audio system or maybe switch out a couple amps(a/b to D)...GUARENTEE he has a preference!!!! I can promise he will feel one such amp reproduces his music his sound the way he wants it too...Sure its subtle but it is there and isnt what your audio system is all about... And if you play an instrument youll understand this holding true.


Totally absolutely correct. I can usually identify guitar amplifiers just by the sound. Pedals too. Even swapping out the tubes can yield pretty big differences. I have difficulty identifying pickups, but I know some people who can.

But remember, music production and music *re*production are two _totally different_ things. Different goals, different strategies, different considerations.

Guitar players almost invariably overdrive their amps. My last Ampeg combo amp was rated into 50% THD.  Loved that amp, it was nasty. I had a whole different array of pedals that I used for that amp as opposed to my Hiwatt, just because the sound was _so_ much different. 

But in *re*production, we're no longer _creating_. A painter is totally different from the guy who hangs special lighting to try to showcase the art on his wall. When we try to shape the sound, it's almost always to account for some problem in the reproduction chain (including environment), not as an attempt to create. You can try to insert yourself into the creative process by further tailoring the sound in some interesting way -- there are no rules against this -- but IMO that's not really easy to achieve with the tools that car audio manufacturers provide. The goal of amplification in *re*production is almost invariably the "straight wire with gain" approach. There are some deviations from this strategy, but not very common in the car audio arena IME. And honestly? "Straight wire with gain" is pretty easy to achieve. Building amps that color the sound in a favorable/interesting way is much harder.


----------



## LovesMusic (Mar 29, 2012)

Mark, Sounds like you have quite the equipment for days worth of jamming!

Isnt that what music is all about... a sound
a sound created in conjunction with other pieces of the puzzle.
a sound to call your own, and if you dont like "a sound" how about an expression...
countless ways of manipulation...creating that is, like you stated
but itll always be preferences...and nothings a matter of fact.

The way I figure it is Im not good enough to upgrade the 30w Roland Cube amp I have lol though I can and will say that a guitar out of the Roland is hands down superior in everyway to any of my car/home speakers.

The way I can compare it, is listening to a whip crack through a speaker and then the whip crack right behind you....no comparison

What defines that? Mark plug in your guitar (maybe a splash of reverb) and give the strings a nice chuck...Theres no way we are going to reproduce that beautiful chuck in a car regardless of equipment and yada yada...


You are so right about amplification, straight wire and some gain.. KISS

That is simple class A amplification tho no? wire and resistor in pre amp and wire and resistor in output stage... 

Then we want a little bit more efficiency so we integrate some of a class B, but what did we lose adding the efficiency, we had to lose something...

Now were at class D and we have rail voltage FM modulation switching what did we lose from our original signal to get here? we lost something...

I never liked the idea amplification coloring but where did we introduce it, at what point..I cant say for sure I know what it sounds like, I just call it different..

I dont know the answers Im just throwing ideas around...


----------



## MarkZ (Dec 5, 2005)

LovesMusic said:


> You are so right about amplification, straight wire and some gain.. KISS
> 
> That is simple class A amplification tho no? wire and resistor in pre amp and wire and resistor in output stage...
> 
> ...


But you _don't_ have to lose something. Doug Self showed in his last book that a class B design can compete with a class A design _and_ achieve much greater effiiency. The key is to get the class B amp to be perfectly symmetrical -- which requires a greater parts count than most companies are willing to use -- but even simple modern conventional designs can get pretty close. And by "close", I mean fractions of a percent of distortion, 20-20k response within a dB, stability, noise rejection, etc.

So I reject the idea that you have to lose something to get something else. I think we're so used to tradeoffs in car audio that we sometimes imagine tradeoffs where they don't exist. Sometimes, technological advance allows you to improve efficiency, reliability, output, reduce price, and reduce distortion all at the same time! 

Think about computers. How come people aren't trying to recapture their "old school" Pentium II desktops that used to cost $1500? 

I don't think class B or A/B designs will ever disappear though. They're an elegantly simple circuit to achieve moderate outputs at low cost and parts count. They're also the centerpiece of class H designs that also hold some promise and that we're seeing crop up in car audio in recent years. [class G and H have class A/B or B output stages... class G and H really shouldn't be considered separate classes IMO]


----------



## ChrisB (Jul 3, 2008)

Sound Suggestions said:


> I need to know; all the folks that say class D sound just as good...please list your amplifier that you are using (I'm assuming class D...and from which amp did you have b4)
> 
> That should be interesting


Here is a list of what I owned from 2007 to present:

Linear Power
2 - 5002
5 - 1502IQ
2 - 652
1 - LP150
1 - 1752
1 - 2.2 HV
1 - DPSQ50
1 - DPS 500

Rockford Fosgate
1 - punch 150
1 - power 1000
1 - Punch 300x
1 - 25 to life Power 1000
1 - 25 to Life Punch 150
1 - Power 351s
1 - Punch 5002

Orion
3 - 280 gx
1 - 250 sx
1 - 275 sx
7 - HCCA 225 Digital Ref
1 - HCCA 225 g5
1 - HCCA 250 G4

Lunar
2 - L60x2
2 - L1500
1 - L2125
1 - L450
1 - L100x2
1 - L2100
1 - L2200

Others

1 - Alpine PDX V9
1 - Alpine PDX-5
1 - Cerwin Vega EXL-400.4
1 - Clarion DPX1851
1 - Crossfire BMF1000d
1 - JL Audio 500/1
1 - JL Audio HD900/5
1 - Memphis 16-PR1.5KD
1 - Memphis 16-PR2.75
1 - Soundstream Reference 700s
1 - Stetsom V 1K5 H 1 Ohm
1 - Zapco Z100s2
1 - Zuki Eleets 4

Currently, I am running a Lunar L450 (4x50 class ab) and a Lunar L1500 (1x500 class d). The ONLY reason I am not running another JL Audio HD900/5 is because I already owned the Lunar amplifiers. 

OTOH, I will *NEVER* own another Alpine PDX amplifier, even if they do fix the issues. I had problems with both the PDX-5 and the PDX V9, so Alpine has lost me as an amplifier customer.


----------



## WRX/Z28 (Feb 21, 2008)

Do you guys wonder how much of the nonsense we constantly see about class a/b amps sounding better than class D stems from the unfortunate order in which they were named/invented. 

IE: If Class D amps had been named Class A, and A/B were actually named D, would people continue to insist A/B are better (maybe from a pyschological predisposition to A's and B's being better than D's since the first day you're in school)

or is it just resistance to learning/change?


----------



## MarkZ (Dec 5, 2005)

I think a lot of it comes mostly from the idea that you can't get improved efficiency without giving something else up.


----------



## WRX/Z28 (Feb 21, 2008)

MarkZ said:


> I think a lot of it comes mostly from the idea that you can't get improved efficiency without giving something else up.



So these people believe that carburetors are better than fuel injection? 

The least efficient amps sound the best? 

HD plasma/lcd televisions are sub par to 20 year old tube tv's? 

Do you guys that are sticking to your guns really believe that so many reputable companies would create full range Class D and tout them as their premium line (Ala JL audio, Alpine) over their cheaper class a/b amps if they sounded worse?


----------



## sqshoestring (Jun 19, 2007)

I ran a kicker 5ch that was 4x70rms, it would get a little hairy on the top end but was loud for 70rms. Ran an alpine 4x75 nice mrd(?) with the digital stuff on it, it was pretty close but cleaner at full tilt....or cleaner before it fell on its face from THD. Ran an old 4x50 alpine and another older 5ch 4x50 alpine. Ran a 4x50 dragster that worked well. Ran some others I forget. Then put in a new kappa Z 4ch class D and it sounds comparable to the best of those...except it has 125rms/ch so it has more power no doubt. 95% of my listening is not at full tilt even with a 4x50.

If a class D can't compete, it is only because they built a piece of crap to start with. A class D amplifier is now a high school project for electronics....take a look inside your phone....


----------



## Niebur3 (Jul 11, 2008)

WRX/Z28 said:


> So these people believe that carburetors are better than fuel injection?
> 
> The least efficient amps sound the best?
> 
> ...


Class D started out with a rough beginning and it is just now (I would say, IMHO, starting with the JL HD's) coming into its own. 

How many would use a Full Class D setup from pretty much any of the Class D amps made 10+ years ago?

It is VERY hard to change perception after the fact.

Just think how different the landscape would be today if the JL HD's were the 1st Class D amps put on the market.


----------



## Richv72 (May 11, 2012)

ChrisB said:


> The sad thing is people have this preconceived notion that amplifiers with class d power supplies are inferior sounding when compared to their favorite inefficient class ab relic from the 80s. If they know beforehand, they always hear a difference. If they don't know until afterwards, they always end up shocked that they are listening to class d when you show them. Crazy how that works, isn't it?


OH NO YOU DIDNT!


----------



## trojan fan (Nov 4, 2007)

ChrisB said:


> Here is a list of what I owned from 2007 to present:
> 
> Linear Power
> 2 - 5002
> ...



You remind me of my wife and all her shoe's sine 2007....:laugh:


----------



## Darth SQ (Sep 17, 2010)

trojan fan said:


> You remind me of my wife and all her shoe's sine 2007....:laugh:


What is it about wive's and their shoes anyway?
The stuff she chooses now to go out on a date in was only acceptable if you were a stripper just 15 years ago. 
I should post a pic of her closet.


Bret
PPI-ART COLLECTOR


----------



## ChrisB (Jul 3, 2008)

trojan fan said:


> You remind me of my wife and all her shoe's sine 2007....:laugh:


I learned my lesson along the way. Amplifiers are commodity items and changing speakers will usually net a huger audible result than swapping amplifiers. Well, except for the Alpine PDX amplifiers with their hissing and turn on/off thump. If I wanted something that popped at turn on and had hiss, I'd just go back to looking for relics from the 80s on eBay. Only problem with said 80s relics is they are HUGE, inefficient, and may have other age related issues compared to their modern day, brand new, class d counterparts that have a warranty.

With that said, I turned over a new leaf. If one believes their 20+ year old relics are better than something like the JL Audio HD series, then so be it. They have their reasons for running what they run, and I have mine. At least choice of gear is one of the few freedoms that we still have left. As long as they don't go overboard trying to convince me that their relics are better, I'll just sit here and laugh at the screen when they post as to how much better their 20+ year old amplifiers are than the modern day, JL Audio HD series.:laugh:


----------



## WRX/Z28 (Feb 21, 2008)

Niebur3 said:


> Class D started out with a rough beginning and it is just now (I would say, IMHO, starting with the JL HD's) coming into its own.
> 
> How many would use a Full Class D setup from pretty much any of the Class D amps made 10+ years ago?
> 
> ...


I guess i'm not remembering this rough begining. I remember them only being useful as sub channel amps due to switching noise that would be audible in the upper bands, but that was an early limitation of the design, and they were only sold as sub amps. I wouldn't say that that was a rough begining, more a limited use introduction. They did what they were advertised to do. The first slash series class D sub amps are around 10 years old at this point. They're still regarded as excellent amps. 

I'm really believing that these myths are perpetuated by people that do not want to learn, and find it easier to believe that more $, or "better equipment" trumps proper setup, planning, tuning, when the opposite is true. This isn't to say there is no merrit in equipment choosing, but far to many people seem to place all the weight on the gear itself. I've listened to dozens of systems that sounded excellent, all with completely different gear. 

I guess what i'm getting at is some people need to be more open, and listen instead of talking...


----------



## trojan fan (Nov 4, 2007)

PPI-ART COLLECTOR said:


> I should post a pic of her closet.


You might want to get her permission first, you know women also have privacy issues

It goes beyond my wife, my daughter is not far behind


----------



## Niebur3 (Jul 11, 2008)

WRX/Z28 said:


> I guess i'm not remembering this rough begining. I remember them only being useful as sub channel amps due to switching noise that would be audible in the upper bands, but that was an early limitation of the design, and they were only sold as sub amps. I wouldn't say that that was a rough begining, more a limited use introduction.


Lets see, that would be considered a "rough beginning" in my book considering where they are today. 

The initial Class D was a noisy sub only amp. That gets ingrained in their DNA from the onset and hard to get it back out. 

Oh, and the Slash series full range was Class A/B, while the sub amps were Class D and weren't full range. Do you think this aided in changing the perception? 

My point is, if they would have first brought out the JL HD's and were full range, I don't think any of the current preconceived notions would be there.


----------



## NucFusion (Nov 28, 2010)

Didn't Scott B run all jl hd 750/1's in the last highest scoring IASCA car?

I have to echo the post about making music and reproducing recorded music. I play guitar and bass and use both solid state amps and tube amps depending on the sound I'm looking for at the time. Tube amps are great for their responsiveness and offer the ability to overdrive them to get different amounts of distortion and clipping depending on the sound you are looking for. However, I will say that many of the higher end modeling solid state amps are getting very close to producing the same sounds without the added expense of pedals and extra gear to accomplish that sound.

That's all great for making noise, but when listening to recorded music, the last thing any audio purist would want is the sound being colored or distorted by overdriving the preamp signal or clipping the signal. I would guess its possible that people who are running amps lacking headroom could ultimately clipping the signal at high volumes and in that case, class a or ab would handle this more gracefully then class d amps.

22 years messing with car audio and owning many amps, mostly class ab, all I can say is that I am more than pleased running the jl audio xd amps


----------



## WRX/Z28 (Feb 21, 2008)

Niebur3 said:


> Lets see, that would be considered a "rough beginning" in my book considering where they are today.
> 
> The initial Class D was a noisy sub only amp. That gets ingrained in their DNA from the onset and hard to get it back out.
> 
> ...


I guess we'll have to agree to disagree. I think if they had came out with Class D and said it did everything, and then people found out that it didn't work for high freq. reproduction, that would be a rough start. This wasn't the case, the amps were said to be only for sub, then later they modified the design to work for everything by moving the switching noise above the human hearing range. That to me proves that the engineers producing these things just might have a handle on the technology, at least more so than your average forum user that claims they sound bad...


----------



## quality_sound (Dec 25, 2005)

I remember Infinity's full-range class D sounding pretty good. That was what, 1995?


----------



## Hoye0017 (Mar 23, 2010)

NucFusion said:


> 22 years messing with car audio and owning many amps, mostly class ab, all I can say is that I am more than pleased running the jl audio xd amps



That's weird. I would say its likely I've had as many amps as you have and I can't wait to replace my xd500/3.

I've heard a lot of high end systems including systems running various varieties of nice class D amps and Ive only heard one Class D system I liked. But I've heard plenty of A/B systems I like. 

There could be many reasons for this but it's the reality that keeps me prejudiced vs class D. I can't say that I started with a prejudice. I remember being excited to hear some of the first ones. And as I mentioned before, now that my brain is prejudiced, I may always hear the difference.

Take our mental blocks out of it and it's not necessarily D vs A/B but it's more amp vs amp and it also seems like there are only 2 class D full range amps to seriously consider VS many many A/B amps both old and new.


----------



## WRX/Z28 (Feb 21, 2008)

At this point there are dozens of class D rull range amplifiers to consider, and class a/b is really becoming the budget option for when you can't afford a full range class D.


----------



## BuickGN (May 29, 2009)

quality_sound said:


> I remember Infinity's full-range class D sounding pretty good. That was what, 1995?


I've got one of the Infinity Beta 300 amps but its not full range. I've run it on the AE subs that will play past 3khz and the amp I'm guessing won't even hit 500hz with no low pass. I had no idea there were full range class D back then.


----------



## BassnTruck (May 27, 2010)

Niebur3 said:


> Class D started out with a rough beginning and it is just now (I would say, IMHO, starting with the JL HD's) coming into its own.
> 
> How many would use a Full Class D setup from pretty much any of the Class D amps made 10+ years ago?
> 
> ...


I do. 

I have no complaints.


----------



## BassnTruck (May 27, 2010)

BuickGN said:


> I've got one of the Infinity Beta 300 amps but its not full range. I've run it on the AE subs that will play past 3khz and the amp I'm guessing won't even hit 500hz with no low pass. I had no idea there were full range class D back then.


You are correct in the beta 300s are rated 20-300Hz in the manual. The 100s and 50s are rated 20-20kHz.


----------



## Hoye0017 (Mar 23, 2010)

WRX/Z28 said:


> At this point there are dozens of class D rull range amplifiers to consider, and class a/b is really becoming the budget option for when you can't afford a full range class D.


Couldn't disagree more with that statement. The only 2 class d amps that are really considered for serious SQ are PDX and HD amps. 

I don't think I need to try to list the serious SQ A/B amps that are far from a budget compromise but a few that come to mind are Focal, Audison, and Brax.


----------



## quality_sound (Dec 25, 2005)

BuickGN said:


> I've got one of the Infinity Beta 300 amps but its not full range. I've run it on the AE subs that will play past 3khz and the amp I'm guessing won't even hit 500hz with no low pass. I had no idea there were full range class D back then.


It wasn't the Beta line. I am drawing a total blank on the model number but it was a mono, full-range amp that was about the size of a paperback.


----------



## LovesMusic (Mar 29, 2012)

WRX/Z28 said:


> At this point there are dozens of class D rull range amplifiers to consider, and class a/b is really becoming the budget option for when you can't afford a full range class D.


So far from the truth...
I believe high end Brax models are straight class A amps... designed most likely with a couple simple circuits Preamp Output, its only goal (as designated to class A)is to reproduce and amplify its direct preamp signal.

Someone else said it is not a matter of class vs class, it is every bit amp vs amp..
I agree with that statement..

WRX/Z28 I know you mentioned earlier about how JL markets their HD line as superior bc it is "better". This is not the case, Music is nothing but preference. Two people never hear the exact same thing the brain distinguishes that. 

Sure like mark said we can talk about an old computer being outdated, and technology is advancing and we are able to gain without sacrifice(which I do not believe based off my experiences) I mean from what I know and have learned in engineering everything has its sacrifices, however how about music being an emotion. envoking emotion is unique..
take this example: you have the choice of a new custom shop strat or a 1971 beat UP strat... Which do you choose?
For me..Id take the beat up strat, bet that b**** got more soul than me, for all I know its top pick up has a couple loose windings on it that dishes out some nice distortion at certain Fz...who knows but it sounds "better" to me 
maybe you like the new custom shop...


no right answer on this stuff...

Take it a step further...how about the amp that reproduces the artists music how the artist wants it interpretted? Maybe its supposed to soft clip at that bend on the b string...
Amps would sell like hot cakes if it was endorsed by a musicians musician..


I run HDs I love em everybit as the next guy theres just a but.. if I had it my way...Id take a well built class A-a/b anyday..

I mean I like to call that "what I like sound" warmth...pleasant distortion.. maybe thats another reason I tend to stay around paper cone drivers too...

I dk this is one of those endless wormhole discussions...to sum it up.. all get from point A to point B each take their own routes, the route I like you may not like in which case you will take a different route...


----------



## quality_sound (Dec 25, 2005)

Music is preference. Audio is science. Stop confusing the two and your system will sound better.


----------



## MarkZ (Dec 5, 2005)

quality_sound said:


> It wasn't the Beta line. I am drawing a total blank on the model number but it was a mono, full-range amp that was about the size of a paperback.


I also remember Infinity being among the first to market a full-range class D. I thought it was later in the 90s though.


----------



## MarkZ (Dec 5, 2005)

LovesMusic said:


> So far from the truth...
> I believe high end Brax models are straight class A amps... designed most likely with a couple simple circuits Preamp Output, its only goal (as designated to class A)is to reproduce and amplify its direct preamp signal.
> 
> Someone else said it is not a matter of class vs class, it is every bit amp vs amp..
> ...


I was with you until this last line. There absolutely _is_ a right answer. If it can be demonstrated that a class D amp can exhibit flawless distortion, noise, frequency response, and linearity, then I think we have our answer. That is, assuming the goal is to "reproduce and amplify" like you mentioned.

So, which one of you guys are going to test one of these JL amps?


----------



## Hanatsu (Nov 9, 2010)

How do I properly measure an amplifier btw? For power vs distortion I mean and not just THD.

Sent from my Samsung Galaxy 3 via Tapatalk.


----------



## WRX/Z28 (Feb 21, 2008)

Hoye0017 said:


> Couldn't disagree more with that statement. The only 2 class d amps that are really considered for serious SQ are PDX and HD amps.
> 
> I don't think I need to try to list the serious SQ A/B amps that are far from a budget compromise but a few that come to mind are Focal, Audison, and Brax.


Really considered for serious SQ by who? Many of us have used Clarion, Kenwood, Pioneer, Inifinity, Rockford Fosgate, just to name a few. There are dozens more out there, and they all perform with amazing similarity... :laugh:

Look at the bottom of any of their lines, they're always class A/B in their cheapest amps, because they're easier and cheaper to produce w/ less parts involved. 

So why would any amp company take the harder road if it made for worse SQ? 



LovesMusic said:


> So far from the truth...
> I believe high end Brax models are straight class A amps... designed most likely with a couple simple circuits Preamp Output, its only goal (as designated to class A)is to reproduce and amplify its direct preamp signal.


If you believe someone makes any kind of true Class A amp for the car, I have a bridge I'd like to sell you. 



LovesMusic said:


> Someone else said it is not a matter of class vs class, it is every bit amp vs amp..
> I agree with that statement..


What does that even mean? The whole discussion started in this thread was based on someone reitorating the idiotic notion that Class D amps are automatically inferior to Class A/B based on a flawed test he performed. 

How many different amps have you actually listened to under identical circumstances. My guess is 0. Even if you have attempted to, I doubt you've ever had a rig that could quickly switch between two properly set up amplifiers to try to hear a difference. 



LovesMusic said:


> WRX/Z28 I know you mentioned earlier about how JL markets their HD line as superior bc it is "better". This is not the case, Music is nothing but preference. Two people never hear the exact same thing the brain distinguishes that.


You're unfortunately making a true statement that does nothing to support your notion that JL doesn't market their HD amp as their top end line. What does music being a preference have to do with amplifiers that all sound the same? 

FWIW a quick quote straight from JL's HD amplifier page: "We invite you to sonically compare the HD amplifiers to any amplifier, at any price... We think you will quickly discover that all the old amplifier compromises have suddenly vanished." 



LovesMusic said:


> Sure like mark said we can talk about an old computer being outdated, and technology is advancing and we are able to gain without sacrifice(which I do not believe based off my experiences) I mean from what I know and have learned in engineering everything has its sacrifices, however how about music being an emotion. envoking emotion is unique..
> take this example: you have the choice of a new custom shop strat or a 1971 beat UP strat... Which do you choose?
> For me..Id take the beat up strat, bet that b**** got more soul than me, for all I know its top pick up has a couple loose windings on it that dishes out some nice distortion at certain Fz...who knows but it sounds "better" to me
> maybe you like the new custom shop...


You're back to music creation instead of reproduction. I thought MarkZ differentiated the two pretty well. 




LovesMusic said:


> no right answer on this stuff...
> 
> Take it a step further...how about the amp that reproduces the artists music how the artist wants it interpretted? Maybe its supposed to soft clip at that bend on the b string...
> Amps would sell like hot cakes if it was endorsed by a musicians musician..


