# A little Pepsi Challenge, perhaps?



## ryan s

Got an amp here, let's discuss it. This isn't a "trap" where I'm posting a $500 amp with ugly guts so we can dump on it...no ulterior motives involved. 

It's a brand you've heard of, but it's not sold in chain stores like Best Buy. This is not some weird amp they only made 50 of...so no surprises. By all accounts, it IS a *cheap *amp. 

So tell me...what's good and what's bad about it? Put this section to good use  All traces (is that what they are?) are solid with no weird jumpers.

I think that's adhesive around the caps. It's not sticky and I believe it came like that. The amp works fine...no pops or anything. Can someone confirm?

Should have uploaded them elsewhere for a bigger size, but here goes anyway:










*Looking into the power section:*









*Looking into the "input" section:*


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## Lanson

This is why we constantly have arguments about modern amps really not being a big deal these days. There is a consistent decent quality product flowing out of China / Korea and most people won't have issues even with low-cost amps. Of course, they may be VERY overrated so if you buy the biggest/best of the low-end, you can expect it to perform about as good as the mid-end of an average amp.


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## ryan s

This one is a little older, made in Korea, and is labeled "Competition"... 

I've had no issues with it and it's strong. I'm just wondering about the vast empty spaces, and the white caps...or whatever those are  Also, another amp I have has a "resistor farm" where most of the resistors are in one spot, while this one has them spread out.

Not looking for an argument...curious about the technical side of things


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## benny

Yup, thats an amp alrighty.  the white "caps" are emitter resistors for the big 3 legged thingys under those clamps at the top.


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## chad

I like the way the inputs are mounted as to not be able to break them off the circuit board. The pots are kinda Meh, at least they will be easy to clean. It's an awful lot of heatsink on both sides to have the finals and PS mounted to one side


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## ryan s

I didn't even picture the empty space at the top above the "big 3 legged thingys" as benny so eloquently put it :laugh: There's about 2" of nothing up there. It's a decent size...almost 17 x 9".

...we're looking through the top of the amp. The heatsink is on the bottom  The sides of the amp are just to support the connection blocks and the top, like the walls of a house.

Now, I've seen transistors and FETS clamped parallel to the board (this one), at 45 degrees (old school PGs) and perpendicular to it (lots of others). Any inherent benefits from one way to another? Besides space considerations...


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## chad

Depends on how it's mounted, electrons like to run downhill therefore it changes the way they are biased. Sound/electrons are heavy, that's why kickpanel speakers (especially LF drivers) generally sound better because the amp is higher in elevation and the sound is running down hill.


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## ryan s

So roof mounted amps should give mad deebeez right?  Let gravity take care of those heavy bass molecules...


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## chad

Absolutely, ever wonder why amps are so heavy? They have all those electrons in them that you need to send to the speakers.

Go pick up a rack of crest pro 01 series sometime, you will leave your balls on the floor.


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## ChrisB

Why does that amp remind me of a product manufactured by Epsilon Electronics?


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## dualmono21

looks like a magnat amp to me


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## ryan s

I know the brand, no idea on the maker.

That was, technically, the fun part about the thread


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## gymrat2005

looks a little like those old Soundstream Edge series amps as well.


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## putergod

fourthmeal said:


> This is why we constantly have arguments about modern amps really not being a big deal these days. There is a consistent decent quality product flowing out of China / Korea and most people won't have issues even with low-cost amps. Of course, they may be VERY overrated so if you buy the biggest/best of the low-end, you can expect it to perform about as good as the mid-end of an average amp.


I disagree... I bought a chinese made amp, before I realized that SS had been bought out by Epsilon, and 6 months later it blew a resistor off the dang board.

Chinese made amps are freaking GARBAGE!

My American made amps, even the ones from the early to mid 90's, still work perfectly!
Got a few American made home amps from the mid to late 80's powering my home theater setup currently... and work great!


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## sqshoestring

That looks so Power Acoustik, or insignia, or kole, or SPL, or...or...or.... ChrisB nailed it.

They work, but look at the cheezy tiny clamps and screws. That one actually has screws in the board, most of them don't the transistors have to hold the board until they break. Those bus bars blow right out of the board once in a while, the outputs blow a lot but I have no idea what use they had. I bet 20+ other amps use the same design, though that is not always a bad thing. It is a very typical cheap China amp I've seen too many of them. Unfortunately a guy here loves to buy them from me so I was doing them for some time. The insignia like that is rated around 2x115rms at 4 ohm.

I mean you get what you pay for, when they work they seem to work ok and the kids that buy them can beat them senseless so hard to judge too far. I have one here right now they blew the gain off the board, some 400lb moose with a screwdriver I suppose....or maybe just an idiot.


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## mxer657

Interesting reading this. I can tell this is a relatively inexpensively made amp but I'm not anywhere near the level of all of you who can pin point certain things


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## db-r

The traces are only on the bottom of the board and it's full of jumpers. It may be cheap but since 99% of all modern amplifiers are the same inside whether they look different to the trained eye or not doesn't matter, they are all the same/similar. It's cheap but it probably sounds great. I don't care for single sided PCB's but lots of lower end, lower power amps use single side PCB's, have for decades. 

Probably a Clarion or Eclipse amp.

The white thingies are not caps, they are big resistors, emmitter ballast resistors. 