So now driving an amp into clipping is the difference? You're all over the map.




LovesMusic said:


> I run HDs I love em everybit as the next guy theres just a but.. if I had it my way...Id take a well built class A-a/b anyday..


So why didn't you? What made you choose HD's if they're inferior?



LovesMusic said:


> I mean I like to call that "what I like sound" warmth...pleasant distortion.. maybe thats another reason I tend to stay around paper cone drivers too...


This is all nonsensical drivel that comes out of everyones mouth when they try to support the "amplifier sonic signature" argument.



LovesMusic said:


> I dk this is one of those endless wormhole discussions...to sum it up.. all get from point A to point B each take their own routes, the route I like you may not like in which case you will take a different route...





Guys, lets agree here that the point of an amplifier geared for music reproduction is to add nothing and take nothing from the sound. This I think we can pretty well agree is the goal when making an amplifier. To do otherwise would be silly, since there are so many different types of music, and so many different artists that play them, we could never create a sonic signature condusive too all of it, nor would I want any amplifier that tried. 

This being said, most also agree that when you go to A/B test amplifiers, that the difference is very subtle, and in the airyness, or the openness, or some other word that is an imposibility to quantify. Almost every time, it requires switching back and forth several times to "hear". 

That being almost the same story every time people try to "hear the difference between amps", the one thing I'd like to point out is this...

I could adjust your time alignment on your front speakers by .2 milliseconds, and take any person off the street and confirm there is an audible difference (they won't need golden ears). So what is the point of any minute difference in an amp if it can quickly be outdone by the smallest change in any control on your system, or for that matter any choice in loudspeaker that add's a night and day difference in sound, or even the same loud speaker who's angle was adjusted by 1 degree that would make a largely audible difference. 


All you guys that think you hear subtle differences in amps really need to think about this. 

If you think you hear huge differences in amps, you clearly performed the test wrong since even the most devout "amps sound different" supporters tend to believe the differences are small, and that it would come down to an instant a/b test to hear the difference...


----------



## hawkfan (May 1, 2006)

quality_sound said:


> It wasn't the Beta line. I am drawing a total blank on the model number but it was a mono, full-range amp that was about the size of a paperback.


It was an Xtant amp I believe. That was the first full range class D I remember. It was a one channel full range Class D amp which was unusual at the time. Heck, it's unusual now.


----------



## benny (Apr 7, 2008)

AS&S 1995, Fishman's Ranger with the first Infinity 2x75w digital amps.


----------



## SaturnSL1 (Jun 27, 2011)

Damn that's a smooth install!

The bug is biting...:uhoh:


----------



## Niebur3 (Jul 11, 2008)

WRX/Z28 said:


> Really considered for serious SQ by who? Many of us have used Clarion, Kenwood, Pioneer, Inifinity, Rockford Fosgate, just to name a few. There are dozens more out there, and they all perform with amazing similarity... :laugh:
> 
> Look at the bottom of any of their lines, they're always class A/B in their cheapest amps, because they're easier and cheaper to produce w/ less parts involved.
> 
> So why would any amp company take the harder road if it made for worse SQ?


ARC's lineup is exactly opposite of what you just stated, with their top line being Class A/B, then H, then D. (just playing devils advocate )


----------



## MarkZ (Dec 5, 2005)

Hanatsu said:


> How do I properly measure an amplifier btw? For power vs distortion I mean and not just THD.
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


An o-scope will probably do most of what you need, although you'll have to do most everything manually. If you want efficient, you probably want a software solution with a data acquisition card -- even a sound card would work, although your noise floor might be high. You need to knock the signal down to accommodate the voltage range of whatever input device you use. PM me if you want some recommendations.


----------



## WRX/Z28 (Feb 21, 2008)

Niebur3 said:


> ARC's lineup is exactly opposite of what you just stated, with their top line being Class A/B, then H, then D. (just playing devils advocate )


And where is ARC exactly on the map? They don't even design their own equipment, they simply rely on rebadging others. For every amp they make, JL and Alpine probably make 100. :laugh:


----------



## DAT (Oct 8, 2006)

WRX/Z28 said:


> And where is ARC exactly on the map? They don't even design their own equipment, they simply rely on rebadging others. For every amp they make, JL and Alpine probably make 100. :laugh:


Who is making the amps now? Still "uBuy" ?


----------



## WRX/Z28 (Feb 21, 2008)

DAT said:


> Who is making the amps now? Still "uBuy" ?


Last I heard, but I don't pay that much attention to remarketing companies...


----------



## Hanatsu (Nov 9, 2010)

MarkZ said:


> An o-scope will probably do most of what you need, although you'll have to do most everything manually. If you want efficient, you probably want a software solution with a data acquisition card -- even a sound card would work, although your noise floor might be high. You need to knock the signal down to accommodate the voltage range of whatever input device you use. PM me if you want some recommendations.


PM sent


----------



## Niebur3 (Jul 11, 2008)

WRX/Z28 said:


> For every amp they make, JL and Alpine probably make 100. :laugh:


I'm not sure what this statement proves? Since when does quantity automatically win over quality? And FWIW, Alpine probably makes 100 for every 1 JL makes, especially when you consider all the factory oem amps they produce. 

Oh, and Alpine's "best amp" (according to Alpine) MRV-F900 F#1 was a class A/B as well.


----------



## ErinH (Feb 14, 2007)

MarkZ said:


> An o-scope will probably do most of what you need, although you'll have to do most everything manually. If you want efficient, you probably want a software solution with a data acquisition card -- even a sound card would work, although your noise floor might be high. You need to knock the signal down to accommodate the voltage range of whatever input device you use. PM me if you want some recommendations.


my personal advice on doing this on a budget in a manner that is efficient and always straightforward (for repeatability) is: good luck.

the software is there. the issue is gain control of the output signal going in to the soundcards. you have to control each device's output in a different manner. harris labs makes a very nice variable attenuator but I found it was troublesome striking the sweet spot between frequency degradation and output voltage (ie: rolloff from having to pad down the voltage). It was at this point that I punted the whole project. If I had money, I'd just buy an AP unit and rock on.


----------



## avanti1960 (Sep 24, 2011)

CPPTG said:


> I think I will do the same. I will certainly level match the amps. I stated that in an earlier post, but I don't know if anyone read it or not.
> 
> However, I guess I should have also mentioned that I DID change the volume and the gains during my test, for my personal judgement. I just didn't think it was that dang important since I was stating I listened to both, and I prefer the A/B. Good lord, you would think some on here have stock in Class D amps. I stated which one I prefer, that's it. I didn't say you should like this one, or the one I tested or anything.


really, I hear you. you should read the thread in the "truth, myth and dogma" forum where you are told that "it isn't what you are hearing, it's what you want to hear that you hear" unfortunately what i "want" to hear isn't what i hear, so maybe i should not want to hear it instead? 

but seriously, i get your impressions and have heard similar characteristics when i compared my (2) amplifiers. even if you level matched to within 1/4 db and did ABX comparisons and hit on 10 out of 10 tries you would still be met with debate.


----------



## thehatedguy (May 4, 2007)

Wrx., I have a pure class a amp for the car and it uses, gasp, tubes.

No brax is class a...I have owned more than a few of them.


----------



## Hanatsu (Nov 9, 2010)

bikinpunk said:


> my personal advice on doing this on a budget in a manner that is efficient and always straightforward (for repeatability) is: good luck.
> 
> the software is there. the issue is gain control of the output signal going in to the soundcards. you have to control each device's output in a different manner. harris labs makes a very nice variable attenuator but I found it was troublesome striking the sweet spot between frequency degradation and output voltage (ie: rolloff from having to pad down the voltage). It was at this point that I punted the whole project. If I had money, I'd just buy an AP unit and rock on.


Well I guess there's a reason behind the lack of measurements on amps... Sounds like this is complicated at best. What is an AP-unit btw?


----------



## WRX/Z28 (Feb 21, 2008)

Niebur3 said:


> I'm not sure what this statement proves? Since when does quantity automatically win over quality? And FWIW, Alpine probably makes 100 for every 1 JL makes, especially when you consider all the factory oem amps they produce.
> 
> Oh, and Alpine's "best amp" (according to Alpine) MRV-F900 F#1 was a class A/B as well.




I wouldn't go that far with the #'s, but what it proves is a companies relevance. 


Where is this MRV-F900 now? Oh yeah, defunct. Didn't you even sell all of yours? So much for them being the best thing ever... 

Besides, IIRC it was right around the time the PDX's were introduced that F#1 was killed.


----------



## WRX/Z28 (Feb 21, 2008)

thehatedguy said:


> Wrx., I have a pure class a amp for the car and it uses, gasp, tubes.
> 
> No brax is class a...I have owned more than a few of them.


and it draws how much current and runs for how long before overheating? 

Who makes this amp? and don't say Milbert...


----------



## ChrisB (Jul 3, 2008)

Niebur3 said:


> IAnd FWIW, Alpine probably makes 100 for every 1 JL makes, especially when you consider all the factory oem amps they produce.


Interesting number considering 100% of the PDX amplifiers I owned had issues whereas 100% of the JL Audio amplifiers I owned worked perfectly fine. How's that for another statistic?:laugh:


----------



## benny (Apr 7, 2008)

WRX/Z28 said:


> and it draws how much current and runs for how long before overheating?
> 
> Who makes this amp? and don't say Milbert...


HSS FIDELITY car audio hi fi preamp final power loudspeaker for cars


----------



## Niebur3 (Jul 11, 2008)

WRX/Z28 said:


> I wouldn't go that far with the #'s, but what it proves is a companies relevance.
> 
> 
> Where is this MRV-F900 now? Oh yeah, defunct. Didn't you even sell all of yours? So much for them being the best thing ever...
> ...


Yep, you are right the $500 PDX's pieces of **** replaced the $3,500 F#1 amps . 

The F900 is defunct because it was $3,500. Not because of its technology. 

Now, I bought a lot of BNIB F#1 equipment with the sole purpose of selling. I said Alpine called them the best ever. With that being said, I have seen many JL HD amps for sale, that must mean they are junk as well. (Obviously, according to your philosophy, if you sell it and don't keep it, it is junk....Apparently all car audio is junk :laugh::laugh::laugh


----------



## MarkZ (Dec 5, 2005)

bikinpunk said:


> my personal advice on doing this on a budget in a manner that is efficient and always straightforward (for repeatability) is: good luck.
> 
> the software is there. the issue is gain control of the output signal going in to the soundcards. you have to control each device's output in a different manner. harris labs makes a very nice variable attenuator but I found it was troublesome striking the sweet spot between frequency degradation and output voltage (ie: rolloff from having to pad down the voltage). It was at this point that I punted the whole project. If I had money, I'd just buy an AP unit and rock on.


Frequency degradation? Why were you having rolloff?

You also didn't take my advice on the DAQ boards Erin.


----------



## MarkZ (Dec 5, 2005)

avanti1960 said:


> really, I hear you. you should read the thread in the "truth, myth and dogma" forum where you are told that "it isn't what you are hearing, it's what you want to hear that you hear" unfortunately what i "want" to hear isn't what i hear, so maybe i should not want to hear it instead?
> 
> but seriously, i get your impressions and have heard similar characteristics when i compared my (2) amplifiers. even if you level matched to within 1/4 db and did ABX comparisons and hit on 10 out of 10 tries you would still be met with debate.


Know what wouldn't be hit with debate? Objective data. I'd love to see someone identify the electrical differences between amp A and amp B after they hear a difference between them.

A thread that goes:

"I installed the new class D amp in my system, and it didn't sound as good as the class A/B I used to have. So I put them both on the bench and found..."

The person that does that would get a lot of respect from a lot of people. He would also provide more useful information to this forum than what most of us dumbasses provide.


----------



## thehatedguy (May 4, 2007)

WRX/Z28 said:


> and it draws how much current and runs for how long before overheating?
> 
> Who makes this amp? and don't say Milbert...


How does a tube amp over heat?


----------



## WRX/Z28 (Feb 21, 2008)

benny said:


> HSS FIDELITY car audio hi fi preamp final power loudspeaker for cars


:laugh:



Niebur3 said:


> Yep, you are right the $500 PDX's pieces of **** replaced the $3,500 F#1 amps .
> 
> The F900 is defunct because it was $3,500. Not because of its technology.
> 
> Now, I bought a lot of BNIB F#1 equipment with the sole purpose of selling. I said Alpine called them the best ever. With that being said, I have seen many JL HD amps for sale, that must mean they are junk as well. (Obviously, according to your philosophy, if you sell it and don't keep it, it is junk....Apparently all car audio is junk :laugh::laugh::laugh


If it's the magical amp that sounds better than anything else, why sell it? Why discontinue it? If you can prove it's undoubtedly better sounding than anything else, you should have a line of forum geeks beating down your door. Yet, why isn't everyone on this forum using exactly the same amp? 

JL amps are sold every day because they are easy to replace with another one that sounds the same. 

What did those F#1 amps do when listening to them that no other amp does? or that the PDX's (the current trouble free revisions) don't do? 

Someone answer that question please? What do these amps that sound so much better do differently? What do they add to the signal, or what don't they take away in comparison with other amps? Someone quantify it without using adjectives that are meaningless... 

Can someone show me what measurement changes from input to output, one amp vs. another, that shows the SQ gain in one amp, or SQ loss in another?


----------



## Hanatsu (Nov 9, 2010)

benny said:


> HSS FIDELITY car audio hi fi preamp final power loudspeaker for cars


Wow... I would never put such amps in my car. How are people supposed to do stealth installs with those beasts?! xD


----------



## Niebur3 (Jul 11, 2008)

WRX/Z28 said:


> If it's the magical amp that sounds better than anything else, why sell it? Why discontinue it? If you can prove it's undoubtedly better sounding than anything else, you should have a line of forum geeks beating down your door. Yet, why isn't everyone on this forum using exactly the same amp?
> 
> JL amps are sold every day because they are easy to replace with another one that sounds the same.
> 
> What did those F#1 amps do when listening to them that no other amp does? or that the PDX's (the current trouble free revisions) don't do?


You can read...correct??? IT WAS $3,500.00!!!! The market is not that big for a $3,500 amp even if it did make the music sound like angels were singing. Have Alpine release a $3,500 class D amp, it will fail also! Again, it's the price point, not the technology, which is what you eluded to up above.

I never said it sounded the best. (I keep typing this....reading comprehension is still a valuable tool) Alpine touted it as the best.

The point you are really failing about making regarding me selling the amps I bought specifically to sell, is just plain silly and doesn't make any sense. 

Oh, and your insinuation that Alpine replaced the F#1 series with the noisy initial PDX series (as a direct replacement) is laughable.

FWIW, I don't really have a problem with Class D amps and would run them in my car, but all you have to say is that they are transparent sounding, with great power in a small package. There are differences in amps. Amps do not all sound the same. It is because of topology? Probably not.


----------



## Hoye0017 (Mar 23, 2010)

Honestly WRX, you have made me lose interest in this thread. It's clear you think your Xd amps are a good as anything on the market. Please enjoy them. 

But your arguements are all over the place and contradict each other. You say in one statement that all amps sound the same and then use JL and alpine as examples of manufacturers choosing class D for their more expensive amps as proof that class D is the same as everything else. Then you use a quote from JL's HD amp marketing. Then ask why don't we all just use the same amp?

So using your logic and points of reference, why do JL and Alpine make different lines of class D amps if they are all the same? Are the Xd and HD the same in your eyes?

Why are there different amp companies period if they're all a commodity? We should all be buying acme brand.

Regardless, I'm done with this thread now. As soon as someone breaks out the "magic" concept, it's clear there will be no reasoning with them.


----------



## Richv72 (May 11, 2012)

We will see how many class d amps are still around after 30 yrs. I bet not many. For me class d signifies companies selling out and building overseas. Cheaply made and disposable.


----------



## SaturnSL1 (Jun 27, 2011)

I don't know why we get into long arguments over this stuff lol. If there is anything to take away from threads like this its that;

a) We all hear a little different, so we can't really agree anyway. And,
b) Amplifiers sound different.


----------



## SaturnSL1 (Jun 27, 2011)

Richv72 said:


> We will see how many class d amps are still around after 30 yrs. I bet not many. For me class d signifies companies selling out and building overseas. Cheaply made and disposable.


Absolutely.

There's more to these old relics than just style and nostalgia.


----------



## Hoye0017 (Mar 23, 2010)

Lastly, the reason they went the class d route to dominate their lines is the new industry term called "power density." Basically watts/cubic inch. Talk to a JL or alpine rep and see if they mention it. 

2 major concerns that car audio amps have always had for customers is size and efficiency/heat. 2 things that class D solves. Compare that to the home audio industry, where those two concerns don't exist. How is class D doing in that industry?


----------



## WRX/Z28 (Feb 21, 2008)

Niebur3 said:


> You can read...correct??? IT WAS $3,500.00!!!! The market is not that big for a $3,500 amp even if it did make the music sound like angels were singing. Have Alpine release a $3,500 class D amp, it will fail also! Again, it's the price point, not the technology, which is what you eluded to up above.


LOL! :laugh: So there aren't a line of customers that enjoy the finer things like Rolls Royce, Rollex, so on? These people don't apreciate music? You don't think there are a multitude of audio geeks on this forum alone that would pay that if it was unequivocally better? You are delusional if you believe that. People will pay any price if you can prove there is a benefit to be had. Some will pay the price if they simply believe you without proof. Those are typically the same people that believe $$$ = SQ. 




Niebur3 said:


> I never said it sounded the best. (I keep typing this....reading comprehension is still a valuable tool) Alpine touted it as the best.
> 
> The point you are really failing about making regarding me selling the amps I bought specifically to sell, is just plain silly and doesn't make any sense.
> 
> Oh, and your insinuation that Alpine replaced the F#1 series with the noisy initial PDX series (as a direct replacement) is laughable.


Amazing that your argument is so weak that you try changing it to my comprehension being the issue.

You insinuated that F#1 was better than their PDX's because it carried a higher price tag.  

You say it was discontinued because of cost. Ok, fine sure, we'll agree to disagree again. 

What else should I conclude? F#1 went away, and PDX came to market as Alpine's new top of the line, no? 


You shamelessly edited out my questions and avoided them altogether, so I'll repost them: 

*What did those F#1 amps do when listening to them that no other amp does? or that the PDX's (the current trouble free revisions) don't do? 

Someone answer that question please? What do these amps that sound so much better do differently? What do they add to the signal, or what don't they take away in comparison with other amps? Someone quantify it without using adjectives that are meaningless... 

Can someone show me what measurement changes from input to output, one amp vs. another, that shows the SQ gain in one amp, or SQ loss in another?*


----------



## WRX/Z28 (Feb 21, 2008)

Hoye0017 said:


> Lastly, the reason they went the class d route to dominate their lines is the new industry term called "power density." Basically watts/cubic inch. Talk to a JL or alpine rep and see if they mention it.
> 
> 2 major concerns that car audio amps have always had for customers is size and efficiency/heat. 2 things that class D solves. Compare that to the home audio industry, where those two concerns don't exist. How is class D doing in that industry?


Why create a new more expensive amp to solve a problem that doesn't exist? especially if it costs more to produce as well...


----------



## WRX/Z28 (Feb 21, 2008)

thehatedguy said:


> How does a tube amp over heat?


Via the transformer/power supply...


----------



## WRX/Z28 (Feb 21, 2008)

SaturnSL1 said:


> Absolutely.
> 
> There's more to these old relics than just style and nostalgia.


I own more of these relics that probably anyone else in this thread, and i'll be the first to say it's nostalgia and style... 

There's something fun about owning and utilizing old school equipment, but I'm not deluded into believing they outperform modern technology... especially based on my own a/b comparisons. What I found was when all else was equal, I couldn't hear a difference, and even when I tried to, if it was "maybe" there, it was so small, any other variable could have made a larger difference.


----------



## MarkZ (Dec 5, 2005)

Hoye0017 said:


> Lastly, the reason they went the class d route to dominate their lines is the new industry term called "power density." Basically watts/cubic inch. Talk to a JL or alpine rep and see if they mention it.
> 
> 2 major concerns that car audio amps have always had for customers is size and efficiency/heat. 2 things that class D solves. Compare that to the home audio industry, where those two concerns don't exist. How is class D doing in that industry?


It's actually doing pretty well there.

Class D is not new. It's only new to car audio because we get everything last.


----------



## SaturnSL1 (Jun 27, 2011)

WRX/Z28 said:


> I own more of these relics that probably anyone else in this thread, and i'll be the first to say it's nostalgia and style...
> 
> There's something fun about owning and utilizing old school equipment, but I'm not deluded into believing they outperform modern technology... especially based on my own a/b comparisons. What I found was when all else was equal, I couldn't hear a difference, and even when I tried to, if it was "maybe" there, it was so small, any other variable could have made a larger difference.


The difference is that these old amps have lasted a looooong time and will continue to. They were built like tanks. I can't begin to argue whether they out perform new technology because the only thing people care about is size and efficiency.

BTW, what makes your A/B tests any more believable than OPs? We all agree that we all hear differently so what makes you think you're on to something?


----------



## WRX/Z28 (Feb 21, 2008)

Hoye0017 said:


> Honestly WRX, you have made me lose interest in this thread. It's clear you think your Xd amps are a good as anything on the market. Please enjoy them.


I don't own any XD/HD or PDX amps.  In fact, I probably own more A/B amps than anything, but it's mostly out of nostalgia for old school equipment.
I'm not here to keep your interest anyway...



Hoye0017 said:


> But your arguements are all over the place and contradict each other. You say in one statement that all amps sound the same and then use JL and alpine as examples of manufacturers choosing class D for their more expensive amps as proof that class D is the same as everything else. Then you use a quote from JL's HD amp marketing. Then ask why don't we all just use the same amp?


Where did I contradict myself? Show me please? 
You missed most of my point. I was showing that Alpine and JL make Class D amps not because they sound better or worse, but because they offer a benefit over A/B. They in fact, sound the same. The benefit's are in efficiency, size, thermal management, and a few features like crossover capabilities and input capabilities. (features that have nothing to do with class a/b or d, simply included on a more expensive amp)

I was asking if amps all have varying levels of SQ, why hasn't anyone quanitified which one is the best, and why don't we all use that one? 



Hoye0017 said:


> So using your logic and points of reference, why do JL and Alpine make different lines of class D amps if they are all the same? Are the Xd and HD the same in your eyes?
> 
> Why are there different amp companies period if they're all a commodity? We should all be buying acme brand.
> 
> Regardless, I'm done with this thread now. As soon as someone breaks out the "magic" concept, it's clear there will be no reasoning with them.


Differing size, and features mainly. XD and HD have different input capabilities, different power ranges, different crossover capabilities. They sound the same when power/tuning are equal. 

You've contributed little to nothing to this thread anyway... no big loss if you leave.


----------



## Niebur3 (Jul 11, 2008)

WRX/Z28 said:


> LOL! :laugh: So there aren't a line of customers that enjoy the finer things like Rolls Royce, Rollex, so on? These people don't apreciate music? You don't think there are a multitude of audio geeks on this forum alone that would pay that if it was unequivocally better? You are delusional if you believe that. People will pay any price if you can prove there is a benefit to be had. Some will pay the price if they simply believe you without proof. Those are typically the same people that believe $$$ = SQ.


WOW. Ok, let me slow it down a bit for you....it takes more than a few that will pay (and have the means to pay) the Rolls Royce price to make it worth while to build and market a product for that price point. In this economy, you are really going to sit there and say topology is the reason they discontinued the F#1 amp and not price point? Why didn't they keep the speakers and HU's then? How many sq oriented HU's are currently on the market? People willing and able to pay prices for the "best" (proven or not proven) is far and few in between.



WRX/Z28 said:


> that your argument is so weak that you try changing it to my comprehension being the issue.
> 
> You insinuated that F#1 was better than their PDX's because it carried a higher price tag.


I did? When? There is that reading comprehension problem again. Dude, you really need some help. I never insinuated anything of the sort. Please show me where? 

I insinuated that statement as much as you insinuated pigs could fly. 





WRX/Z28 said:


> You say it was discontinued because of cost. Ok, fine sure, we'll agree to disagree again.


It's not about agreeing to disagree when you are just plain wrong. 




WRX/Z28 said:


> else should I conclude? F#1 went away, and PDX came to market as Alpine's new top of the line, no?


That's not a conclusion, that's an assumption and you know what happens when you assume. So, they marketed the PDX line as a replacement to the F#1 amps? They called them F#1 amps? 



WRX/Z28 said:


> shamelessly edited out my questions and avoided them altogether, so I'll repost them:
> 
> *What did those F#1 amps do when listening to them that no other amp does? or that the PDX's (the current trouble free revisions) don't do?
> 
> ...


I'm not the one sitting here saying Class A/B are better, so why do I need to answer your questions? I am just pointing out where your "conclusions" (assumptions) are wrong with many of the statements you are making.


----------



## hawkfan (May 1, 2006)

MarkZ said:


> *It's actually doing pretty well there.*
> Class D is not new. It's only new to car audio because we get everything last.


True. Class D Icepower amps are actually considered 'high end' in home theater and audio. I've enjoyed my class D 2 channel Onkyo A-9555 for years now with no issues.


----------



## trojan fan (Nov 4, 2007)

Richv72 said:


> We will see how many class d amps are still around after 30 yrs. I bet not many. For me class d signifies companies selling out and building overseas. Cheaply made and disposable.


Did you put any thought into your post :laugh:


Any 30 year old car amp is pretty much reduced to a paperweight with out some significant refurbishing

For any car amp manufacture, if you're not building a line of digital amp you're behind the times


----------



## ErinH (Feb 14, 2007)

MarkZ said:


> Frequency degradation? Why were you having rolloff?
> 
> You also didn't take my advice on the DAQ boards Erin.


rolloff due to increased resistance needed to attenuate the input signal. 

I didn't get the DAQ for a reason... no idea what it was anymore. 


If you can put together a computer based setup for $250-300 that can provide FR, HD, IMD, THD+N, Dynamic Output, etc and make it applicable to amplifier/pre-amp testing then I'm all ears. I can find products all day long... the hard part is making it work easily (ie: I don't have to take 30 minute to set up). That's part of the reason I stopped. The other part is that I just wanted to focus more on speakers because that's what really matters. But, seriously, if you can put something like this together then I'll buy it from you and kick you over $50 for your troubles. 

The one other thing I had an issue with was the fact that my computer based setup was limited in dynamic range which meant measuring equipment with high SNR (>100dB), in my opinion, somewhat meaningless.


----------



## WRX/Z28 (Feb 21, 2008)

SaturnSL1 said:


> The difference is that these old amps have lasted a looooong time and will continue to. They were built like tanks. I can't begin to argue whether they out perform new technology because the only thing people care about is size and efficiency.
> 
> BTW, what makes your A/B tests any more believable than OPs? We all agree that we all hear differently so what makes you think you're on to something?


Probably the fact that I made some attempt to level the playing field by matching the output of both amps, and he admittedly didn't. 

For those eluding to who my dog is in this fight. 

FWIW, my nostalgia has put me to this point:































and so on...


----------



## LovesMusic (Mar 29, 2012)

MarkZ said:


> I was with you until this last line. There absolutely _is_ a right answer. If it can be demonstrated that a class D amp can exhibit flawless distortion, noise, frequency response, and linearity, then I think we have our answer. That is, assuming the goal is to "reproduce and amplify" like you mentioned.



Well at least someone followed where I was going with it, I tend to see an all encompassing side of a final product, if class d can exhibit those features you mentioned then sure that is our answer, but thats merely a hypothesis of future work...

quality_sounds..
"Audio is science and my system will sound better when I realize that... ?" 
really? thanks
So your the guy that would tell me 8 cylinders is better than 4? Or a turbo is better then a supercharger, or Q-16 is better then rocket fuel110(ethanal)..
Your right im into cars, audio not so much... 


When is too much circuitry too much tho? something has to be lost, when I look at a basic circuit diagram of a class A amp, I see it, as being the ultimate simple amplification, and if others are able to circuit analyze in this fashion (very basic) well have a few more believers, nothing more than wire and gain...



WRX told me how many amps Ive listened to back to back, Id say a couple, thanks crutchfield, I dare not make the mistake of going to one of these local NJ shops to hear how bad such and such is and how I should get this amp from you...


JL markets their top teir line as their top tier based on price. It has nothing to do with me telling you I like the sound of their less expensive slash amp to your choice of the HD, heres how it all doesnt matter...bc what I hear may not be what you hear.

Now about the 2 guitar ex I was trying to explain....
sure markz differenciated between creating and reproduction but your not following...like I said about the pickup sending some distortion on a nice b string bend well that guitar is used bc IT DOES DISTORT there..If the artist didnt want it to be reproduced THAT guitar wouldnt be used... Theres a reason for claptons Blackie and every other artist who uses certain guitars for decades, these guys distort on stage in the studio and expect it to be captured in the reproduction...Its what I call personality and you call sonic signature.

WRX/Z28-"This is all nonsensical drivel that comes out of everyones mouth when they try to support the "amplifier sonic signature" argument."

thats kind of offensive, Im sure mr hendrix or jeff beck or just about any musician you said this too would gladly place their instrument up your ass and tell you to have a listen...

you hear it? lol im sorry but seriously I mean you can change the tone just by hybrid picking instead of just a pick, and im sure one amp is going to capture and reproduce that picking better then another. What it sacrifices from one side of its circuit it gains in another no pun intended..

quite honestly I bought the HD amps for their size and I tend to like JL power... Nothings perfect in a car audio environment and the "class D" inferior power i have will not be the weakest link...



But moving to the discussion of Alpines best audio amp and what not, like neibur said marketing, price point, economy all come to mind when someone tells me it failed... How about the McClaren F1 that was built in the 90s and discontinued and it took konesieg or whatever almost 20 years to build its competetion and even then id take the F1 still, 


WRX/Z28- "I was asking if amps all have varying levels of SQ, why hasn't anyone quanitified which one is the best, and why don't we all use that one?" 


BC audio is personal preference...!!!! the same reason we all use different speakers and different processors, to quanitify which one is best is flat out WRONG that is why...
Quantum physics...


Markz we take 2 of the same amps, listen to them and then individually o scope each resistor, diode, and transistor etc and tolerance them. we then take a basic deviation from our results to determine the fairy dust between amps...This is only to begin such an experiment in hopes of objectional data


----------



## WRX/Z28 (Feb 21, 2008)

Niebur3 said:


> WOW. Ok, let me slow it down a bit for you....it takes more than a few that will pay (and have the means to pay) the Rolls Royce price to make it worth while to build and market a product for that price point. In this economy, you are really going to sit there and say topology is the reason they discontinued the F#1 amp and not price point? Why didn't they keep the speakers and HU's then? How many sq oriented HU's are currently on the market? People willing and able to pay prices for the "best" (proven or not proven) is far and few in between.




Same amount as Alpine charging $3500 for an amp. Do you think it cost them anywhere near $3500 to produce them? No, they factored in how many they were likely to sell. Thanks for the slow down though... whoooh.



Niebur3 said:


> I did? When? There is that reading comprehension problem again. Dude, you really need some help. I never insinuated anything of the sort. Please show me where?
> 
> I insinuated that statement as much as you insinuated pigs could fly.



LOL, ok man. :laugh: I'm not going back through your posts, simply not worth my time. You can re-read them yourself. 






Niebur3 said:


> It's not about agreeing to disagree when you are just plain wrong.



What exactly am I wrong about?






Niebur3 said:


> That's not a conclusion, that's an assumption and you know what happens when you assume. So, they marketed the PDX line as a replacement to the F#1 amps? They called them F#1 amps?



They were the top of the line that came out around the time the F#1 went away. That makes them the top of the line at that point. What else could an alpine fan purchase for a top of the line amp?




Niebur3 said:


> I'm not the one sitting here saying Class A/B are better, so why do I need to answer your questions? I am just pointing out where your "conclusions" (assumptions) are wrong with many of the statements you are making.


So what was your point again? Now my comprehension is suspect... i'm missing what your argument is, other than that i'm wrong... and what exactly am I wrong about?


----------



## MarkZ (Dec 5, 2005)

bikinpunk said:


> rolloff due to increased resistance needed to attenuate the input signal.
> 
> I didn't get the DAQ for a reason... no idea what it was anymore.


I think it was the software compatibility issue... But I thought there was some NI support under virtins? Isn't that what you went with?




> If you can put together a computer based setup for $250-300 that can provide FR, HD, IMD, THD+N, Dynamic Output, etc and make it applicable to amplifier/pre-amp testing then I'm all ears. I can find products all day long... the hard part is making it work easily (ie: I don't have to take 30 minute to set up). That's part of the reason I stopped. The other part is that I just wanted to focus more on speakers because that's what really matters. But, seriously, if you can put something like this together then I'll buy it from you and kick you over $50 for your troubles.


Nevermind the $50. But it might be time to revive that other thread if you're interested in still doing this. My offer still stands as far as writing the software you need. I think once the software is worked out, it would be about 100x easier than speaker testing.


----------



## SaturnSL1 (Jun 27, 2011)

This is completely off topic, but WRX, why is there a "boyfriend pillow" on your night stand?


----------



## WRX/Z28 (Feb 21, 2008)

SaturnSL1 said:


> This is completely off topic, but WRX, why is there a "boyfriend pillow" on your night stand?


LOL, cause my fiance like's to cuddle when she sleeps, and I don't. I bought that as a gag gift for her, but she actually likes it. Good eye!


----------



## thehatedguy (May 4, 2007)

I love the old stuff. My jl hd amps remind me most of my old brax amps though.


----------



## SaturnSL1 (Jun 27, 2011)

WRX/Z28 said:


> LOL, cause my fiance like's to cuddle when she sleeps, and I don't. I bought that as a gag gift for her, but she actually likes it. Good eye!


Ok, that's what I was thinking lol 

If I had that pillow I'd show off every new amp I buy with it holding it lovingly lol.


----------



## WRX/Z28 (Feb 21, 2008)

Here is my point, that probably got lost in the mindless "you're wrong, no you're wrong" nonsense of the last 3 pages. 


*Amps sound the same when power is the same.* Even in the event that i'm wrong about this, the difference is so minute, that I (as well as many many others) haven't been able to detect it through the huge pile of different equipment that I own when leveling the playing field. 

Even if this is the case, the difference is so minute that adjusting time alignment, one eq band, gain, crossover points, drivers, positioning of drivers, sound deadening, environment, # of people in the car... all of these can have a greater effect on our sound system than any amp change ever could. 

Everyone that's stressing the virtue's and pitfalls of class D vs. Class A/B, and the virtue's of amp company A vs. the pitfalls of amp company B, are investing far too much time in far to trivial of a piece of the car audio puzzle. 

If you guys arguing that amps all sound different spent half as much time reading about proper tuning, setup, T/A, phase, early reflections, diffraction, positioning and so on, as you do arguing about amps sounding different, you might actually get your sound system to the point where it sounded good regardless of what amp was in there...


----------



## Niebur3 (Jul 11, 2008)

WRX/Z28 said:


> Same amount as Alpine charging $3500 for an amp. Do you think it cost them anywhere near $3500 to produce them? No, they factored in how many they were likely to sell. Thanks for the slow down though... whoooh.


You can't make a profit if you don't sell any amps genius. 




WRX/Z28 said:


> , ok man. :laugh: I'm not going back through your posts, simply not worth my time. You can re-read them yourself.


I have and I never insinuated the F#1 was better due to its $3,500 price tag. Again, please show me where I did or else you have reading comprehension issues (or simply just make **** up). 




WRX/Z28 said:


> exactly am I wrong about?


It's like talking to an infant. YOU ARE WRONG ABOUT WHY THE F#1 WAS DISCONTINUED!




WRX/Z28 said:


> They were the top of the line that came out around the time the F#1 went away. That makes them the top of the line at that point. What else could an alpine fan purchase for a top of the line amp?


Wrong again Skippy. The F#1 was it's own line, never intermixed with Alpines standard line (just like Pioneer Stage4). 

And what made the PDX Amp, Alpine's "top of the line" amp? Marketing and price point (same as what made the F#1 top of the line)!


----------



## WRX/Z28 (Feb 21, 2008)

SaturnSL1 said:


> Ok, that's what I was thinking lol
> 
> If I had that pillow I'd show off every new amp I buy with it holding it lovingly lol.



Not a bad idea... lol. Maybe that'll be my new "proof it's mine" in any For Sale thread...


----------



## Niebur3 (Jul 11, 2008)

WRX/Z28 said:


> Here is my point, that probably got lost in the mindless "you're wrong, no you're wrong" nonsense of the last 3 pages.
> 
> 
> *Amps sound the same when power is the same.* Even in the event that i'm wrong about this, the difference is so minute, that I (as well as many many others) haven't been able to detect it through the huge pile of different equipment that I own when leveling the playing field.
> ...


Finally, an intelligent post free from all the "conclusions", assumptions, and all the other BS you were trying to use to prove your point.

I agree with this post 100%


----------



## SaturnSL1 (Jun 27, 2011)

WRX/Z28 said:


> Not a bad idea... lol. Maybe that'll be my new "proof it's mine" in any For Sale thread...


Exactly what I was thinking lol


----------



## WRX/Z28 (Feb 21, 2008)

Niebur3 said:


> You can't make a profit if you don't sell any amps genius.


So you're saying Alpine never sold 1? Cause I know this is not the case




Niebur3 said:


> I have and I never insinuated the F#1 was better due to its $3,500 price tag. Again, please show me where I did or else you have reading comprehension issues (or simply just make **** up).


Oh god... When I said PDX was their top end, and positioned over their MRV and MRX amps, you pulled out the F#1 card. Was that not insinuating it was better even though they barely ran concurrently? Where the hell is the facepalm smiley?





Niebur3 said:


> It's like talking to an infant. YOU ARE WRONG ABOUT WHY THE F#1 WAS DISCONTINUED!


And you are the guy at alpine that made the decision to pull the plug? otherwise you should add "in my opinion", since your statement isn't exactly fact. 




Niebur3 said:


> Wrong again Skippy. The F#1 was it's own line, never intermixed with Alpines standard line (just like Pioneer Stage4).
> 
> And what made the PDX Amp, Alpine's "top of the line" amp? Marketing and price point (same as what made the F#1 top of the line)!


huh? now your reading comprehension is suspect...


----------



## LovesMusic (Mar 29, 2012)

WRX/Z28 said:


> Here is my point, that probably got lost in the mindless "you're wrong, no you're wrong" nonsense of the last 3 pages.
> 
> 
> *Amps sound the same when power is the same.* Even in the event that i'm wrong about this, the difference is so minute, that I (as well as many many others) haven't been able to detect it through the huge pile of different equipment that I own when leveling the playing field.
> ...


Shouldve been your first post I can agree 100%, I still prefer class a/b


----------



## WRX/Z28 (Feb 21, 2008)

FWIW, this was in post #97 which basically says the same thing. 



WRX/Z28 said:


> Guys, lets agree here that the point of an amplifier geared for music reproduction is to add nothing and take nothing from the sound. This I think we can pretty well agree is the goal when making an amplifier. To do otherwise would be silly, since there are so many different types of music, and so many different artists that play them, we could never create a sonic signature condusive too all of it, nor would I want any amplifier that tried.
> 
> This being said, most also agree that when you go to A/B test amplifiers, that the difference is very subtle, and in the airyness, or the openness, or some other word that is an imposibility to quantify. Almost every time, it requires switching back and forth several times to "hear".
> 
> ...


This just got completely ignored.


----------



## Richv72 (May 11, 2012)

trojan fan said:


> Did you put any thought into your post :laugh:
> 
> 
> Any 30 year old car amp is pretty much reduced to a paperweight with out some significant refurbishing
> ...


Get an old zapco amp 30 yrs old and chances are its still working without anything being done to it. Not even caps replaced.


----------



## WRX/Z28 (Feb 21, 2008)

Richv72 said:


> Get an old zapco amp 30 yrs old and chances are its still working without anything being done to it. Not even caps replaced.


Not for very long. Most electronic components have a finite life span. Agree'd that some last longer than others, but stating that Class D will not last as long without any proof is pointless...


----------



## Hanatsu (Nov 9, 2010)

I concluded this way back: Want different/(better) sound from your system? Buy a DSP, change speakers and/or change/improve the install.


----------



## sqshoestring (Jun 19, 2007)

Hoye0017 said:


> Lastly, the reason they went the class d route to dominate their lines is the new industry term called "power density." Basically watts/cubic inch. Talk to a JL or alpine rep and see if they mention it.
> 
> 2 major concerns that car audio amps have always had for customers is size and efficiency/heat. 2 things that class D solves. Compare that to the home audio industry, where those two concerns don't exist. How is class D doing in that industry?





MarkZ said:


> It's actually doing pretty well there.
> 
> Class D is not new. It's only new to car audio because we get everything last.


And do they get it last. Much of my experience with class D is with home receivers. They went class D long ago with various results. You could usually crank them up near clipping and it was easy to tell. However today they are much better. Today even cheap items are using class D chips for amps.

There have always been crappy car amps, some people collect today I used and they sucked. Just the same if I pull out my HK or old PPI (if the transistors have not unsoldered themselves again) or old SS or old alpine amp...etc...I know what I got, I know it will perform as expected. It may be larger and warmer but it works fine so why not use it. Up to around 100rms it does not matter that much, but I gave up owning larger class AB some time ago for heat and power issues. The only reason I have this kappa Z is because I scored a fantastic deal on it, and having a 125rmsx4 this small I can use in many situations. But I built my amp rack to fit a couple huge HK amps if that tells you anything....only for non sub use of course.

Come on, some amps do sound different. It may be how they clip, it may be noise floor or resistance to noise in your install, who knows why. No the difference is rarely that much though noise can be very annoying. Then you have quality and power and heat differences, physical size/shape, cost, possibility of theft....all kinds of reasons to use a different amp for a given install.


----------



## SaturnSL1 (Jun 27, 2011)

WRX/Z28 said:


> Not for very long. Most electronic components have a finite life span. Agree'd that some last longer than others, but stating that Class D will not last as long without any proof is pointless...


Only time will tell. Even my ****tiest flea market amps from the early 90s and late 80s are in working order with all original parts. However, all of my dud amps are newer than 2000 except for one Kenwood and an old ass Lanzar.


----------



## MarkZ (Dec 5, 2005)

That might be the first time I've heard someone put ****ty flea market amps up on a pedestal.


----------



## Richv72 (May 11, 2012)

A working flea market amp from the 80's does in fact sound better than a non working class d amp from 2005.


----------



## SaturnSL1 (Jun 27, 2011)

MarkZ said:


> That might be the first time I've heard someone put ****ty flea market amps up on a pedestal.


Some of the junk is underrated and overlooked in my opinion


----------



## Horsemanwill (Jun 1, 2008)

bbfoto said:


> Hey Sound Suggestions,
> 
> It would be awesome to have a World Champion SQ Car at IASCA/MECA/USACi Finals that is set up with level-matched Class A-A/B vs. Class D amplifiers with everything else in the system the same, and all amplifiers hidden from view. Then have 4 or 5 judges score the car at least one day apart using an unmarked/random switch to choose between the amplifier setups. Now that would be interesting!


this statement there made me think. if someone took 3 same cars. make, model, year: everything. then installed identical systems. hu, speakers, placement: everything: but with the amps being the difference in the signal chain. then tuned everything properly. gain structure etc. then go to the finals and let the judges sit in the car without seeing the amps how would that go?


----------



## LovesMusic (Mar 29, 2012)

Markz- I think we indeed lost something designing into class d, whether we are at that point of seeing where it fails is yet to be seen...

but il have to agree with RichV I dont see any class d with standing the abuse of "time" too many components what happened to KISS?

Its like rocket science, how intrinsict do you want your lift, oh you want some sort of ramping lift(the thoughts there)...but that also plays to more that can potentially go wrong, at some point. 



and throughout this whole discussion no one seems to think that the theory of relativity does not play directly with this whole thread... 

All working amps are pretty cool in my book...


----------



## MarkZ (Dec 5, 2005)

LovesMusic said:


> Markz- I think we indeed lost something designing into class d, whether we are at that point of seeing where it fails is yet to be seen...
> 
> but il have to agree with RichV I dont see any class d with standing the abuse of "time" too many components what happened to KISS?



What did we lose with class D? Why are you making the assumption that there's something lost? You haven't been specific about this.

The reason some amps are more complex than other amps isn't because amp designers just felt like putting more components in there for fun. They do it because adding circuits to a very simple design yields improvements. I mentioned earlier that the lowest distortion designs tend to be the ones with the highest parts counts. 

For example, how do you improve noise performance? Well, you add buffer circuits between the voltage rails and the signal path to improve PSRR. Each buffer circuit is (at least) two more transistors per channel, and you have at least two points where the signal path comes in "contact" with the power supply. Cool. 

Ok, how do you improve distortion performance? One way is to upgrade a simple input transconductance stage with a differential stage, which adds to the complexity of the input by quite a bit. Want it to be improved even more? Use a push-pull mirror input stage which literally _doubles_ part count. This is awesome, but now we have even more buffer circuits to add to maintain our improved noise performance!

Ok great, we've addressed some small signal forms of distortion, but we still have to worry about output stage distortion. We want to avoid crossover distortion. Ok, let's add a bias circuit that bumps up the bias to make the amp operate in A/B. Crossover distortion gone!

Well, almost. We can improve output distortion even more by incorporating a global negative feedback circuit to tap into that input differential circuit that we added earlier. Crossover distortion is even lower now!

Hmmm... this amp is starting to perform great! But how come the improvements we made start to disappear when the temperature changes? Let's accurately control the bias so that it adjusts itself with temperature. Well, that requires a temperature sensor, a bias adjustment circuit, and some calibration circuitry. Now we're in a self-adjusting bias class B. Lots of parts!

All of these transistor circuits are great, but no transistor behaves perfectly, especially at high frequencies. Each of those should have a local NFB circuit to compensate for that. Even better performance now!

But what about temperature stability? Don't we want this amp to know when it's getting too hot and shut itself down? Let's add a thermal circuit.

Now how about oscillations? We've got feedback circuits up the wazoo... that can't be good! We don't want reactive loads to make the amp self-destruct! So let's add an output zobel circuit. And some overcurrent circuitry for good measure.

This is great, but the power supply is humming along at max output all the damned time. Well, let's make it only draw current when the music is strong. It will sense how much voltage it has stored in its capacitors, and draw extra current when the reserve starts getting low. Awesome! But this is going to mean we yank out the simple power supply and replace it with a much more complex PWM switchmode supply, with all its associated protection circuitry.

What the hell???? What happened to our KISS circuit?? Well, you said you wanted a low distortion amp that was stable. We added circuits to do exactly that.

Now, if we can only figure out a way to take our low noise, low distortion, ultra-stable amp, and make it 80% efficient instead of 50% efficient...


----------



## LovesMusic (Mar 29, 2012)

MarkZ said:


> What did we lose with class D? Why are you making the assumption that there's something lost? You haven't been specific about this.
> 
> The reason some amps are more complex than other amps isn't because amp designers just felt like putting more components in there for fun. They do it because adding circuits to a very simple design yields improvements. I mentioned earlier that the lowest distortion designs tend to be the ones with the highest parts counts.
> 
> ...




Your a smart man, Unfortunately I am unable to analyze such a complex circuit I only have basic lab and o-scope training in basic circuit components ending in class A design amplification lol...:blush: sorry.

So when I say "something" I am generalizing in almost all aspects of engineering, Iron is a good example, and its carbon content as the basis of the many forms of steel. A supercharger to a turbo...these are some of the examples of such sacrifices I envision of happening...

Im a numbers kind of guy, show me and my mouth is shut. For all I know you maybe right, in which case there will be no need for this discussion.


----------



## thehatedguy (May 4, 2007)

Why are the oldies in such good shape? Because they were so freaking expensive when they were new that people took real good care of them. They are expensive now because nostalgia is expensive. How many classified posts do you see that are "rare old school" and expensive as hell for what was junk when it was new?

No the new stuff wont be around because they are disposable.


----------



## sqshoestring (Jun 19, 2007)

A class D amp is not much different than a class AB, even though I can't design an amp (at least not without some study). All you are doing is driving the outputs with a PWM audio signal instead of a form of the audio signal itself. So the outputs turn on/off very fast (faster than your highest Hz produced) and some filters in the output smooth out any residual modulation. You make the power supply a little different because you need more voltage than the rail to drive the outputs that hard. You use different outputs that are better at that. The feedback circuit is different since it is PWM and not straight audio, though there are different ways of doing it. Otherwise you have a similar power supply section, pre-amp section, and those changes to the output section. You do this because it is way more efficient to drive high speed transistors this way than to modulate them with audio. Most cordless drills PWM the variable speed, likely all do.

Hybrids take a class AB and put controls on the power supply to cut the rails down when not needed. The difference in rail voltage and output determines much of the loss. So at low output you lose a lot (which is offset by the fact that you are at low power anyway, but efficiency is efficiency). So the PS mimics the output voltage that need be sent to your speakers and cuts this loss. I've fixed a lot of amps, class AB are pretty simple in most cases building one is just a matter of everything balancing out. People on diyaudio are building amps all the time. Newer amps will still be harder to repair mostly because of SMD the stuff is so small and harder to follow the circuits...and yeah who is going to fix them. I only fix amps that are older or fix to pay for older amp I want lol. Most amps are not worth fixing far as cost. IIRC a LP 2002 was about $350 in the late 80s, punch that into a inflation calculator as well as taking a look at average incomes of younger people at the time.


----------



## LovesMusic (Mar 29, 2012)

Hatedguy speaks the truth of it...


anyway, I understand the use of push pull transistor technology as it is used in home audio. From a car audio aspect now that i think about what you said and how we layer circuits with circuits to compensate noise rejection etc. 

but "Markz" from a schematics perception why couldn't we compensate layout wise and using certain grounds in a simplistic approach. Why couldn't we set a nominal operating temperature in which the user will construct. Does saving amperage for the gain structure net. 
More parts = more money = higher production costs = cheaper parts = reliability issues = larger tolerances = etc or less parts = higher material investment = reliability = etc..

I dont know any of the answers...
I just enjoy learning and bullshitn :laugh:


----------



## MarkZ (Dec 5, 2005)

I don't know what you mean when you say "compensate layout wise". Like I mentioned, those added circuits DO something specific. They're there to try to achieve something that the simplest form of an amplifier circuit just can't accomplish. You build the simple circuit and then analyze in what areas it falls short and _why_. When you figure out the "why", you can then design a circuit that gets around that.


----------



## NucFusion (Nov 28, 2010)

The major benefit of these hybrid rail and class d switching amps has to be the amount of power that can be produced from a stock charging system. They also require minimal cooling, so they can easily fit in any vehicle. This is the future of audio and the companies ahead of the curve will be at a major advantage, assuming they produce a competent product. Home audio has been making great full range class d amps for some time now. 

I still love the old school amps, but its honestly more nastalgia than anything. I think there was just something fun about running amps rated for 20 watts, knowing they were putting out closer to 3 times as much power. What I don't miss is the wall of heaters and the thermal shut offs after 2 hours of loud music on a 100 degree day.

Maybe I destroyed my ears years ago, but I just can't hear enough difference between any amp class for audio amplification to matter. I recently went to my local audio shop where I've dealt with the same guys for 12 years now and they wanted to show off the new audison voce amps that run class a, ab and d all in one 5 channel amp. We played all kinds of music and used the same speakers, head unit and switched back and forth between the jl xd,hd and audison voce and sr amps, and other then a power difference, I pretty much thought they sounded similar. I even joked that I wouldn't do that with any other customers if thet want them to shell out the $1500 for the audison amps.


----------



## trojan fan (Nov 4, 2007)

SaturnSL1 said:


> Even my ****tiest flea market amps from the early 90s and late 80s are in working order with all original parts.



Hoarder!!!!!


----------



## Sound Suggestions (Dec 5, 2010)

Pay particular attention to the top portion of page 2 (description of class D sound) and also the bottom half of page 2 (for non-believers)

NAD T 787 A/V Receiver | Home Theater

Check mate 

Unless you guys get paid for your editorial prowess by a renowned magazine.


----------



## Horsemanwill (Jun 1, 2008)

can u really judge car audio amps against home audio ones? i mean if you could wouldn't they just convert home audio ones to 12v power supplies and put them in cars?


----------



## WRX/Z28 (Feb 21, 2008)

Sound Suggestions said:


> Pay particular attention to the top portion of page 2 (description of class D sound) and also the bottom half of page 2 (for non-believers)
> 
> NAD T 787 A/V Receiver | Home Theater
> 
> ...


Oh ****, you got us. Skeletel sounding. From the only expert we can't posibly dispute... a magazine editor! on an INTERNET MAGAZINE! Thank god that you found this, I was just about to go enjoy listening to some music on a class D amp... it could have been a tragedy! 

:thinking2:


----------



## Sound Suggestions (Dec 5, 2010)

Horsemanwill said:


> can u really judge car audio amps against home audio ones? i mean if you could wouldn't they just convert home audio ones to 12v power supplies and put them in cars?


Of course not, but just trying to prove a point that different amplifiers class will have a different sound...

Don't get me wrong, I do believe with today's technology advancement it is only a matter of time before a Class D will be manufactured to sound just as good if not better than the A/B, it was only a few years ago that a Class D was too noisy and could only be used as subwoofer amplifier, they do have come a long way since then!


----------



## IDGAF (Dec 27, 2009)

Sound Suggestions said:


> This guy gets paid for his editorials by (insert this month's item).
> 
> Check mate


Fixed.


----------



## Sound Suggestions (Dec 5, 2010)

WRX/Z28 said:


> Oh ****, you got us. Skeletel sounding. From the only expert we can't posibly dispute... a magazine editor! on an INTERNET MAGAZINE! Thank god that you found this, I was just about to go enjoy listening to some music on a class D amp... it could have been a tragedy!
> 
> :thinking2:


^
You really should have done your homework before posting this reply, or taken your time before posting...Home Theater Magazine is a published (printed magazine ) that has been in circulation for quite some time...yes they do offer a digital copy through the Internet (as all other publishers...If they want to stay in business )

Their editors are well respected and get paid (I would assume a decent wage also)...how many magazine have you sold? 

The point of this debate is just to prove that amplifiers will have their own signature sound, and yes they will sound different from one another

Again don't get me wrong you can go listen to your music on your class D and enjoy it fully...I'm not here to say (or push my belief on to you) bottom line you like one I like the other, just posting here so that the newer generation of car audio geeks get a little guidance, I don't believe that it's as easy as one size fits all


----------



## Sound Suggestions (Dec 5, 2010)

IDGAF said:


> Fixed.


LOL, yes editorials are paid for, but not always reviewed favorably


----------



## WRX/Z28 (Feb 21, 2008)

Sound Suggestions said:


> ^
> You really should have done your homework before posting this reply, or taken your time before posting...Home Theater Magazine is a published (printed magazine ) that has been in circulation for quite some time...yes they do offer a digital copy through the Internet (as all other publishers...If they want to stay in business )
> 
> Their editors are well respected and get paid (I would assume a decent wage also)...how many magazine have you sold?
> ...


:laugh:

What did this prove, other than that a biased magazine editor believes he hears a difference? 

The problem is that your guidance is flawed, and based on 2nd hand opinion instead of facts. Thank god the current generation of car audio geeks have other more knowledgeable people that you (and myself) to listen to. 

This reminds me of that recent commercial with the girl that believed everything she heard on the internet and wandered off with her "french supermodel" boyfriend...


----------



## RNBRAD (Oct 30, 2012)

Start on 2nd page under "statuesque". Interesting take.
Pioneer Elite SC-68 A/V Receiver Page 2 | Home Theater


----------



## NucFusion (Nov 28, 2010)

NAD T 787 A/V Receiver | Home Theater 

So, I have a superior sounding meaty amp with my greatest known to man speakers (which I assume are set up for perfect imagining)...they all produce a very distinguishable tone that I find more pleasing then other comparable amps...so why not just listen to them as is. The first thing he does is runs the auto dsp, which changes the speaker distances from what they are, but also changes the tonal characteristics of the set up....so, does this system sound better compared to a class d amp with the same dsp settings applied? Guess we will never know, so we have to take his intro blurb as the proof.


----------



## WRX/Z28 (Feb 21, 2008)

Sound Suggestions said:


> LOL, yes editorials are paid for, but not always reviewed favorably


I've yet to see a negative review of anything in a magazine article... the magazine is funded by advertisers, and thus they would go out of business posting any negativity. 

It's kind of like consumer reports, always finding some budget something that outperforms all... meanwhile the reality is, how many people would buy consumer reports if every article said "The most expensive in this test was the best performer".


----------



## WRX/Z28 (Feb 21, 2008)

RNBRAD said:


> Start on 2nd page under "statuesque". Interesting take.
> Pioneer Elite SC-68 A/V Receiver Page 2 | Home Theater


Is that guy talking about music? or disecting a body?


----------



## chad (Jun 30, 2005)

WRX/Z28 said:


> Via the transformer/power supply...


Actually the plates will glow cherry red til they deform and crash into the grid.

It's VERY VERY uncommon to lose a tube amp due to the transformers overheating unless they are being heavily abused.


----------



## WRX/Z28 (Feb 21, 2008)

chad said:


> Actually the plates will glow cherry red til they deform and crash into the grid.
> 
> It's VERY VERY uncommon to lose a tube amp due to the transformers overheating unless they are being heavily abused.


Are most tube amps class a?


----------



## RNBRAD (Oct 30, 2012)

WRX/Z28 said:


> Is that guy talking about music? or disecting a body?


The NAD review and skeletons reminded me of the Pioneer review. Must be same guy, loves skeletons I guess.


----------



## Sound Suggestions (Dec 5, 2010)

What facts are you looking for? My ears tells me that I hear a difference (subjective I guess) you don't hear a difference (your ears, subjective)

I'm actually quite easily pleased with music (because I love music) I just prefer it when everything clicks, a good amp will generate a nice wide accurate soundstage (a warm airy sound, 3 dimensional sound, full effortless sound) when done right goosebumps will appear


----------



## chad (Jun 30, 2005)

WRX/Z28 said:


> Are most tube amps class a?



No, but a class A tube amp is a different beast than a class A solid state. They run warm but by design THEY CANNOT be designed past plate dissipation AND it makes no sense to do so.

Class A tube amps of more than a few watts are not the most common things and can end up being huge.

Class AB amps are more notorious for thermal failure after the bias circuit fails somehow.


----------



## WRX/Z28 (Feb 21, 2008)

RNBRAD said:


> The NAD review and skeletons reminded me of the Pioneer review. Must be same guy, loves skeletons I guess.


I'm wondering how many other disection based adjectives he can use to describe sound. I don't know about the rest of you, but I feel that using whatever random adjectives are bouncing around his head to explain sound differences throw's credibility right out the window...


----------



## WRX/Z28 (Feb 21, 2008)

chad said:


> No, but a class A tube amp is a different beast than a class A solid state. They run warm but by design THEY CANNOT be designed past plate dissipation AND it makes no sense to do so.
> 
> Class A tube amps of more than a few watts are not the most common things and can end up being huge.


and are feasibly produced as a car amp?


----------



## co_leonard (Aug 14, 2009)

I'd just like to share:

I've heard some really good sounding systems in cars of other people, folks who join (and win) hardcore SQ competitions. Some use class D amps and some use Class-AB amps. Honestly speaking, it would be hard to say how much the "class of the amp" contributed to the overall sound of the system. I think speaker choice and tuning affect the sound the most. 

Only way to really find out how much the sound of the amp affects the sound of the entire system would be to swap them out with different amps. Sadly, this is something they aren't inclined to do. The trunks of their SQ competition cars have very good-looking woodworks/fiberglass/acrylic amp racks with nicely-dressed wires. Would be a lot of work to swap amps. And they believe that once the original amp has been returned (gains untouched, of course), something in the "sound" may change. 

One thing they do agree upon, though, is that amps DO SOUND DIFFERENT. 

Yes, the purpose of an amp is to increase signal gain. But in the real world, we have THD+N, power bandwidth, frequency response, damping and many other MEASURABLE factors that affect the sound.

Looking inside amplifiers can be an education in itself. The Ampguts site has many nice pictures. There are probably several hundred 50Wpc amplifiers there which will likely have audible differences. The most obvious audible difference will probably be heard comparing a cheap 50Wpc amp versus an expensive 50Wpc amp. 

The expensive amp would (among other things) be based on a better schematic, have a beefier power supply, use tighter-tolerance components such as matched transistors, have its bias and DC offset more ideally adjusted, use thicker copper in its circuit board, etc, etc... All these will definitely contribute to better measured performance compared to the cheap amplifier even if output wattage remains at 50W. 

And there are other "not-so-measurable" factors such as how an amp will interact (match) with a particular crossover network. I have personally auditioned cases where cheap amps sound thin, grainy and stressed when hooked up to a big passive crossover, like the Utopia Be No.7 passive (which I owned for a year and a half). Replacing it with a "better" amp improved the sound like night-and-day.

To be specific, the cheap amp was the Sound Magus CK75 and the "better" amp was the Zapco DC364 (with DSP off). Info on both amps are easily found online. The CK75 is rated 25W higher than the DC364 but it actually sounds 25W LESS POWERFUL in actual listening with the IASCA SQ CD.

If anyone can get a hold of those amps, I am certain the same conclusion would be arrived at.


----------



## chad (Jun 30, 2005)

WRX/Z28 said:


> and are feasibly produced as a car amp?


Absolutely, you just need the same high voltage supply that they use for car AB tube amps.

It's just a biasing scheme mang.


----------



## WRX/Z28 (Feb 21, 2008)

Sound Suggestions said:


> What facts are you looking for? My ears tells me that I hear a difference (subjective I guess) you don't hear a difference (your ears, subjective)
> 
> I'm actually quite easily pleased with music (because I love music) I just prefer it when everything clicks, a good amp will generate a nice wide accurate soundstage (a warm airy sound, 3 dimensional sound, full effortless sound) when done right goosebumps will appear


You probably should go back and start at the begining of the thread, since you clearly haven't read through. 


When done right, an amp will take the small signal coming from your source and make it MUCH BIGGER, yet still identical in composition. From there goosebumps will appear when your favorite track is played loud enough to simulate a live performance. 

3 dimensionalality illusions will present themselves when stereo reproduction is utilized correctly, regardless of which amplifier is used.


----------



## WRX/Z28 (Feb 21, 2008)

chad said:


> Absolutely, you just need the same high voltage supply that they use for car AB tube amps.
> 
> It's just a biasing scheme mang.



Hmmm... everything i've ever read suggested that true Class A was a near impossiblitity in the car due to size, current demand and heat production, and that even if such a device existed, it wouldn't make enough power to sound better than your average deck amp. Also, IIRC Most amps that have claimed to be Class A have been sufficiently proven to be mistaken... or to be Class A/B in actuality.


----------



## WRX/Z28 (Feb 21, 2008)

co_leonard said:


> I'd just like to share:
> 
> I've heard some really good sounding systems in cars of other people, folks who join (and win) hardcore SQ competitions. Some use class D amps and some use Class-AB amps. Honestly speaking, it would be hard to say how much the "class of the amp" contributed to the overall sound of the system. I think speaker choice and tuning affect the sound the most.
> 
> ...


More conjecture and 0 facts. Can we get a button that says "No thanks for this useless and supremely factless post"


----------



## chad (Jun 30, 2005)

WRX/Z28 said:


> Hmmm... everything i've ever read suggested that true Class A was a near impossiblitity in the car due to size, current demand and heat production, and that even if such a device existed, it wouldn't make enough power to sound better than your average deck amp. Also, IIRC Many amps that have claimed to be Class A have been sufficiently proven to be mistaken... or to be Class A/B in actuality.


Yeah, some use the "class A" buzzword when they may have a class A circuit somewhere inside. or are biased lass A for a longer than normal period of time. But it's totally possible, I would not do it but think running something like horns.....

7 watts out of 2 EL84's.... which are prety damn small, think same socket as the "bottle head headunits" just half again as tall.


----------



## Sound Suggestions (Dec 5, 2010)

Sir your wrong, you assume that every amplifier will take that source signal and amplify the same way?...read co_leonard reply...this one I agree with 100%

Again I'm not here to say that class D sound bad, not the case...some class D will sound better than some class A/B amps that were mass produced with cheap components, I'm here to support that a well designed well manufactured class A/B will amplify(hopefully a good source signal) and give it that emotion that the original sound engineer had intended for us to hear


----------



## WRX/Z28 (Feb 21, 2008)

chad said:


> Yeah, some use the "class A" buzzword when they may have a class A circuit somewhere inside. or are biased lass A for a longer than normal period of time. But it's totally possible, I would not do it but think running something like horns.....


You learn something new every day I guess. Anyone in the world of car audio actually produce a true Class-A that you are aware of? or is it still a hypothetical beast?


----------



## chad (Jun 30, 2005)

I'm old enough now that I really don't give much of a **** about things that really don't interest me....

Class A car amplifiers really miss that interest list by a longshot.. IF I wanted one, I'd build one. I find enjoyment in building tube amps.


----------



## WRX/Z28 (Feb 21, 2008)

Sound Suggestions said:


> Sir your wrong, you assume that every amplifier will take that source signal and amplify the same way?...read co_leonard reply...this one I agree with 100%
> 
> Again I'm not here to say that class D sound bad, not the case...some class D will sound better than some class A/B amps that were mass produced with cheap components, I'm here to support that a well designed well manufactured class A/B will amplify(hopefully a good source signal) and give it that emotion that the original sound engineer had intended for us to hear


I'm glad you agree with a bowl full of opinion instead of the multitude of facts presented in this thread... 

Please quantify what makes an amp sound a certain way with specific examples cited that can be accurately reproduced and measured.

Also, please show me a schematic for the circuit that add's emotion in an amplifier...


----------



## Sound Suggestions (Dec 5, 2010)

WRX/Z28 said:


> You learn something new every day I guess. Anyone in the world of car audio actually produce a true Class-A that you are aware of? or is it still a hypothetical beast?


Wait for it............why bother with a class A when a class D will sound just as good! :laugh: just kidding, don't take offence


----------



## IDGAF (Dec 27, 2009)

Sound Suggestions said:


> Sir your wrong, you assume that every amplifier will take that source signal and amplify the same way?...read co_leonard reply...this one I agree with 100%
> 
> Again I'm not here to say that class D sound bad, not the case...some class D will sound better than some class A/B amps that were mass produced with cheap components, I'm here to support that a well designed well manufactured class A/B will amplify(hopefully a good source signal) and give it that emotion that the original sound engineer had intended for us to hear


You're cracking me up with the amp altering the sound to the exact specification that the sound engineer intended for us to hear. So, what he did was leave it clean in the booth, but hope you have an amp that will add some pleasing distortion? Is that your contention?


----------



## IDGAF (Dec 27, 2009)

Also, my favorite part of that NAD HT receiever review was the sarcasm that, "If it can't be measured then it must not exist. amirite? amirite?"

Lol. Apprently sound and what not is far too complicated to measure with crude, human, 21st century technology.


----------



## WRX/Z28 (Feb 21, 2008)

WRX/Z28 said:


> Here is my point, that probably got lost in the mindless "you're wrong, no you're wrong" nonsense of the last 3 pages.
> 
> 
> *Amps sound the same when power is the same.* Even in the event that i'm wrong about this, the difference is so minute, that I (as well as many many others) haven't been able to detect it through the huge pile of different equipment that I own when leveling the playing field.
> ...


Reiterated for late arrivals to the party...


----------



## WRX/Z28 (Feb 21, 2008)

IDGAF said:


> Also, my favorite part of that NAD HT receiever review was the sarcasm that, "If it can't be measured then it must not exist. amirite? amirite?"
> 
> Lol. Apprently sound and what not is far too complicated to measure with crude, human, 21st century technology.


I mean these days we can even measure ghost activity... yet the elusive reproduced sound is beyond us...


----------



## WRX/Z28 (Feb 21, 2008)

Sound Suggestions said:


> Wait for it............why bother with a class A when a class D will sound just as good! :laugh: just kidding, don't take offence


My point exactly, but if you'd been reading along the whole time, you would have known that.


----------



## Sound Suggestions (Dec 5, 2010)

IDGAF said:


> Also, my favorite part of that NAD HT receiever review was the sarcasm that, "If it can't be measured then it must not exist. amirite? amirite?"
> 
> Lol. Apprently sound and what not is far too complicated to measure with crude, human, 21st century technology.


Just a quick question, not to stray to far from the original OP, have you ever heard a NAD receiver? I have and actually owned one for a bit (773) 6/7 years ago...they are quite special, I ended up going with an Arcam avr250 (great sounding as well) but I miss the NAD to this day.

Do yourself a favor and visit a higher end home audio shop, bring your reference material and demo a few receivers with the same source and same speakers and then let me know if they all sound the same


----------



## chad (Jun 30, 2005)

I never really viewed NAD as being "high end" but rather than mid-level no ******** devices. Always wanted one, recently passed one up, need mo-powa.


----------



## ChrisB (Jul 3, 2008)

ChrisB said:


> With that said, I turned over a new leaf. If one believes their 20+ year old relics are better than something like the JL Audio HD series, then so be it. They have their reasons for running what they run, and I have mine. At least choice of gear is one of the few freedoms that we still have left. As long as they don't go overboard trying to convince me that their relics are better, I'll just sit here and laugh at the screen when they post as to how much better their 20+ year old amplifiers are than the modern day, JL Audio HD series.:laugh:


Quoting myself because I am laughing.

To all those who claiming to hear the difference, please tell me what precision measurement caused the difference that you are hearing between the different amplifiers. No, really, in all seriousness, I am awaiting your answer. I think it is fine time we put this topology war to rest, once and for all with some cold hard facts.

I'll be awaiting your answer.


----------



## WRX/Z28 (Feb 21, 2008)

Sound Suggestions said:


> Just a quick question, not to stray to far from the original OP, have you ever heard a NAD receiver? I have and actually owned one for a bit (773) 6/7 years ago...they are quite special, I ended up going with an Arcam avr250 (great sounding as well) but I miss the NAD to this day.
> 
> Do yourself a favor and visit a higher end home audio shop, bring your reference material and demo a few receivers with the same source and same speakers and then let me know if they all sound the same



I've done exactly that, and when all else was equal, they sound the same.


----------



## RNBRAD (Oct 30, 2012)

If a person "thinks" it's a different amplifier, it's going to sound different even if the amp was never changed. We can never scientifically pinpoint the variability of thought, which is really a 6th sense that controls the variability of the other 5 senses. Good luck ever coming to an agreement on anything.


----------



## WRX/Z28 (Feb 21, 2008)

When the supporters of "Amps sound different" really sit back and think about it, they'll come to the same conclusion the rest of us have. Trust me, every "Amps sound the same" guy was once a "amps sound different" guy. 

I'm still amazed that post 206 was completely ignored...


----------



## Sound Suggestions (Dec 5, 2010)

Maybe we've beat that poor horse to a bloody pulp


----------



## ChrisB (Jul 3, 2008)

WRX/Z28 said:


> When the supporters of "Amps sound different" really sit back and think about it, they'll come to the same conclusion the rest of us have. Trust me, every "Amps sound the same" guy was once a "amps sound different" guy.


I used to think that all amplifiers sounded different. Granted some did, and there was a reason for it.

I thought this amplifier had so much resolution, detail, and all that other audiophile mumbo jumbo. This is how it measured:









Oddly enough, after spending some time with the above amplifier it didn't sound quite right and gave me some weird distortion when listening to "Brain Damage" by Pink Floyd. Till this very day, everyone who has since owned that amplifier thinks I am crazy because it sounded perfectly fine to them.

In the end, I found that I actually preferred using something that measured like this:


----------



## RNBRAD (Oct 30, 2012)

It's not that amps sound different, it's that we hear the same amp differently. We taste the same piece of pie differently, we smell the same cologne differently.


----------



## MarkZ (Dec 5, 2005)

Sound Suggestions said:


> Pay particular attention to the top portion of page 2 (description of class D sound) and also the bottom half of page 2 (for non-believers)
> 
> NAD T 787 A/V Receiver | Home Theater
> 
> ...


----------



## IDGAF (Dec 27, 2009)

Sound Suggestions said:


> Just a quick question, not to stray to far from the original OP, have you ever heard a NAD receiver? I have and actually owned one for a bit (773) 6/7 years ago...they are quite special, I ended up going with an Arcam avr250 (great sounding as well) but I miss the NAD to this day.
> 
> Do yourself a favor and visit a higher end home audio shop, bring your reference material and demo a few receivers with the same source and same speakers and then let me know if they all sound the same


What makes you think I don't own a NAD or spend hours upon hours auditioning the finest equipment in the world?

This reminds me of the retarded loop I got into one night. I was looking at making my own RCAs and I got to reading about what solder to use. I must have read 100 articles/opinions on the different sonic signatures of similar material solders.

Really?


----------



## Darth SQ (Sep 17, 2010)

OMG!
Six f'n pages in one day?
WTF?
Doesn't anyone watch the Rose Parade or the bowl games anymore? 


Bret
PPI-ART COLLECTOR


----------



## MarkZ (Dec 5, 2005)

I'm still trying to figure out what "high quality parts" and "high tolerance" means. In just about every analog circuit I've designed, you practically pull a number out of a hat 99% of the time. If your circuit _isn't_ designed to use parts that operate within a range, rather than requiring specific values, then you did it wrong. Especially when you consider the temperature variations that you see in a power amplifier that's mounted in a vehicle. Vbe, beta... that **** floats all over the place during normal operation. If you're relying on precise values, then you have no idea what you're doing.


----------



## IDGAF (Dec 27, 2009)

PPI-ART COLLECTOR said:


> OMG!
> Six f'n pages in one day?
> WTF?
> Doesn't anyone watch the Rose Parade or the bowl games anymore?
> ...




Stuck at work. Arguing over nonsense is all I have!!!


----------



## Sound Suggestions (Dec 5, 2010)

PPI-ART COLLECTOR said:


> OMG!
> Six f'n pages in one day?
> WTF?
> Doesn't anyone watch the Rose Parade or the bowl games anymore?
> ...


:laugh: I told myself earlier that I would stop replying once it would hit 10 pages....almost there

Bed time for me (1:30am) goodnight folks!


----------



## co_leonard (Aug 14, 2009)

MarkZ said:


> I'm still trying to figure out what "high quality parts" and "high tolerance" means. In just about every analog circuit I've designed, you practically pull a number out of a hat 99% of the time. If your circuit _isn't_ designed to use parts that operate within a range, rather than requiring specific values, then you did it wrong. Especially when you consider the temperature variations that you see in a power amplifier that's mounted in a vehicle. Vbe, beta... that **** floats all over the place during normal operation. If you're relying on precise values, then you have no idea what you're doing.


Yes I agree with that.

The idea (I think) is to use the best possible parts in the final circuit, to achieve the lowest noise floor, widest bandwith and least THD+N (among other measurements).

Here's what I was told:

Regular run-of-the-mill carbon film resistors are rated at 5% tolerance. So a 1k-ohm resistor could either be 950 ohms or 1050 ohms. Usually brown-colored bodies, like this:










There are also 1% tolerance resistors, usually in blue bodies. Aside from tighter tolerance, it offers lower operating noise - which is IMHO helpful in car audio. 










I know for a fact a lot of high-quality (expensive) home and car audio gear use metal film resistors.

Here's another example:

This is a regular electrolytic capacitor:









That one costs roughly US$0.10 each. Sometimes even less.

And here is an example of a high-quality, tight-tolerance electrolytic capacitor:










That one costs around US$5.00 each and is quite rare.

Benefits? Low ESR, Temperature stability, and leads made from oxygen-free-copper.

Here's an article on that capacitor straight from the manufacturer: Aluminum electrolytic capacitors for audio applications - Features of the SILMIC series | ELNA

I know Clarion uses this exact capacitor in its acclaimed DRZ-9255 head unit. I saw a lot of them when I opened up mine. 

To replace them with the cheaper parts would, no doubt, result in a degraded measurement. Greater THD+N, higher noise floor, poor bandwidth, etc... 

Please note I am not an expert and all this information I got from own experience and other sources more knowledgable than me.


----------



## Richv72 (May 11, 2012)

PPI-ART COLLECTOR said:


> OMG!
> Six f'n pages in one day?
> WTF?
> Doesn't anyone watch the Rose Parade or the bowl games anymore?
> ...


Its a good topic for debate.


----------



## sqnut (Dec 24, 2009)

PPI-ART COLLECTOR said:


> OMG!
> Six f'n pages in one day?
> WTF?
> Doesn't anyone watch the Rose Parade or the bowl games anymore?
> ...


True, but fun to read and watch


----------



## MarkZ (Dec 5, 2005)

co_leonard said:


> Yes I agree with that.
> 
> The idea (I think) is to use the best possible parts in the final circuit, to achieve the lowest noise floor, widest bandwith and least THD+N (among other measurements).
> 
> ...



But my point was that none of those things actually matter in a _*circuit*_.

We don't care about Johnson noise in circuits with impedances on the order of kohms or less. So the noise performance of resistors doesn't matter.

ESR/ESL for larger capacitors can be an issue, but that's why god invented bypass caps. 

Measuring the performance of parts _by themselves_ doesn't actually make any sense, when circuits use local feedback or mirrors or current sources or tracking circuits, etc. There are very few parts in an amp whose values need to be precise. I'd actually be wary of an amp that required too many high tolerance parts.


----------



## thehatedguy (May 4, 2007)

Someone just posted a link to the one I have.

Parallel single ended tubes in class a. Mine is 30x2, they have a 40x2 too.



WRX/Z28 said:


> and are feasibly produced as a car amp?


----------



## Hanatsu (Nov 9, 2010)

Bought an used DLS TA2 a year ago (had it for 3 weeks before I sold it again). That's an A/B tube amp. The damn warmup time during the winter drove me insane. Took roughly 1min before the amp was heated up and like two additional minutes before it sounded "right". Great amps otherwise but there's no audible improvement over my current Ultimate amps imo, even though they are considered to be more high-end with tubes and 'silver caps' and crap... Run my mids off an Alpine PDX amp now instead (first gen xD). No issues whatsoever with it though, nice small amp with lots of power.


----------



## benny (Apr 7, 2008)

thehatedguy said:


> Someone just posted a link to the one I have.
> 
> Parallel single ended tubes in class a. Mine is 30x2, they have a 40x2 too.


23 amps idle current!


----------



## MarkZ (Dec 5, 2005)

benny said:


> 23 amps idle current!


Thing should run directly off the fuel line.


----------



## LovesMusic (Mar 29, 2012)

Lol ^

Wrx/z28- you have a bridge to sell, don't you...


Mark why don't the tighter tolerance resistors and caps make for faster more precise transients @ a function of time....


----------



## thehatedguy (May 4, 2007)

Well, it's very large and heavy too...but good news is it shouldn't draw any more current when rocking full tilt since it is class a. Sounds incredible on the horns.

But I am still waiting on a blameless based car amp...maybe I should build one myself using another amp for it's heatsink and power supply.

But then again, I am really really happy with my JL HD class d amps to really even mess with building something.


----------



## ChrisB (Jul 3, 2008)

benny said:


> 23 amps idle current!


You can put that under your seat. That way, it will double as a space heater too.:laugh:


----------



## SaturnSL1 (Jun 27, 2011)

I really want to go ahead and measure the idle current of my USA400 now. It's THE best amplifier I've ever heard when it comes to clarity and warmth (yes, I know, vague words to describe what is most likely my own imagination). I've never heard an amplifier sound so good, even on some old ass half blown green Kappa coaxials. I wonder if it takes more power than it makes...

I want to install it today, for sub duty on two Sundowns but the damned thing sounds so good to me that I might throw it in for my front stage... Can you say over kill?


----------



## benny (Apr 7, 2008)

SaturnSL1 said:


> I really want to go ahead and measure the idle current of my USA400 now. It's THE best amplifier I've ever heard when it comes to clarity and warmth (yes, I know, vague words to describe what is most likely my own imagination). I've never heard an amplifier sound so good, even on some old ass half blown green Kappa coaxials.* I wonder if it takes more power than it makes...
> *
> I want to install it today, for sub duty on two Sundowns but the damned thing sounds so good to me that I might throw it in for my front stage... Can you say over kill?


They ALL take more power than they make


----------



## MarkZ (Dec 5, 2005)

LovesMusic said:


> Mark why don't the tighter tolerance resistors and caps make for faster more precise transients @ a function of time....


Why would they?

Think about what "precise" means. "Precise" means fitting your circuit design. If you design a circuit to do something, and you designed it to use a 1k resistor, then you need to analyze what happens to that circuit when you use a 1.1k resistor instead. Or a 2k resistor. The behavior of a circuit when you swap out a resistor is going to depend on what that circuit _is_ and what its place is in the whole circuit. Smart designs try to minimize the impact of precision, partially because they know that the values of these components change when the temperature changes. If your design requires precision, it's usually a bad design.


----------



## SaturnSL1 (Jun 27, 2011)

Mark, is there any good literature you could recommend to a person who wants to design their own amplifier?

This should probably be a PM, sorry.


----------



## thehatedguy (May 4, 2007)

ONly seat it is fitting under is a semi truck. I think it's about 9" tall.

My Monolithic 501A class amps would get so hot you could smell them. I need to put them back together someday...was using the power supply and heat sinks with a DIY Pass Mini Aleph board in them, about 25 watts pure class A at the current rail voltages.




ChrisB said:


> You can put that under your seat. That way, it will double as a space heater too.:laugh:


----------



## thehatedguy (May 4, 2007)

Douglas Self has a nice book or two if you are talking solid state.

There are a couple of his designs being built and modified on DIY Audio in the solid state section. 

Dx Blame ST together Dx Super A - diyAudio

Caught my eye. A "blameless" and runs class A for a few watts.



SaturnSL1 said:


> Mark, is there any good literature you could recommend to a person who wants to design their own amplifier?
> 
> This should probably be a PM, sorry.


----------



## SaturnSL1 (Jun 27, 2011)

thehatedguy said:


> Douglas Self has a nice book or two if you are talking solid state.
> 
> There are a couple of his designs being built and modified on DIY Audio in the solid state section.
> 
> ...


Thanks! I'm looking to build my own car amp, class A/B. I want to start small to get my feet wet but my goal is to build something that'll make big power


----------



## MarkZ (Dec 5, 2005)

SaturnSL1 said:


> Mark, is there any good literature you could recommend to a person who wants to design their own amplifier?
> 
> This should probably be a PM, sorry.


Probably a psychology book called "WTF is wrong with me?" followed by the Bible, because you're gonna need it.

I'd start with any transistor circuits book. There are more specialized books (I like the switchmode power supply handbook by I forget who, and I like Randy Slone's amplifier design book a lot), but those books won't make any sense until you feel good about transistor circuit design.

Then, when the fire department is at your house, go to one of the audio forums (diyaudio.com is good) where they can tell you why your design was a bad idea. Then, a few hundred dollars later, you can get it working.

That's when your kid breaks it, and you go on ebay and buy a $10 chip amp and call it a day.


----------



## Hanatsu (Nov 9, 2010)

MarkZ said:


> Probably a psychology book called "WTF is wrong with me?" followed by the Bible, because you're gonna need it.
> 
> I'd start with any transistor circuits book. There are more specialized books (I like the switchmode power supply handbook by I forget who, and I like Randy Slone's amplifier design book a lot), but those books won't make any sense until you feel good about transistor circuit design.
> 
> ...


:laugh::laugh::laugh::laugh:


----------



## SaturnSL1 (Jun 27, 2011)

Hahah thanks for the recommendation! I'm going to start with Randy's book, seems like a good start. 

Actually, I'm going to look in the psychology section first


----------



## Hanatsu (Nov 9, 2010)

TDA2030A 14W Hi-Fi Audio Amplifier IC Low Harmonic And Cross-Over Distortion | eBay

Looks easy enough to assemble ^.^


----------



## SaturnSL1 (Jun 27, 2011)

cajunner said:


> but I have to admit, I use what is possibly one of the most maligned amps ever, a Sony Xplod class D amp on my subs, and it sounds...
> 
> 
> great!
> ...


Gotta agree with you about reputation VS whats real. All I ever hear about Legacy/Pyramid is that it's complete junk that should be avoided but my old LA420 was a TANK that was overrated in terms of power but severely underrated in terms of reliability and quality.


----------



## SaturnSL1 (Jun 27, 2011)

What do you mean by "tinkering"? I've already bought a few simple Velleman amp kits but that's just simple assembly.

Velleman 7W Mono Audio Amplifier Kit 320-214


----------



## MarkZ (Dec 5, 2005)

thehatedguy said:


> Well, it's very large and heavy too...but good news is it shouldn't draw any more current when rocking full tilt since it is class a. Sounds incredible on the horns.
> 
> But I am still waiting on a blameless based car amp...maybe I should build one myself using another amp for it's heatsink and power supply.
> 
> But then again, I am really really happy with my JL HD class d amps to really even mess with building something.


But the concept of blameless is what we argue about in here all the time. How much distortion can you really hear? Under what conditions can you detect X%? Is the noise we experience in car audio dominated by the amp, by the install, or by the interaction of the two? Does a slight (but smooth) frequency response dip matter when you're going to EQ anyway?

And what does blameless even matter if your transients are clipped?


----------



## MarkZ (Dec 5, 2005)

Hanatsu said:


> TDA2030A 14W Hi-Fi Audio Amplifier IC Low Harmonic And Cross-Over Distortion | eBay
> 
> Looks easy enough to assemble ^.^


Yeah!

I have a LM3875-based one for my HT sound bar.

Kit for GAINCLONE 3875 LM3875 50W+50W 8ohm Amplifier board+speaker protection SC | eBay

How do you do it in a car though? They want +/-25v I think. Yours wants +/-14v.


----------



## Hanatsu (Nov 9, 2010)

MarkZ said:


> Yeah!
> 
> I have a LM3875-based one for my HT sound bar.
> 
> ...


How do they do it in car amps? Input DC 12V - AC conversion, transformed and then rectified again to DC target rail voltage?

Ain't there some DIY circuit for this or is it complicated to build for a beginner?


----------



## MarkZ (Dec 5, 2005)

Too complicated to do efficiently. There are generic SMPS boards, but they're expensive.


----------



## BassnTruck (May 27, 2010)

Hanatsu said:


> How do they do it in car amps? Input DC 12V - AC conversion, transformed and then rectified again to DC target rail voltage?
> 
> Ain't there some DIY circuit for this or is it complicated to build for a beginner?


No



MarkZ said:


> How do you do it in a car though? They want +/-25v I think. Yours wants +/-14v.


A step up transformer or a voltage regulator. You can turn that 12v to 25v easily. But as you know to increase voltage you will be pulling a lot of current to do it.


----------



## MarkZ (Dec 5, 2005)

BassnTruck said:


> No
> 
> 
> 
> A step up transformer or a voltage regulator. You can turn that 12v to 25v easily. But as you know to increase voltage you will be pulling a lot of current to do it.


Can't step up DC. Getting +/-25v is no easy task. Requires a switcher. That's either going to be inefficient as hell or expensive.


----------



## BassnTruck (May 27, 2010)

MarkZ said:


> Can't step up DC. Getting +/-25v is no easy task. Requires a switcher. That's either going to be inefficient as hell or expensive.


Getting 25v from 12v is easy. I never said it would be cheap to do in the current he may need. Inefficiency was a given.


----------



## t3sn4f2 (Jan 3, 2007)

BassnTruck said:


> Getting 25v from 12v is easy. I never said it would be cheap to do in the current he may need. Inefficiency was a given.


----------



## MarkZ (Dec 5, 2005)

BassnTruck said:


> Getting 25v from 12v is easy. I never said it would be cheap to do in the current he may need. Inefficiency was a given.


What would you buy to accomplish this?


----------



## thehatedguy (May 4, 2007)

Page Title


----------



## thehatedguy (May 4, 2007)

I want one for my horns to get rid of crossover distortion...which is why I like class A on horns- no crossover distortion.

But for every other speaker, like the common 87 dB and down sensitive, wouldn't matter much IMO...and matter less the lower you go in sensitivity.



MarkZ said:


> But the concept of blameless is what we argue about in here all the time. How much distortion can you really hear? Under what conditions can you detect X%? Is the noise we experience in car audio dominated by the amp, by the install, or by the interaction of the two? Does a slight (but smooth) frequency response dip matter when you're going to EQ anyway?
> 
> And what does blameless even matter if your transients are clipped?


----------



## BassnTruck (May 27, 2010)

MarkZ said:


> What would you buy to accomplish this?


Depends on how many amps of current at the 25v are being needed.


----------



## Richv72 (May 11, 2012)

Now i wonder, ive been to the zapco website, and they claim they tried many different caps and components. They claim that the components do in fact change the sound of the amplifier. So is zapco lying or do amps indeed sound different based on what parts they use?. So if zapco is not lying on their website and changing components do indeed make an amp sound different, then wouldnt changing topologies have the same effect?. Unless of course the amps were made by the same company using the same caps and such.

This is from zapcos website describing the new z series amp:

What we found was that electrolytic caps, mylar caps, and tantalum caps all sound different. Different Op-Amps sound different...even if they have the same engineering specs. Output devices all sound different even though they put out the same voltages. Even the layout of components on a board will affect the sound of an amplifier. And ultimately, we found that different combinations of Op-amps, capacitors, and output devices allowed us to make a major difference in the sound quality of the amplifiers without changing the specs.
The Zapco Z-Series amplifiers use the best combination of NJM5532L and OPA2134 op-amps, Tantalum capacitors, and high speed KEC and Sanken output devices to bring you what we believe are the best sounding amplifiers we have ever offered.


----------



## MarkZ (Dec 5, 2005)

BassnTruck said:


> Depends on how many amps of current at the 25v are being needed.


Enough to power a few (4?) channels of those chip amps. So... not much. I've found one for about $240 shipped. That's about the cheapest I've found.


----------



## MarkZ (Dec 5, 2005)

Richv72 said:


> Now i wonder, ive been to the zapco website, and they claim they tried many different caps and components. They claim that the components do in fact change the sound of the amplifier. So is zapco lying or do amps indeed sound different based on what parts they use?.


The zapco salesman is providing information that puts zapco products in a positive light.

Salesmen and marketing departments should NEVER EVER EVER be used as sources of information. The reason for this should be obvious.


----------



## Darth SQ (Sep 17, 2010)

Richv72 said:


> Now i wonder, ive been to the zapco website, and they claim they tried many different caps and components. They claim that the components do in fact change the sound of the amplifier. So is zapco lying or do amps indeed sound different based on what parts they use?. So if zapco is not lying on their website and changing components do indeed make an amp sound different, then wouldnt changing topologies have the same effect?. Unless of course the amps were made by the same company using the same caps and such.
> 
> This is from zapcos website describing the new z series amp:
> 
> ...


This is a good point and one that I have been hesitant to make because in no way shape or form am I an electronic engineer; aerospace yes, but electronic no.
However, my PPI tech pointed out that these blue horizontal mylar caps used in all my Art .2 amps were specifically chosenby PPI engineers because they they give the sound the warmth of a tube amp.



Bret
PPI-ART COLLECTOR


----------



## BassnTruck (May 27, 2010)

MarkZ said:


> Enough to power a few (4?) channels of those chip amps. So... not much. I've found one for about $240 shipped. That's about the cheapest I've found.


If you are talking about this one.
Kit for GAINCLONE 3875 LM3875 50W+50W 8ohm Amplifier board+speaker protection SC | eBay

His page says


> Recommended voltage AC 25-0-25 AC supply


Might want to check with him it is indeed AC. His engrish not so goo.


----------



## sqshoestring (Jun 19, 2007)

You are better off to buy a cheap class AB car amp and use that PS. Get an insignia/kole/power acoustik/spl they are pretty simple.

I can't keep up here, I have a NAD in the house and it works ok. Its an old receiver just 2ch. Also have an old pioneer 2ch amp. But both are pos compared to my HK amp lol. The NAD may have similar quality but is gutless, rated power must be very optimistic. I'll guess they are all class AB. The HT amps I have now are class D.

Amps? Check out diyaudio.com first. For car amps get the repair disk from Perry, bcae1.com you will learn tons. You can do his site for free.

You have to remember the actual audio signal is only affected by certain parts in an amp, most of the amp does not have audio running through it.


----------



## chad (Jun 30, 2005)

PPI-ART COLLECTOR said:


> However, my PPI tech pointed out that these blue horizontal mylar caps used in all my Art .2 amps were specifically chosenby PPI engineers because they they give the sound the warmth of a tube amp.
> 
> 
> 
> ...


Getting deep in here now. 'scuse me while I nab my hip waders, I don't like my balls touching tall ****.


----------



## co_leonard (Aug 14, 2009)

MarkZ said:


> But my point was that none of those things actually matter in a _*circuit*_.
> 
> We don't care about Johnson noise in circuits with impedances on the order of kohms or less. So the noise performance of resistors doesn't matter.
> 
> ...


Yup, I fully understand that. I have built several amps in my youth.

Studying different audio brochures and catalogs (both home and car) will reveal a fact: as you go up the product line of a manufacturer, the more expensive products usually use "branded" or specially designed internal components.

For example, the Clarion DRZ-9255 uses higher-end Burr-Brown chips and ELNA Silmic capacitors. The Pioneer DEX-P99RS uses higher-end AKM DSP chips. The Alpine PXA-H800 processor uses two 32-Bit floating-point SHARC DSPs. And as mentioned certain amps use higher-end opamps in their input stages.

None of these are actually "required." Alpine could have used a lower-spec DSP that would still get the job done. Clarion could have used cheap generic chips and capacitors that would still get the job done. Etc, etc, etc... 

I believe those higher-end close-tolerance parts were chosen for the final product because the manufacturer wanted:
(1) The final product to use the best possible parts
(2) To achieve the best possible performance (sound and measurements)
(3) To give the customer the best value for money

Three goals that I believe we all would agree with in the quest for better sound.


----------



## co_leonard (Aug 14, 2009)

Richv72 said:


> Now i wonder, ive been to the zapco website, and they claim they tried many different caps and components. They claim that the components do in fact change the sound of the amplifier. So is zapco lying or do amps indeed sound different based on what parts they use?. So if zapco is not lying on their website and changing components do indeed make an amp sound different, then wouldnt changing topologies have the same effect?. Unless of course the amps were made by the same company using the same caps and such.
> 
> This is from zapcos website describing the new z series amp:
> 
> ...


This is exactly my point. Higher-end components used in a well-engineered product all contribute to better performance. 

The Zapco engineers knew they did not need to use high-end components, but they specified them for the Z-series. That's why it sounds as good as it does.


----------



## MarkZ (Dec 5, 2005)

BassnTruck said:


> If you are talking about this one.
> Kit for GAINCLONE 3875 LM3875 50W+50W 8ohm Amplifier board+speaker protection SC | eBay
> 
> His page says
> ...


No, most of those are AC. They throw a rectifier on the board. But it doesn't matter... you still have to convert to AC to step up the voltage.


----------



## MarkZ (Dec 5, 2005)

cajunner said:


> this brings up a good point.
> 
> what about when you change a capacitor from electrolytic to film?
> 
> ...





cajunner said:


> I think the use of high grade capacitors in the pre-amp or driver sections of most amps is where you get the best case scenario of a sonic "flavor" represented by changes in components.
> 
> the old Kenwood Supreme 700C that EchoWars does the cap switcharoo on in the AudioKarma threads, has him changing out the electrolytics for films, and he says it takes it to another level.
> 
> Granted, with a 50V plus or minus of schwing, and a soft start on a preamp, the 700C is not your average bear..



Like I said earlier, it's less about the parts themselves and more about the circuits. You want to knock down distortion and noise, you don't do it by using different parts. You just don't.


----------



## co_leonard (Aug 14, 2009)

PPI-ART COLLECTOR said:


> This is a good point and one that I have been hesitant to make because in no way shape or form am I an electronic engineer; aerospace yes, but electronic no.
> However, my PPI tech pointed out that these blue horizontal mylar caps used in all my Art .2 amps were specifically chosenby PPI engineers because they they give the sound the warmth of a tube amp.
> 
> 
> ...


I am also not an electronics engineer although I have built several home-audio amplifiers and speakers in the past. But I do appreciate the time, effort and energy the PPI designers put into their products. 

Years ago I once owned both the PPI A600 and A600.2 amplifiers and there is an audible difference in the two. I agree with Bret, the .2 sounds warmer.

Weeks of listening back and forth between those two amps proved that the A600.2 really did make Mary Black's voice sound less shrill than it normally is on "Columbus." Jennifer Warnes's voice can easily be pictured as coming from a floating ball dead-center in the soundstage on "Lights of Louisiane," with the acoustic guitar having a "surround sound" effect. Stevie Nicks's voice warbles nicely on "Dreams." Cymbal crashes and distorted guitars that would normally sound excessively bright on Aerosmith's version of "Come Together" are a lot easier on the ear. 

So I used the A600 with my midbass and the A600.2 with my tweeters. 

Regret selling them up until today.


----------



## MarkZ (Dec 5, 2005)

co_leonard said:


> Yup, I fully understand that. I have built several amps in my youth.
> 
> Studying different audio brochures and catalogs (both home and car) will reveal a fact: as you go up the product line of a manufacturer, the more expensive products usually use "branded" or specially designed internal components.
> 
> For example, the Clarion DRZ-9255 uses higher-end Burr-Brown chips and ELNA Silmic capacitors. The Pioneer DEX-P99RS uses higher-end AKM DSP chips. The Alpine PXA-H800 processor uses two 32-Bit floating-point SHARC DSPs. And as mentioned certain amps use higher-end opamps in their input stages.


It's funny... op amps aren't really "parts". They're circuits.  They're so commonly used circuits that they put them on a single chip. So the whole thing about tolerance doesn't really apply to them. At least no more than quality control of any circuit (like your amplifiers).


----------



## co_leonard (Aug 14, 2009)

MarkZ said:


> It's funny... op amps aren't really "parts". They're circuits.  They're so commonly used circuits that they put them on a single chip. So the whole thing about tolerance doesn't really apply to them. At least no more than quality control of any circuit (like your amplifiers).


Actually they do affect the sound. 

Like in the Burr-Brown family, there's the OPA2134 then there's the very expensive (I think 3 times the price) OPA2111 which a lot people say sounds much better. Then from another manufacturer comes the LT1364 opamp which many agree sounds even better.

From another forum, here's a nice article: Little Dot MK1 opamp rolling

My friends and I have heard the Little Dot Mark1 with some of these opamps and we concur with the threadstarter's findings - and this is with different headphones.


----------



## chad (Jun 30, 2005)

MarkZ said:


> No, most of those are AC. They throw a rectifier on the board. But it doesn't matter... you still have to convert to AC to step up the voltage.


You could hit it with bipolar voltage as it stands, the rectifier will sort it out... with some loss.

Might sound "warmer" with the added component though


----------



## Richv72 (May 11, 2012)

MarkZ said:


> Like I said earlier, it's less about the parts themselves and more about the circuits. You want to knock down distortion and noise, you don't do it by using different parts. You just don't.


So if I understand you correctly, you are saying if you take an amp board and remove all the components, caps, mosfets, everything. After that you then replace all of the components with different ones that are different brands and some made of different materials you will hear absolutely no difference at all. Is that what you are saying?.


----------



## Hanatsu (Nov 9, 2010)

http://nwavguy.blogspot.se/2011/08/op-amps-myths-facts.html?m=1

Sent from my Samsung Galaxy 3 via Tapatalk.


----------



## chad (Jun 30, 2005)

It's not uncommon for newbie techs that are google and forum programmed to swap out op amps in older mixing consoles, only to damn near lose their job.


----------



## MarkZ (Dec 5, 2005)

Richv72 said:


> So if I understand you correctly, you are saying if you take an amp board and remove all the components, caps, mosfets, everything. After that you then replace all of the components with different ones that are different brands and some made of different materials you will hear absolutely no difference at all. Is that what you are saying?.



What I'm saying is if you built a good circuit designed around those "bad" parts, it will outperform the less-good circuit designed around boutique parts every damned time. When people talk about improving an amplifier's distortion performance, 99% of the time it involves improving the circuit, not just replacing the parts in it with more expensive ones.

Will it outperform it to the point where it will sound different? Well, that's kinda what the thread is about.


----------



## co_leonard (Aug 14, 2009)

Hanatsu said:


> NwAvGuy: Op Amps: Myths & Facts
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


Agreed. Very good article from someone with a solid engineering background. 

Opamp rolling or tube rolling or capacitor rolling or whatever rolling is (for those who do it), a genuine source of pleasure. It's what they like to do and they have the money to do it. Also, it causes no one any harm. I personally also do this from time to time. Yes the results are highly subjective but in the end, it is (at least for me), FUN. 

Just like car audio is fun. 

Although I will stand by what that guy did to get banned in the Head-Fi forum. Defective equipment, even if the manufacturer is a forum sponsor, must be reported and brought to light. 

I just can't help but wonder if some people in that forum took offense not at what he said, but how he said it.


----------



## LovesMusic (Mar 29, 2012)

MarkZ said:


> What I'm saying is if you built a good circuit designed around those "bad" parts, it will outperform the less-good circuit designed around boutique parts every damned time. When people talk about improving an amplifier's distortion performance, 99% of the time it involves improving the circuit, not just replacing the parts in it with more expensive ones.
> 
> Will it outperform it to the point where it will sound different? Well, that's kinda what the thread is about.


I understand now, and the harder I think about it the more sense it makes the way you described. 

So our "bad" parts are like a fraction in a math equation. Theyre there whether we like it or not but we can move the fraction around to "get rid of it" or make it sight unseen.. we take the "bad" or inexpensive parts in an amp circuit and simply move them around the circuit to in which case they become invisible to the circuit or now a non hinderence to the circuit?

And this is done to keep costs down? however designing these "better" circuit schematics is highly efficient in regards to a cost/performance aspect even though done with simple cheap components..


----------



## Hanatsu (Nov 9, 2010)

NwAvGuy: Subjective vs Objective Debate

Here's another interesting post by 'NwAwGuy' that fits the subject perfectly.


----------



## t3sn4f2 (Jan 3, 2007)

LovesMusic said:


> I understand now, and the harder I think about it the more sense it makes the way you described.
> 
> So our "bad" parts are like a fraction in a math equation. Theyre there whether we like it or not but we can move the fraction around to "get rid of it" or make it sight unseen.. we take the "bad" or inexpensive parts in an amp circuit and simply move them around the circuit to in which case they become invisible to the circuit or now a non hinderence to the circuit?
> 
> And this is done to keep costs down? however designing these "better" circuit schematics is highly efficient in regards to a cost/performance aspect even though done with simple cheap components..


I think it's more like ingredients in a recipe. Individually, there could be some that are "better" or "worse" but the combination of whichever ones can make a better product than the perceived sum of the high end individual parts.

And since nwavguy's blog has been popular in this thread, here's some more on what I mentioned above.

NwAvGuy: ODAC Update

"IT’S ABOUT WAY MORE THAN THE RIGHT PARTS: Using high-end parts is meaningless if the implementation is (often unknowingly) flawed. It’s like putting a Ferrari engine in a Yugo or using ultra fast RAM in a PC with a slow processor and chipset. It’s pointless. Just as cars are defined by far more than just their engine, and PC performance depends on several subsystems all working well together, the same is true of audio gear. The best products are from manufacturers that conduct proper testing and have the resources and desire to sweat all the little details rather than just using the latest FOTM parts and making it look nice.

FOLLOW THE PROFITS: Sadly a lot of “specialty” audio designers and companies seem to depend mainly on subjective hype and sighted listening bias, rather than proper design and objective performance, to sell their products. One can argue some are mainly trying to cash in on the latest FOTM craze rather than investing the time and money to design genuinely solid gear. It’s one of the goals of this blog to help not only expose half baked designs for what they are, but also demonstrate better alternatives don’t have to be be expensive or made with dual phase aligned unobtanium.

SMALL CHANGES CAN EQUAL BIG IMPROVEMENTS: I’ve sometimes been amazed how even small changes have made fairly large differences in the ODAC’s performance. Several of the ODAC’s optimizations run counter to typical DIY audiophile beliefs. Here are a few examples of typical design myths:

Larger Value Capacitors Are Better – “Upgrading” certain power supply capacitors to larger values made the ODAC perform significantly worse compared to using the values specified in the chip manufacturer’s reference design. Bigger value caps often have higher ESR, more inductance, and much higher impedance at very high frequencies. They can also create other problems.

Top & Bottom Ground Planes Should Be “Stitched” Together – Stitching is the practice of applying a board-wide grid of small vias (plated through holes) that connect the top and bottom ground planes. Some argue this lowers the ground impedance and keeps ground paths shorter. But they’re not true ground planes on a 2 layer board. Instead you have a bunch of ground fill areas isolated by signal and power traces. When you have these “ground islands” rather than a true continuous ground plane, the stitching can easily create undesirable ground loops and send ground currents where you don’t want them. I’ve seen several DIY and commercial designs ignore this issue and other proper grounding practices.

Expensive Audiophile Dielectric Capacitors Work Best – I experimented with various types of poly film caps, including audiophile preferred SMT Polyphenylene Sulphide (PPS) types, and found they sometimes made things worse. I also discovered not all ceramic caps perform equally. There’s no simple rule of thumb that always works. You have to make the right measurements and sweat the details. It’s time consuming but proved worth it. Every capacitor associated with the DAC chip and analog circuitry of the ODAC has been carefully optimized using the dScope. Overall, my capacitor tweaking resulted in lowering the noise and distortion by more than 6 db. And, trust me, the final result is not what your average DIYer would intuitively think is best.

Fully independent Analog & Digital Power Supplies Improve Performance – While there are probably a few high-end DACs that measure slightly better with fully independent digital and analog power supplies, the reality is the DAC chip itself and related digital noise is more likely the dominant limiting factor. I’ve shown, with multiple measurements and tests, the power supply is not holding the ODAC back in terms of performance. And while there’s some carefully designed filtering and ground routing between the analog and digital sections, they’re both derived from the same source. A DAC will only perform as well as its weakest link allows. In an optimized design that weak link is usually the DAC chip and/or a certain amount of unavoidable noise from the USB and I2S digital buses. When that’s true, adding more esoteric power supplies won’t help much if at all."


----------



## cubdenno (Nov 10, 2007)

Hanatsu said:


> NwAvGuy: Subjective vs Objective Debate
> 
> Here's another interesting post by 'NwAwGuy' that fits the subject perfectly.


What a great article!!


----------



## MarkZ (Dec 5, 2005)

And if you like that, check out this.  The Dan Rather Approved Douglas Self Site

* The most positive proof that Subjectivism is fallacious is given by subtraction testing. This is the devastatingly simple technique of subtracting before-and-after amplifier signals and demonstrating that nothing audibly detectable remains. It transpires that these alleged music-only mechanisms are not even revealed by music, or indeed anything else, and it is clear that the subtraction test has finally shown as non-existent these elusive degradation mechanisms. 

The subtraction technique was proposed by Baxandall in 1977. [17] The principle is shown in Fig 1.3; careful adjustment of the rolloff-balance network prevents minor bandwidth variations from swamping the true distortion residual. In the intervening years the Subjectivist camp has made no effective reply.

A simplified version of the test was introduced by Hafler. [18] This method is less sensitive, but has the advantage that there is less electronics in the signal path for anyone to argue about.
*


----------



## ChrisB (Jul 3, 2008)

Hanatsu said:


> NwAvGuy: Subjective vs Objective Debate
> 
> Here's another interesting post by 'NwAwGuy' that fits the subject perfectly.


You better watch it, pretty soon the nuthuggers on the forum will come out in droves to say you have some sort of agenda. I know because it happened to me the last time I exposed some BS.:laugh:

The only difference is now I understand why I heard what I heard and why extended listening revealed distortion that shouldn't have been there. Intentional sound coloration through equalization and harmonic distortion were the root causes of what I heard. 

My fault was not looking at the time period the amplifier was manufactured. MANY amplifier manufacturers were sending out products that had pre-equalization built into them just to make them stand out from the other ones on a dealer's soundboard. Listen to a couple of flat responding amplifiers the average person will be slightly impressed. Switch over to the one that has a built-in Fletcher-Munson curve with some added even order harmonic distortion, and watch their eyes pop out their head while claiming it is a miracle that it sounds so different. Ahh, I don't miss the 80s at all.

Now, for all the naysayers who still haven't answered my question... What measurement makes your class a, ab, gh, d, or any other yet to be identified power class topology sound different from the other? Going further, how can you realistically tell which is better while actually driving the vehicle?


----------



## Richv72 (May 11, 2012)

ChrisB said:


> You better watch it, *pretty soon the nuthuggers on the forum will come out* in droves to say you have some sort of agenda. I know because it happened to me the last time I exposed some BS.:laugh:
> 
> The only difference is now I understand why I heard what I heard and why extended listening revealed distortion that shouldn't have been there. Intentional sound coloration through equalization and harmonic distortion were the root causes of what I heard.
> 
> ...


No one judges how the car sounds while driving. Do they make you drive around at car sq shows?


----------



## thehatedguy (May 4, 2007)

I might get flammed for this, but there are 2 instances in which I think you could hear opamp changes and such...headphone amps that are using the opamp as the actual amp, and using high efficiency drivers in which you are listening to factions of a watt.

But that is just me. I like to do changes because most of the time I have a goal of having horns in the car in some fashion...and the horn channels get the major love.


----------



## ChrisB (Jul 3, 2008)

Richv72 said:


> No one judges how the car sounds while driving. Do they make you drive around at car sq shows?


I wouldn't know because the only car audio organization available within 1 hour's driving distance is a joke. I could show up, take first in my class, and not even so much as have a judge sit in my car. How's that for a car audio sq show?

But everyone keeps dodging the first question. They hear a difference between amplifiers and swear by it... So... What measurement is causing them to hear the said difference in the worst ever environment for audio reproduction known to human kind?


----------



## LovesMusic (Mar 29, 2012)

ChrisB said:


> I wouldn't know because the only car audio organization available within 1 hour's driving distance is a joke. I could show up, take first in my class, and not even so much as have a judge sit in my car. How's that for a car audio sq show?
> 
> But everyone keeps dodging the first question. They hear a difference between amplifiers and swear by it... So... What measurement is causing them to hear the said difference in the worst ever environment for audio reproduction known to human kind?




It is because no two brains interpret the sounds they hear identically...

mathematics aside audio is relative...so the "measurement" is relative


----------



## Darth SQ (Sep 17, 2010)

ChrisB said:


> You better watch it, pretty soon the nuthuggers on the forum will come out in droves to say you have some sort of agenda. I know because it happened to me the last time I exposed some BS.:laugh:
> 
> The only difference is now I understand why I heard what I heard and why extended listening revealed distortion that shouldn't have been there. Intentional sound coloration through equalization and harmonic distortion were the root causes of what I heard.
> 
> ...


That's the "PUNCH"!


Bret
PPI-ART COLLECTOR


----------



## RNBRAD (Oct 30, 2012)

ChrisB said:


> You better watch it, pretty soon the nuthuggers on the forum will come out in droves to say you have some sort of agenda. I know because it happened to me the last time I exposed some BS.:laugh:
> 
> The only difference is now I understand why I heard what I heard and why extended listening revealed distortion that shouldn't have been there. *Intentional sound coloration **through equalization and harmonic distortion were the root causes of what I heard.*
> 
> ...


Yes, people like their distortion in many flavors. And not just that it's perceived different, it is also perceived as a better sound!!! You hit the effin nail on the head with those comments!!! Funny thing is most people don't recognize that's what it is. Well if it sounds better to me, no way if it sounds better that it can be distortion or colour. It has to be cleaner if it sounds better!!!!:laugh:


----------



## ChrisB (Jul 3, 2008)

LovesMusic said:


> It is because no two brains interpret the sounds they hear identically...
> 
> mathematics aside audio is relative...so the "measurement" is relative


Same brain, different amps... I'm not buying your answer!:laugh:



PPI-ART COLLECTOR said:


> That's the "PUNCH"!
> 
> 
> Bret
> PPI-ART COLLECTOR


It wasn't just "The Punch" although other amplifiers started adding defeatable equalization after the Rockford Fosgate amplifiers caught on. IIRC, there others had a non-defeatable pre-patterned curve. MTX or Kicker comes to mind.


----------



## ChrisB (Jul 3, 2008)

RNBRAD said:


> Yes, people like their distortion in many flavors. And not just that it's perceived different, it is also perceived as a better sound!!! You hit the effin nail on the head with those comments!!! Funny thing is most people don't recognize that's what it is. Well if it sounds better to me, no way if it sounds better that it can be distortion or colour. It has to be cleaner if it sounds better!!!!:laugh:


Now tell one of these guys they like what they like due to intentional coloration and added harmonic distortion. Duck while their heads explode.


----------



## Hoye0017 (Mar 23, 2010)

This is from that subjective vs objective article, which I thoroughly enjoyed:

GRAY AREA (added 5/31): There’s a solid consensus on the subjective nature of speakers, headphones and phono cartridges but what about everything else? Most objectivists will tell you a $20 well designed interconnect and a $200 well designed interconnect will sound the same. And that’s been demonstrated many times (see Wired Wisdom above). Hardcore objectivists (such as Peter Aczel) argue any amp that measures sufficiently well and is operated well within its limits will be indistinguishable from any other amp. And that’s been demonstrated in countless blind listening tests. But what about when an amp nears its limits? What if you have difficult to drive speakers for example that are 2 ohms at some frequencies? Will the cheap amp still sound just like the high-end model? Perhaps not. Some of these behaviors can at least be partly measured but some are more difficult. And what defines “measures sufficiently well”? Enough studies have been done it’s fairly safe to make several generalizations, but there’s still room for discussion and further research in some areas. I’ll hopefully be publishing a future blog article on the topic of correlating specs with listening observations.

End quote.

This is definitely where I hear the difference in amps. At it's limit. I guess that's where I do the ear test. The limit can be reached in a few ways. One of which is handling low impedance points and handling peaks in current demand (basically the same thing). Does the amp have enough current capacity to handle the peak? What is it's true minimum load impedance? What happens to the output voltage when the current supply is stressed?

That's probably why I really like my "old school" high current amps that can handle loads below 1 ohm. I never feel like I'm reaching the limits of the amp before I reach the limits of the speaker. Basically their like big, hot, current valves. And I've been running them hard at low impedances for almost 10 years. 

I don't know enough about the designs of power supplies in class d amps to say that's what I'm hearing as a difference. But I believe only a handful are rated stable below 2 ohms. 

I would venture to guess that one of the audible differences between JL's HD amps and the XD amps (which i have in a different car) is the difference in power supply technology. HD amps are rated to 1.5 ohms, Xd's are not. I think I bought the XD thinking it would be "close enough." It is not.

Forget the class of amp, it's the size of the amp that is starting to become suspect to me. Again, I don't know enough about class D power supplies to say that's it but conventional wisdom in electronics has always dictated that a more robust power supply requires more space. 

For the record, I used to sell the pioneer elite receivers mentioned earlier, and the first word out of my mouth when I cranked it was "gutless." And at the time, I had no idea it was pioneer's take on class D.


----------



## RNBRAD (Oct 30, 2012)

ChrisB said:


> Now tell one of these guys they like what they like due to intentional coloration and added harmonic distortion. Duck while their heads explode.


I don't want to spoil it for them. Let them figure it out on their own. You know the old saying goes, what you don't know won't hurt you. It's probably better that way.  Heck the source material is manipulated with those attributes.


----------



## MarkZ (Dec 5, 2005)

cajunner said:


> manufacturers do it by using different parts.


No they don't. They communicate it that way because, as this thread proves, name brands are what the public understands. They don't understand circuits. A "Burr Brown op amp" is easier to sell than trying to explain to someone what the op amp circuit does, and how their engineers use it the best. In fact, "Burr Brown op amp" sells more amplifiers than a circuit that doesn't even need an op amp. Can't slap a brand name on a superior circuit.


----------



## MarkZ (Dec 5, 2005)

Hoye0017 said:


> Forget the class of amp, it's the size of the amp that is starting to become suspect to me. Again, I don't know enough about class D power supplies to say that's it but conventional wisdom in electronics has always dictated that a more robust power supply requires more space.


I agree with you on this point a lot. What's the most expensive part of an amp? The metal parts! The heatsink, the transformer, and the hardware. The good old weight test tells you a couple things about the design. First, it gives you a hint at how much the manufacturer invests to build each amp (yeah, it's a very rough approximation). And second, it tells you how efficient the amp is. The reason class D amps are smaller and lighter is because they generate less heat per output watt. So, although the weight test isn't a bad one, you can't really compare apples to oranges.


----------



## Hoye0017 (Mar 23, 2010)

MarkZ said:


> The reason class D amps are smaller and lighter is because they generate less heat per output watt. So, although the weight test isn't a bad one, you can't really compare apples to oranges.


I completely agree, I guess I wasn't trying to compare old beasty a/b's that have half a ton of heat sink to the class D's in size. I was thinking more in terms of comparing within the class. I've heard some of these new nano amps and really haven't been impressed with anything besides their size. Then look at the 2 most regarded class D's. their both almost identical in size, which is larger by comparison and both are pretty heavy.


----------



## LovesMusic (Mar 29, 2012)

How about the amps dampening? Dampening that will occur at each particular hz, will change given ohm load and final qtc, however the amount of dampening is determined by the amps circuit. That surely has direct correlation with reproduction of a sine wave..


----------



## Richv72 (May 11, 2012)

You keep your class d's, ill keep the a/b's.


----------



## co_leonard (Aug 14, 2009)

cajunner said:


> manufacturers do it by using different parts.
> 
> a DIY approach shouldn't be any different, depending on your definition of parts.
> 
> ...


I agree with you, Cajunner.

Plus there is a lot of fun in modifying or swapping internal components. Just like you can change your car engine's intake, headers and exhaust to aftermarket models to increase torque and horsepower. Or just like you can upgrade your computer's video card or get a bigger power supply or faster CPU and water cooling so that you can overclock it. There's a boatload of people who do this for recreation who understand that products are built from parts to fit a certain price point. And while upgrading certain parts can take their gear to the "next level," they learn something useful at the same time. 

I believe that's the point of our beloved hobby, car audio.


----------



## WRX/Z28 (Feb 21, 2008)

Hoye0017 said:


> This is definitely where I hear the difference in amps. At it's limit. I guess that's where I do the ear test. The limit can be reached in a few ways. One of which is handling low impedance points and handling peaks in current demand (basically the same thing). Does the amp have enough current capacity to handle the peak? What is it's true minimum load impedance? What happens to the output voltage when the current supply is stressed?



So you think that a difference when you're clipping an amp is worth something? Why not buy a cheaper amp that's twice as powerful so you don't clip it until ~3db higher? Problem solved, amps sound the same again, and you're being nicer to your speakers.



Hoye0017 said:


> That's probably why I really like my "old school" high current amps that can handle loads below 1 ohm. I never feel like I'm reaching the limits of the amp before I reach the limits of the speaker. Basically their like big, hot, current valves. And I've been running them hard at low impedances for almost 10 years.



Most of the "Amps sound different" guys also believe lower impedence sounds worse. If you mean you're running a 4 ohm load on a 1ohm stable amp, then your just making the amp sound worse by not utilizing all it's power capability...



Hoye0017 said:


> I don't know enough about the designs of power supplies in class d amps to say that's what I'm hearing as a difference. But I believe only a handful are rated stable below 2 ohms.



Why would you say that? There are dozens of 1ohm stable Class D amps dating back to the earliest models. 



Hoye0017 said:


> I would venture to guess that one of the audible differences between JL's HD amps and the XD amps (which i have in a different car) is the difference in power supply technology. HD amps are rated to 1.5 ohms, Xd's are not. I think I bought the XD thinking it would be "close enough." It is not.


The biggest difference is in the power capabilities, and the RIPS system is not in the XD amp. That's the reason for the impedence capability change, and it's only by .5ohm. FWIW, the reasoning behind the amps stability was to accomodate for their 3ohm subs. The difference in the power supply is that the XD's are not regulated or loosly regulated, the HD's are tightly regulated. The only benefit I see to HD vs. XD aside from the power capabilities is the crossover flexibility. You have more tuning options w/ HD. Oh, and the input capabilities. The HD has two different ranges on the the input/gain of the amp adjusted via a switch. 



Hoye0017 said:


> Forget the class of amp, it's the size of the amp that is starting to become suspect to me. Again, I don't know enough about class D power supplies to say that's it but conventional wisdom in electronics has always dictated that a more robust power supply requires more space.



At the same time, Class D amps are more efficient, and can utilize a smaller power supply, and a smaller heat sink to keep everything cool. 



Hoye0017 said:


> For the record, I used to sell the pioneer elite receivers mentioned earlier, and the first word out of my mouth when I cranked it was "gutless." And at the time, I had no idea it was pioneer's take on class D.


IMO that means it either made less power than other similarly rated receivers, or you happened to have it hooked up to less efficient speakers. 



co_leonard said:


> I agree with you, Cajunner.
> 
> Plus there is a lot of fun in modifying or swapping internal components. Just like you can change your car engine's intake, headers and exhaust to aftermarket models to increase torque and horsepower. Or just like you can upgrade your computer's video card or get a bigger power supply or faster CPU and water cooling so that you can overclock it. There's a boatload of people who do this for recreation who understand that products are built from parts to fit a certain price point. And while upgrading certain parts can take their gear to the "next level," they learn something useful at the same time.
> 
> I believe that's the point of our beloved hobby, car audio.


The difference is, the video card is a whole collection of circuits, the individual parts in the amp are not. You are actually adding entirely new engineered devices into your computer. Notice how they never have you soldering any new pieces on when you modify your computer? 

Swapping your amp parts is more like changing the color of the plastic used on your intake, or the metal your exhaust is made of. Sure longevity might be affected, but as long as the tubing is identical, the power results are identical.


----------



## ChrisB (Jul 3, 2008)

LovesMusic said:


> How about the amps dampening? Dampening that will occur at each particular hz, will change given ohm load and final qtc, however the amount of dampening is determined by the amps circuit. That surely has direct correlation with reproduction of a sine wave..



Heh, heh, you said damping factor. Marketers the world over are rejoicing because they managed to make you believe that a virtually useless spec is important with regards to audio reproduction.


----------



## SaturnSL1 (Jun 27, 2011)

Class D or Class A/B, you decide 










I'm loving this USA man. I've got it running my kicks right now and even with it running close to full tilt at 8 ohms for 20 minutes it stayed ice cold. Granted, it was probably 20 degrees outside...


----------



## NucFusion (Nov 28, 2010)

Hoye0017 said:


> I completely agree, I guess I wasn't trying to compare old beasty a/b's that have half a ton of heat sink to the class D's in size. I was thinking more in terms of comparing within the class. I've heard some of these new nano amps and really haven't been impressed with anything besides their size. Then look at the 2 most regarded class D's. their both almost identical in size, which is larger by comparison and both are pretty heavy.


Not all the nano amps out there are a true class d amp. If you are wanting to compare let's say, the jl xd vs the hd, sure there is a size difference, but the hd's are a tightly regulated power supply and has roughly twice the power as the biggest xd's. I don't believe that size has anything to do with sq. Any audible differences between these is most likely the power the hd has available over the xd.


----------



## MarkZ (Dec 5, 2005)

cajunner said:


> What circuit would that be, a discrete preamp circuit that arguably is better served by an op amp? I don't know where the use of an op amp in a circuit is a minus in car audio, I can understand in the relative expanse of pcb real estate in the home this being a moot point but op amps are a real adjunct into processing units that don't resemble professional mixing boards...




Haha wtf did you do to the font??

My point was that a piece of wire will outperform the best op amp any day of the week. Yet none of the manufacturers talk about their circuit being superior because it uses fewer op amps than another circuit. Instead they say, "Our amplifiers use the most delectable op amps and flavorful capacitors."

You only really need one op amp per channel, and that's just for the input buffer/gain circuit. And you don't even need that if you tie it together to a DAC (add this to your amplifier circuits thread..  ).




> Sure you can. Power Guard? haha..





> or Stasis, how about STASIS?


Touche...


----------



## LovesMusic (Mar 29, 2012)

ChrisB said:


> Heh, heh, you said damping factor. Marketers the world over are rejoicing because they managed to make you believe that a virtually useless spec is important with regards to audio reproduction.


There was a question mark in there smart ahhh...

You really get off on this huh...Explain yourself instead of coming off as an ahole..No reason to rub it in my face if you know something I dont....internet or not.. how old are you again?


BTW your the guy that came into my JL HD noise thread talking about how youve run many JL HD class D amps and they are surely not causing the noise distributed to my AM/FM radio, with some look at this chump attitude...
It was confirmed by JL that they do. and are.


----------



## MarkZ (Dec 5, 2005)

LovesMusic said:


> There was a question mark in there smart ahhh...
> 
> You really get off on this huh...Explain yourself instead of coming off as an ahole..
> 
> ...


----------



## LovesMusic (Mar 29, 2012)

> I would say it's like changing the paint on a sail boat.
> 
> some paints have performance differences, but to most people, it's just a color/gloss thing.



how about paint or stain on a guitar or lack there of? supposidly effects the sound characteristics of the instrument. But then again to most people it is probably a color thing... 

And from experience I have built a couple simple circuits in my labs and my calculated Xc or Xl, voltage, current, or final load etc has almost never been exact to measured results (especially as the circuit gets more complicated but always within a -+5% tolerance)... why cant this factor in... can coloration be introduced by a shotty soldering job?

Again for the bold and all knowing infiinite wisdom characters born here on DIYMA, this is nothing more then conjure... 

We have our bearings with class d voltage switching yet we cant capacitize a surge in a circuit...yikes


----------



## MarkZ (Dec 5, 2005)

cajunner said:


> I'm one of the optimists.
> 
> I think that if I can afford a Matt Roberts kludge job, it'll net me a marked improvement in noise floor, dynamic range, and freedom from compression, jitter, and clocking issues.
> 
> ...



DIYers pop out op amps and pop new ones in because it's do-able. A little more adventurous, you can recap your amp. The brave ones will pop out output transistors and put other ones in. 

But try replacing the VAS circuit in your amp. If you can do that, I'll give you an award.

Tinkerers tinker, builders build.


----------



## MarkZ (Dec 5, 2005)

cajunner said:


> well, that and it's not just a circuit, it's an operational amplifier. It governs whatever else is going to happen down circuit, it's the starting gate.
> 
> changing an op amp to one that has better specs just makes sense to most people who don't understand oscillation and current requirements, instability, etc.
> 
> ...


It's not really the starting gate. Like I said, you only _need_ an op amp to act like a buffer. So that would be like saying your RCA connector is your starting gate. The op amp, like the RCA connector, isn't actually part of your amplifier. It's in the amp because it kinda should be there so you can hook the thing up to other equipment (although you don't actually NEED either of them ).

[The exception are those companies that actually use op amps within the amplifier proper. For example, my a/d/s/ amp uses an op amp as the differential amplifier in the input stage. That's probably one that you _don't_ want to replace, for the reasons you mentioned.]


----------



## Richv72 (May 11, 2012)

MarkZ said:


> DIYers pop out op amps and pop new ones in because it's do-able. A little more adventurous, you can recap your amp. The brave ones will pop out output transistors and put other ones in.
> 
> But try replacing the VAS circuit in your amp. If you can do that, I'll give you an award.
> 
> Tinkerers tinker, builders build.


Lets see some pics of the amps you built. Lookout zapco, mark z is in the house.


----------



## SaturnSL1 (Jun 27, 2011)

My anus wasn't prepared for this.:disappointed:


----------



## MarkZ (Dec 5, 2005)

Richv72 said:


> Lets see some pics of the amps you built. Lookout zapco, mark z is in the house.


I don't build amps. For the same reason I don't build my own toaster, stitch my own clothes, or rake my own yard.

If you wanted to understand how they work, you'd talk less and read more. Your contribution in this thread has been zilch.


----------



## chad (Jun 30, 2005)

Dafuq is wrong with raking a yard?


----------



## MarkZ (Dec 5, 2005)

**** I'd rather watch paint dry.


----------



## chad (Jun 30, 2005)

MarkZ said:


> **** I'd rather watch paint dry.


It's an excuse to play with fire here.


----------



## MarkZ (Dec 5, 2005)

so is amp building for some folks


----------



## chad (Jun 30, 2005)

MarkZ said:


> so is amp building for some folks


Word to your mother.


----------



## RNBRAD (Oct 30, 2012)

Who in the heck rakes a yard anymore? That's what a leaf blower is for. Let your neighbors worry about it.


----------



## ChrisB (Jul 3, 2008)

RNBRAD said:


> Who in the heck rakes a yard anymore? That's what a leaf blower is for. Let your neighbors worry about it.


Going one step further, my new house has no trees on the lot. Naturally, we are about to embark on edible landscaping, so small fruit trees will probably be next on the agenda.


----------



## Darth SQ (Sep 17, 2010)

ChrisB said:


> Going one step further, my new house has no trees on the lot. Naturally, we are about to embark on *edible landscaping*, so small fruit trees will probably be next on the agenda.


Isn't that the name of a lesbian porn movie?


Bret
PPI-ART COLLECTOR


----------



## LovesMusic (Mar 29, 2012)

ChrisB said:


> Going one step further, my new house has no trees on the lot. Naturally, we are about to embark on edible landscaping, so small fruit trees will probably be next on the agenda.


I guess Ill refrain,

But dont you have a blog that would be more suitable for a comment with such importance...

Or I guess its settled class A/b sounds the same as class D


----------



## SaturnSL1 (Jun 27, 2011)

LovesMusic said:


> Or I guess its settled class A/b sounds the same as class D


Never and how dare you for making such a juvenile assumption.


----------



## ChrisB (Jul 3, 2008)

LovesMusic said:


> I guess Ill refrain,
> 
> But dont you have a blog that would be more suitable for a comment with such importance...


The point is, I have no leaves to rake therefore I don't have to pay someone to rake them nor rake them myself. Yet, that is.



LovesMusic said:


> Or I guess its settled class A/b sounds the same as class D


Come on old horse, we are going to keep beating you until you revive, just so we can beat you to death again! :dead_horse:


----------



## LovesMusic (Mar 29, 2012)

SaturnSL1 said:


> Never and how dare you for making such a juvenile assumption.



haa, just stirrin the pot up... or should we continue about leaves... 

btw get yourself some redmax blowers and the yards done 1 2 3..


----------



## Richv72 (May 11, 2012)

MarkZ said:


> I don't build amps. For the same reason I don't build my own toaster, stitch my own clothes, or rake my own yard.
> 
> If you wanted to understand how they work, you'd talk less and read more. Your contribution in this thread has been zilch.


Actually ive asked some good questions in this thread. Just because you "know it all" about circuits doesn't mean no one else can voice an opinion or ask questions.


----------



## LovesMusic (Mar 29, 2012)

ChrisB said:


> The point is, I have no leaves to rake therefore I don't have to pay someone to rake them nor rake them myself. Yet, that is.
> 
> 
> 
> Come on old horse, we are going to keep beating you until you revive, just so we can beat you to death again! :dead_horse:



So I will stress yet again, I dont have any indepth knowledge regarding amplifier operation but what I do know based on measuring tolerances in a circuit is that they fluctuate within the components spec'd tolerance. Each component has its own tolerance so this will translate to an overall deviation...

Looking at class d, it uses pulsewidth modulation of square waves which then is averaged or realistically speaking hypotenuced and filtered out to our sine wave. Surely knowing that there is circuit deviation, could this mean that each note in the dynamics of music will not be the same if measured..

say its the kick drum, well then we have a guitar, bass, singer, keyboardist and so on, ontop of that kick drum playing their own notes each note is hypotenuced for a sine wave right so each kick of the drum may deviate from one another based on the other square waves being manipulated...sorry Im bad at this...I know all of this is done in what ^-9 or ^-12 seconds..
then again if this were the case, in a class d circuit it would probably be the higher hz that would show the most deviation..
whether its off by a tenth or ten thousanths it will be off, coloration? lol...does this make any sense :blush:?

If not.. uhmm chrisB.. then please explain why.


----------



## MarkZ (Dec 5, 2005)

Richv72 said:


> Actually ive asked some good questions in this thread. Just because you "know it all" about circuits doesn't mean no one else can voice an opinion or ask questions.


Haha you? Ask questions?


----------



## MarkZ (Dec 5, 2005)

LovesMusic said:


> So I will stress yet again, I dont have any indepth knowledge regarding amplifier operation but what I do know based on measuring tolerances in a circuit is that they fluctuate within the components spec'd tolerance. Each component has its own tolerance so this will translate to an overall deviation...
> 
> Looking at class d, it uses pulsewidth modulation of square waves which then is averaged or realistically speaking hypotenuced and filtered out to our sine wave. Surely knowing that there is circuit deviation, could this mean that each note in the dynamics of music will not be the same if measured..
> 
> ...


Not sure what any of that means... hahaha

Tolerance of parts is not the same as accuracy of a circuit.

Like I said before. All parts -- even high tolerance ones -- change their properties with temperature. It's unavoidable. So if the circuits weren't designed to withstand this variation, there'd be an issue.

You guys should look at tolerance being more about QC than about performance.


----------



## ChrisB (Jul 3, 2008)

LovesMusic said:


> So I will stress yet again, I dont have any indepth knowledge regarding amplifier operation but what I do know based on measuring tolerances in a circuit is that they fluctuate within the components spec'd tolerance. Each component has its own tolerance so this will translate to an overall deviation...
> 
> Looking at class d, it uses pulsewidth modulation of square waves which then is averaged or realistically speaking hypotenuced and filtered out to our sine wave. Surely knowing that there is circuit deviation, could this mean that each note in the dynamics of music will not be the same if measured..
> 
> ...


My car audio needs are way more simplistic than most of the self-professed audiophiles on this forum. I know that road noise, reflections, refractions, and diffraction are par for the course with regard to car audio. With that said, I just want something that sounds better than stock and is noise free while overcoming the 50 to 60 Hz exhaust drone of my vehicle. 

Here is a simple flowchart as to how I pick amplifiers:


----------



## RNBRAD (Oct 30, 2012)

MarkZ said:


> Not sure what any of that means... hahaha
> 
> Tolerance of parts is not the same as accuracy of a circuit.
> 
> ...


Isnt the tolerance of a circuits parts related to its accuracy? Like if I build a circuit using resistors with a tolerance of 20% or I use a high precision resistors with a tolerance of 1%. That has nothing to do with the accuracy of the circuit? I think think the key here is use a circuit with the accuracy of what's required. But that circuits accuracy is based on the internal tolerances of its parts. 

Parts will change performance with temperature but how much will they change, that is the tolerance. Some will change by 1% some may change by 20%. The tighter or less variation in performance, isn't this not key to the precision and accuracy of a circuit, no?


----------



## Hoye0017 (Mar 23, 2010)

ChrisB said:


> My car audio needs are way more simplistic than most of the self-professed audiophiles on this forum. I know that road noise, reflections, refractions, and diffraction are par for the course with regard to car audio. With that said, I just want something that sounds better than stock and is noise free while overcoming the 50 to 60 Hz exhaust drone of my vehicle.
> 
> Here is a simple flowchart as to how I pick amplifiers:


So I'm confused. If that's your view on car audio amplifiers, why are you participating in a thread about differences in amplifier sound quality? If your requirements are noise free enough to not be noisier than your exhaust and better than stock, you could probably pick any amplifier on the market. Why spend the money on JL HD series?


----------



## MarkZ (Dec 5, 2005)

RNBRAD said:


> Isnt the tolerance of a circuits parts related to its accuracy? Like if I build a circuit using resistors with a tolerance of 20% or I use a high precision resistors with a tolerance of 1%. That has nothing to do with the accuracy of the circuit? I think think the key here is use a circuit with the accuracy of what's required. But that circuits accuracy is based on the internal tolerances of its parts.
> 
> Parts will change performance with temperature but how much will they change, that is the tolerance. Some will change by 1% some may change by 20%. The tighter or less variation in performance, isn't this not key to the precision and accuracy of a circuit, no?


Part values will change a TON with temperature. Nevermind 1%. Try 100%.  (That's not uncommon for transistor betas or Vbe's)

Again, I'm not saying you can replace any circuit element with any other. They're designed to operate with a range of values. Which is fortunate too, because the available values of standard circuit elements tend to be pretty coarse. For example, you can't buy a 452 ohm resistor. You'd have to get a 470. (or piece together a combination of resistors to give you 452 if you needed precision, but this doesn't happen that often in an amplifier)

There ARE cases where matching is beneficial, especially in certain push-pull circuits or thermal tracking circuits. Although 99% of manufacturers don't even mount the bias tracking "sensor" in the optimum place, so precision here doesn't make sense either.


----------



## RNBRAD (Oct 30, 2012)

I think the tolerance range of the components of a circuit probably depends on what your building the circuits for, the space shuttle or a Legacy amplifier.


----------



## ErinH (Feb 14, 2007)

LovesMusic said:


> So I will stress yet again, I dont have any indepth knowledge regarding amplifier operation but what I do know based on measuring tolerances in a circuit is that they fluctuate within the components spec'd tolerance. Each component has its own tolerance so this will translate to an overall deviation...
> 
> Looking at class d, it uses pulsewidth modulation of square waves which then is averaged or realistically speaking hypotenuced and filtered out to our sine wave. Surely knowing that there is circuit deviation, could this mean that each note in the dynamics of music will not be the same if measured..
> 
> ...


Well, in this case it seems we should be less concerned about class and more about quality control. No amp sounds the same anymore... Not even the same design.


----------



## ChrisB (Jul 3, 2008)

Hoye0017 said:


> So I'm confused. If that's your view on car audio amplifiers, why are you participating in a thread about differences in amplifier sound quality? If your requirements are noise free enough to not be noisier than your exhaust and better than stock, you could probably pick any amplifier on the market. Why spend the money on JL HD series?


I left out a few requirements because I had somewhere to be... They also must:
1. Fit under the driver's or passenger's seat. That rules out a TON of amplifiers.
2. Be reliable and not shut down or cut out
3. Meet my power needs
4. Not pop at turn on/off or HISS (unlike an Alpine PDX or 80s amplifier)

I used a HD900/5 in my Mustang and liked it, but I sold it with the car. I tried to use the PDX V9 in my new car, and that was a disaster. The moral of that story was "Buy cheap, buy twice!" So now it is either something that I already own, if it will fit where I want to install it, or a JL Audio HD series. Why? Because I know both will meet my needs and expectations for audio reproduction in the worst environment known to man. Besides, 99% of the time, changing out the speakers will net a greater result than changing out amplifiers rated for similar power output levels.

Since you think amplifier power supply topology makes such a HUGE difference in audio reproduction in the most hostile environment known to man... I have a question... What measurement between the two different amplifiers taken at the speaker leads when properly level matched causes you to think one topology is better than the other?


----------



## LovesMusic (Mar 29, 2012)

bikinpunk said:


> Well, in this case it seems we should be less concerned about class and more about quality control. No amp sounds the same anymore... Not even the same design.



Yes I see where quality control can become a great issue of hit or miss viewing amplifiers from this angle...



Markz does a class D circuit use a function generator of some sort, it must right.. does it hypotenise each pulse as its own frequency(guitar,bass,drum) or does it generate a function/pulse for the collective frequencies at any given second?



It is not hard to build an accurate simple circuit, even performing your own quality control, say a resistor doesnt spec out to a tolerance of +-5% then Ill simply grab another to spec out before it goes into the circuit. However no matter how tight I get these parts there is always deviation in calculations based on specs and measured... and lets say we just closed the circuit so temp is not affecting us yet. 

At every single note the class d amplifies there are im sure a ton of calculations processed much more then any class a/b. With every calculation or note isnt there deviation. I mean this is something that is a given so can we expect the more dynamic the music is the more deviation...?

What I was trying to explain before was say we have a kick drum and cymbal go off, then we have a kick drum and trumpet hit well can we assume the kick drum will not sound exactly the same based on the other frequencies it must share to the output. The kick and cymbal may play at a dif tolerance then the kick and trumpet.. any sense yet lol...
if so wed have to look at it this way... 

hook up to 2 o scopes slap a class a/b to one and class d to the other and play the same music on both watching their output on the oscope. I mean deviation could come at the amplitude the phase the slope and duration of every wave. I mean sure itd be a small small difference but could this translate to coloration...? 
of course a sine wave is based off all of these things and if it wasnt exact it wouldnt be the correct note, it would be a different note but as far as engineering goes these deviations no matter how small say 10 x ^-12 must play part into the amp charateristics...


In a push pull reciever I can see these tolerances being a HUGE part, one transistor is all it takes to deviate.


ChrisB I am no audiophile I am simply here for educational purposes and to "shoot the ****"... 
I chose my JL HD amps very much the same way you chose yours


----------



## MarkZ (Dec 5, 2005)

Yeah, class D uses a function generator of sorts as a carrier signal (think how radio works...). It usually operates >100kHz -- well outside the audio band -- and then this signal is filtered out at the end. The reason it's so efficient is because it allows the transistors to operate in saturated mode, where they're most efficient and where they tend to operate in the vast majority of circuits. In class A/B, B amps, there's a lot of loss that comes from the transistors just sitting there and dissipating energy. In class D, they're either on or off.

Anyway, there's nothing particularly special about lots of instruments playing all at once. It still forms a SINGLE voltage that changes over time. That's what you see on your o-scope. If you add another instrument to the song, you _literally_ add the voltage to the other one, leaving you with still a SINGLE voltage that changes over time.

So, no matter how many instruments or how "complex" your music is, it's still just a single voltage that changes over time. And so the "computations" that a class D or class A/B amp performs are no different, no matter what.

The accuracy of the amplifier can be measured. The most straightforward way to do this is by subtracting the input signal from the (attenuated) output signal and looking at what remains. You can do this with a very simple analog circuit, or you can do it digitally on a computer (you'll get roughly the same answer either way if you do it right). If there's no remaining signal, then the amplifier is faithfully reproducing the input signal, and there will by definition be no audible difference. David Hafler showed this 30 years ago.

If there is a remaining signal, we can analyze its properties, so that we can quantitatively describe the amp's accuracy with its frequency response, distortion, and noise, and how those things change under different circumstances.


----------



## subwoofery (Nov 9, 2008)

thehatedguy said:


> Someone just posted a link to the one I have.
> 
> Parallel single ended tubes in class a. Mine is 30x2, they have a 40x2 too.


Seems like they released a 45x2 version  
http://www.hssfidelity.it/it/prodotto-ht245-amplificatore-a-valvole-classe-A-2-45W

Kelvin


----------



## DrFred (Jan 19, 2013)

Just to another 2 cents - if you check audiophile magazines for high end class D amp reviews - even at the very top end the class D's are not considered to be quite the equal of high end class AB amps . It's said that they are getting very , very close though . Check out the Calyx 500 review in enjoythemusic.com to see what I am talking about . 
In car audio with all it's compromises - it's not surprising that some folks are very happy with their full range class D's . Does that mean they sound better than class AB's can - not necessarily . Given top end equipment for each class the AB's are still ultimately, a better SQ amp at this point . Will that remain the case - who knows ?


----------



## WRX/Z28 (Feb 21, 2008)

DrFred said:


> Just to another 2 cents - if you check audiophile magazines for high end class D amp reviews - even at the very top end the class D's are not considered to be quite the equal of high end class AB amps . It's said that they are getting very , very close though . Check out the Calyx 500 review in enjoythemusic.com to see what I am talking about .
> In car audio with all it's compromises - it's not surprising that some folks are very happy with their full range class D's . Does that mean they sound better than class AB's can - not necessarily . Given top end equipment for each class the AB's are still ultimately, a better SQ amp at this point . Will that remain the case - who knows ?


:cwm8::icon_bs:

Audiophile magazines... there's a scientific source not biased by pixie dust and advertisers...


----------



## ChrisB (Jul 3, 2008)

Damn, all this commenting and I didn't even add my own class ab versus class d comparison, as I did it in my vehicle just a few months back. At first, I was running a Lunar L100x2, 495 x 1 @ 4 (rebuilt to L2125 specifications after a beer incident), bridged to a Digital Designs single 4 ohm 1508. Next up on the docket, was a Lunar L1500, 500x1 class d, powering a Digital Designs D2 1508. Want to know what I noticed between switching out the subs and amplifiers? NOTHING! Yeah, that's right, no audible difference between the two.

I win, you lose, thanks for playing class ab versus class d wars with me. 

EDIT: I did notice less drag on my electrical system. With the class ab amplifier on the sub, I could experience as much as a one volt drop when cranking it up. Now, the most I get is .1 to .2 volts of drop. IMHO no audible difference with an increase in efficiency is an EPIC WIN!


----------



## avanti1960 (Sep 24, 2011)

ChrisB said:


> Damn, all this commenting and I didn't even add my own class ab versus class d comparison, as I did it in my vehicle just a few months back. At first, I was running a Lunar L100x2, 495 x 1 @ 4 (rebuilt to L2125 specifications after a beer incident), bridged to a Digital Designs single 4 ohm 1508. Next up on the docket, was a Lunar L1500, 500x1 class d, powering a Digital Designs D2 1508. Want to know what I noticed between switching out the subs and amplifiers? NOTHING! Yeah, that's right, no audible difference between the two.
> 
> I win, you lose, thanks for playing class ab versus class d wars with me.
> 
> EDIT: I did notice less drag on my electrical system. With the class ab amplifier on the sub, I could experience as much as a one volt drop when cranking it up. Now, the most I get is .1 to .2 volts of drop. IMHO no audible difference with an increase in efficiency is an EPIC WIN!


quite honestly there are not too many debates about class D vs. class AB when it comes to subwoofer duty. 
some will still argue one way or the other but they are in minute numbers- compared to those that believe the real issues lie within the midrange and high frequencies. The debate rages about amplifier class vs. sound quality in these ear sensitve frequencies for midrange and tweeter duty.


----------



## t3sn4f2 (Jan 3, 2007)

DrFred said:


> Just to another 2 cents - *if you check audiophile magazines for high end class D amp reviews *- even at the very top end the class D's are not considered to be quite the equal of high end class AB amps . It's said that they are getting very , very close though . Check out the Calyx 500 review in enjoythemusic.com to see what I am talking about .
> In car audio with all it's compromises - it's not surprising that some folks are very happy with their full range class D's . Does that mean they sound better than class AB's can - not necessarily . Given top end equipment for each class the AB's are still ultimately, a better SQ amp at this point . Will that remain the case - who knows ?


Ahhhh, the authority in which the ignorant are led astray or become part of the illusion.


----------



## ChrisB (Jul 3, 2008)

LovesMusic said:


> There was a question mark in there smart ahhh...
> 
> You really get off on this huh...Explain yourself instead of coming off as an ahole..No reason to rub it in my face if you know something I dont....internet or not.. how old are you again?


Damping factor was first introduced as a spec to tout superiority of solid state amplifiers over their tube counterparts. That's it. Somewhere along the way, some clever marketing department equated damping factor to SQ. This myth has been propagated and re-propagated as the holy gospel when in fact most can't tell the difference in audio reproduction when it comes to damping factor numbers over something stupid low, like 50. There is a test buried somewhere on the interwebz but I don't feel like looking for it right now.




LovesMusic said:


> BTW your the guy that came into my JL HD noise thread talking about how youve run many JL HD class D amps and they are surely not causing the noise distributed to my AM/FM radio, with some look at this chump attitude...
> It was confirmed by JL that they do. and are.


Link to post please because I surely don't remember stating this, EVER. You sure you aren't mixing me up with someone else?


----------



## DrFred (Jan 19, 2013)

Hey t3sn4f2 - Are you meaning to imply that all audiophile articles are part of a " myth " that humans can hear differences between components ? Because that is rubbish . It may be that " you " can't or it may be that the quality of car speakers and general car audio environment make it very hard to hear but that doesn't mean it isn't there .


----------



## MarkZ (Dec 5, 2005)

DrFred said:


> It may be that " you " can't


Golden ears.



> or it may be that the quality of car speakers


Golden wallet.


----------



## avanti1960 (Sep 24, 2011)

MarkZ said:


> Golden ears.
> 
> 
> 
> Golden wallet.


Golden years

David Bowie - Golden Years - YouTube


----------



## Richv72 (May 11, 2012)

DrFred said:


> Hey t3sn4f2 - Are you meaning to imply that all audiophile articles are part of a " myth " that humans can hear differences between components ? Because that is rubbish . It may be that " you " can't or it may be that the quality of car speakers and general car audio environment make it very hard to hear but that doesn't mean it isn't there .


I have had alot of cheap amps and speakers when I was a teenager and I could tell the difference when I bought good quality stuff. Its a night and day difference.


----------



## t3sn4f2 (Jan 3, 2007)

A fool and his money are soon parted. Nothing wrong with that since the fool will be happy at the end, and thats all that matters. Just don't let the fool think it's ok to spread his ignorant bliss without someone saying something about it.

Buy your $200 sneakers, but expect to get pooped on when you claim it gave you mad jumps yo!


----------



## t3sn4f2 (Jan 3, 2007)

Richv72 said:


> I have had alot of cheap amps and speakers when I was a teenager and I could tell the difference when I bought good quality stuff. Its a night and day difference.


"Cheap", "When I was a teen". "Its a night and day difference".

I don't even know where to start. Wait, I know.........

:cwm8:


----------



## Sound Suggestions (Dec 5, 2010)

Richv72 said:


> I have had alot of cheap amps and speakers when I was a teenager and I could tell the difference when I bought good quality stuff. Its a night and day difference.


Hi, don't waste your time...there's 5 or 6 members here that just keep coming back, 5999 of their 6000+ post are based on amps sounding the same....I gave up a long time ago on this thread, I have heard a fairly substantial difference between amplifier and logic tells me that using completely different parts/boards/power supply/caps...will yield a different sound in the end

:snacks:


----------



## LovesMusic (Mar 29, 2012)

ChrisB said:


> Damping factor was first introduced as a spec to tout superiority of solid state amplifiers over their tube counterparts. That's it. Somewhere along the way, some clever marketing department equated damping factor to SQ. This myth has been propagated and re-propagated as the holy gospel when in fact most can't tell the difference in audio reproduction when it comes to damping factor numbers over something stupid low, like 50. There is a test buried somewhere on the interwebz but I don't feel like looking for it right now.



Ok, I gathered what Info I could at school about it but..
Damping factor is a function of qtc and hz.

If we looked at damping on a specific hz we would see damping occur before and after the sine wave. Dare I say like a form of reverb... 
anyway given the manufactures specs for the particular damping factor at (X) hz, we could put this into a formula and measure a specific damping factor at any hz wed like. 
The speakers qtc will also play a big role in the formula and will be a variable to the damping factor. 

This is surely spliting hairs and I dont feel like searching the internet for formulas or any more information on it but surely when a example of a dampened sinewave was drawn in front of me I made a connection to it.


----------



## subwoofery (Nov 9, 2008)

LovesMusic said:


> Ok, I gathered what Info I could at school about it but..
> Damping factor is a function of qtc and hz.
> 
> If we looked at damping on a specific hz we would see damping occur before and after the sine wave. Dare I say like a form of reverb...
> ...


Yes damping factor can be calculated or measured but that doesn't mean it's an important spec... What _ChrisB_ has been trying to say is that damping factor really is worthless as a spec to compare 1 amp to another... 

Kelvin


----------



## LovesMusic (Mar 29, 2012)

subwoofery said:


> Yes damping factor can be calculated or measured but that doesn't mean it's an important spec... What _ChrisB_ has been trying to say is that damping factor really is worthless as a spec to compare 1 amp to another...
> 
> Kelvin



I dont believe it to be an "important" spec, I understand what ChrisB has been trying to say 3 pages ago..

More specifically, draw a dampened sine wave... accurately factoring in phase and amplitude of the damping factor at so and so hz and I see what I believe is means of coloration...
Basically the amp is telling the speaker to reproduce a hz with dif amplitude before and after the intended "Hz" is played...correct?


I guess The question that remains is how do these dampened sine waves translate in audio from one amp to another, Saying they dont, is not a solid justifying answer when I explained what I see when I draw a dampened sinewave on paper..

If it doesnt explain why..


----------



## subwoofery (Nov 9, 2008)

LovesMusic said:


> I dont believe it to be an "important" spec, I understand what ChrisB has been trying to say 3 pages ago..
> 
> More specifically, draw a dampened sine wave... accurately factoring in phase and amplitude of the damping factor at so and so hz and I see what I believe is means of coloration...
> Basically the amp is telling the speaker to reproduce a hz with dif amplitude before and after the intended "Hz" is played...correct?
> ...


Just don't worry about it  
http://www.diymobileaudio.com/forum/1387415-post5.html

Kelvin


----------



## MarkZ (Dec 5, 2005)

LovesMusic said:


> Ok, I gathered what Info I could at school about it but..
> Damping factor is a function of qtc and hz.
> 
> If we looked at damping on a specific hz we would see damping occur before and after the sine wave. Dare I say like a form of reverb...
> ...


This article explains why damping factor in modern amplifiers is irrelevant. Output impedances are low low low.


----------



## Hanatsu (Nov 9, 2010)

All these amp threads and they always end up with people arguing about the audibility of the amp's damping factor... ^.^

Sent from my Samsung Galaxy 3 via Tapatalk.


----------



## xtremevette (Apr 14, 2011)

Hanatsu said:


> All these amp threads and they always end up with people arguing about the audibility of the amp's damping factor... ^.^


I hear ya...whether or not it is relevant I just think and approach it with common sense. Does it really matter Class A/B/D/G/H? Of course. But with technology changes happen. Class D definitely has it's niche right now. Small compact, super efficient and most of all cheap as far as watts/cents! Just what 90% of people purchasing gear for their car want. Whether or not they actually sound better/different vs Class A/B I think will all come down to the person listening to it. I mean if you had 2 judges side by side blindfolded and turn on the Class A/B amp and then the Class D you'll more then likely get 2 different opinions on how each sounds. Just so many variables when you couple that will different amps even though they are the exact same make and model into the mix. I personally think it really shouldn't matter, if you like A/B then get an A/B, if you like a particular D then get that. The car audio shops have such a perfect weapon to get buyers into their shop but yet seem to fail to recognize it. How about advertising online...WE HAVE THE GEAR YOU CRAVE! DON'T GO BUY SOMETHING ONLINE BEFORE YOU HAVE SEEN, TESTED IT AND HEARD IT YOURSELF. This will get the buyer into the store. Once in they should be pushing...HEY WE CAN PRICE MATCH BEST BUY OR ANY MAJOR COMPETITOR What ya say?

Anyways though, back on subject...I think the comparisons are great and all, but people should realize they should be going out and having their own comparison. More information is better to the consumers.


----------



## LovesMusic (Mar 29, 2012)

MarkZ thank you, informative. No arguing its proved by formula.



Now Im about to open a can of worms saying this, and Im prepared for the lashing I may recieve but I agree 100%...
So lets hear it right...

Anyway I go to an engineering school here in NJ(for mechanical), and I decided to pick one of my professors brains on the amplifier subject.

His credentials, BS in EE from Stanford and a Masters in Biomed Eng. 
And for those that believe those who can not do teach. He made his money in 5 yrs with motorola and the silicon valley boom, then settled down over here with family and designed his own line of self help kiosks..

I proceeded to ask him a more generalized question, given same power ratings, no manufacture boosts in FR, do amplifiers sound alike?

He asked me my side & thoughts and I informed him of this sonic signature I believe in and that theres a crowd telling me this can not be.

He smiled and drew a picture of a string tied at both ends on his board(so much easier to explain through a drawing so bare with me), he then said if I pull this string down and release we can expect the string to rebound back up and hit a "positive" amplitude before it continues to its resting position.
If we pull the string harder the string will exhibit a "full wave" 360* plotted on a line then back to its resting position. If were able to pull the string even harder it will complete its full wave + another negative phase or 180*.

This brought him to vibrations. He then began to explain **IMPORTANT PART**
That once our signal passes through a DAC or we are in an analog signal we introduce vibrations and resonant Hz that are not present in digital state componants. These vibrations resonant Hz's are directly correlated to the output transistors. I asked is this on a quantum level? or can these transistor vibrations be measured? He told me its close but definitely can be measured.
In fact these vibrations/resonant Hz's of the components are then affected by AIR + Amplifiers Casing. Given the vibrations are in the componants once analog signal passes through, it is then further affected by air space and material (Larger scale think of what we do in a car). He said he likes using wood but then again that would be a perfect world and we wont see an amplifier encased in wood. Whether "you" are able to hear this or not it is there. 
He followed this with, though by changing the diaphram we will yield the most dramatic differences...

I guess have at it...but theoretically nothings the same 



I just hit my dad up and asked his thoughts as an EE... he said put an oscope to an unmatched output transistor in the amp chain and tell me its not a kink in the line...
Regardless of scoping the amps output. 


My thoughts Again this will be a matter of hearing "it" what does "it" even sound like but it is there..


----------



## WRX/Z28 (Feb 21, 2008)

So which sonic signature is best? How much do the different ones cost? If I want to listen to an acoustic guitar and have it sound like a live performance, which sonic singature should I purchase? 

Can one of you guys that know that amps all sound different tell me which one will make my recording of an acoustic guitar sound more like a recording of an acoustic guitar? 

Are better sonic differences more expensive to build? Should I just purchase the amplifier that costs the most to ensure that I'm getting the best sound?

:bash: 



*sorry for the excessive sarcasm


----------



## Randyman... (Oct 7, 2012)

WRX/Z28 said:


> Can one of you guys that know that amps all sound different tell me which one will make my recording of an acoustic guitar sound more like a recording of an acoustic guitar


Sound on Sound conducted a controlled comparison of a ton of different mic preamps last year. They mic'd a REAL PIANO that has a "player system" set up so each and every recording was identical (except for the preamps).


Forum - Main Forums : Recording Techniques

They pretty much came to the conclusion that all preamps (amplifiers in their own right - primarily voltage amplifiers) sound strikingly similar when operated in their linear range (sound familiar?  ). They used the "blind results" type test where they posted samples but weren't labeled - so it was a blind test for an entire online community!

I'll admit I've dropped thousands on Mic Preamps - but more for the build quality, overdrive/clip characteristics, and for the appeal and "clout" 

Swap a mic (a transducer) - and it's a WHOLE different ballgame...

I still believe all amps are not created equal - but I am surprised by how much they can sound alike in their linear range...

An aside - There are not any "Class D" Mic Preamps - I guess there's no need as the power requirements are practically nill (only need voltage gain, but LOTS of it!)...


----------



## LovesMusic (Mar 29, 2012)

WRX/Z28 said:


> So which sonic signature is best? How much do the different ones cost? If I want to listen to an acoustic guitar and have it sound like a live performance, which sonic singature should I purchase?
> 
> Can one of you guys that know that amps all sound different tell me which one will make my recording of an acoustic guitar sound more like a recording of an acoustic guitar?
> 
> ...



Cant say I didnt ask for it...

Although, while I may believe what I may hear as a sonic signature. I dont believe either hypothesis mentioned what can be called a "certain" sound. 

Simple answers, no they do not sound the same, given said variables. Nor is one said to be or sound better. It applies some particle and simple physics...

I..think this can only further a concern for (x) manufactures QC, like bikinpunk brought up earlier. However emphasis can be placed on component quality/design when manufacturing and price point are a factor. Furthermore I believe the word "better" to be non scientific and is soley based on application.

Lol, following the brief amp talk the professor and I start talkin about speakers and hes like how about a speaker which radiates and regulates its surrounding dispersion air temperature, thats where your heads gotta be!


----------



## MarkZ (Dec 5, 2005)

LovesMusic said:


> MarkZ thank you, informative. No arguing its proved by formula.
> 
> 
> 
> ...


You should start hunting around for a different school. 





> I just hit my dad up and asked his thoughts as an EE... he said put an oscope to an unmatched output transistor in the amp chain and tell me its not a kink in the line...
> Regardless of scoping the amps output.


Yup, push-pull stages of any kind should be matched. If they're not, you WILL see it on the output.


----------