Funny watching people try to interpret what's in an amp, I get a real kick out of it, I don't know everything, of couse, but component identification is the easy part, so if you screw that up, then LOL, good luck with the rest...


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## db-r

ryan s said:


> All traces (is that what they are?) are solid with no weird jumpers.



LOL because what you are calling "traces" are in fact just DRAWINGS of traces printed onto the board, basically what you see on top is a drawing that is a mirror image of what traces are on the bottom of the board.


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## steve

db-r said:


> LOL because what you are calling "traces" are in fact just DRAWINGS of traces printed onto the board, basically what you see on top is a drawing that is a mirror image of what traces are on the bottom of the board.


I don't think so. 

The "lighter" blue parts are actual traces (possible ground plane) on that side and from the way the they are clearanced around the through holes and the lack of connections on the visible side to the transistors and other parts I expect most of traces are on the other side, so it's at least a double sided PCB. You can see in several of the pictures where the board is soldered to those traces like in the last picture at J21.


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## caraudioguru

Single sided board. Lots of jumpers. Bi-Polar output with 4 devices per channel (may be a mono amp, but really a stereo amp bridged) Large core (T750 Amperex it looks like) wound decently. Not enough capacitance. 8 FETs for power supply , probably IRFZ44's would be my guess. Very typical Chinese built amp. Not enough copper on the board , that's why the copper tubing looking stuff jumping current. Looks OK. Nothing to write home to Mom about 

Bill of Materials, under $50, should retail for about $250 max...

Just a guess......


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## caraudioguru

The "sticky" stuff under the large capacitors in the power supply area is to keep the caps in place under vibration (mounting to sub-woofer box for example). This is so they don't break the solder joints of the axial lead caps. Done many different ways. This is one way.


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## db-r

steve said:


> I don't think so.
> 
> The "lighter" blue parts are actual traces (possible ground plane) on that side and from the way the they are clearanced around the through holes and the lack of connections on the visible side to the transistors and other parts I expect most of traces are on the other side, so it's at least a double sided PCB. You can see in several of the pictures where the board is soldered to those traces like in the last picture at J21.


No it's definately single sided PCB. Those are drawings, not traces. The solder you see poking through around that hole in the last pic is simply solder on the other side of the board showing through a hole cut in the PCB where something could be added to the board for a different model but is not present on this model.


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## db-r

caraudioguru said:


> Single sided board. Lots of jumpers. Bi-Polar output with 4 devices per channel (may be a mono amp, but really a stereo amp bridged) Large core (T750 Amperex it looks like) wound decently. Not enough capacitance. 8 FETs for power supply , probably IRFZ44's would be my guess. Very typical Chinese built amp. Not enough copper on the board , that's why the copper tubing looking stuff jumping current. Looks OK. Nothing to write home to Mom about
> 
> Bill of Materials, under $50, should retail for about $250 max...
> 
> Just a guess......



Pretty sure it's a 2 channel. And fets are likely DFP50N06, or DFP70N06 outputs are likely Sanken 2SA1694/2SC4467 or 2SA1695/2SC4468 or possibly KTB688/KTD718 or TIP35C/TIP36C. These are all common in Korean made class AB amplifiers, so it could be any of those. 

And it definately looks Korean not Chinese. Most likely the Heatsink costs as much or more than the whole board with all components inside installed on the board, and probably build cost (cost to "_____ amp company") is likely around $75-$80 per amplifier and it probably sells for $250-$350 new in the US.


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## Therum

Good: Uses buss bars, Discrete 15v reg (Looks like it), Nicely wound torroid.
Bad: More capacitance on the 12v side, No RC network to shut ringing. (It may be there but cant tell. I see a mylar cap but no flame proof resistor. Jumpers and 0 ohm resistors out the wazoo. I have came across a sonus amp that looks just like this one. Pyle? or same manufacturer.


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## db-r

Therum said:


> Good: Uses buss bars, Discrete 15v reg (Looks like it), Nicely wound torroid.
> Bad: More capacitance on the 12v side, No RC network to shut ringing. (It may be there but cant tell. I see a mylar cap but no flame proof resistor. Jumpers and 0 ohm resistors out the wazoo. I have came across a sonus amp that looks just like this one. Pyle? or same manufacturer.


Most Zenon amps have nicely wound transformers. This amp is old Zenon stuff, lower line, single sided PCB amp. 2 x 100W @ 4 ohms.

Where did you see a 15V regulator? It uses 2 flame proof resistors and some Zener diodes for 15V+/- for the op-amps in the input circuit just like the current Zenon amps use, no seperate regulators. Maybe you mistook the two TO-220 case rectifiers near the power supply mosfets for regulators, but no, those are just 16Amp rectifier diodes. Power supply voltage is likely 28-36VDC+/-

What ringing? I don't understand what you mean an RC circuit to prevent ringing, there should be no ringing if the correct gate resistors, pulldown resistors and a decent drive circuit are used with the TL494 IC.


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## db-r

ryan s said:


>



Actually, considering the low amount of current on the rail of this amp at it's recommended impedance loads, 4 ohms per channel or 2 ohms MAX per channel this IS enough capacitance to smooth out power supply ripple. I agree nothing wrong with overkill on rail capacitance except, that when you first turn on the amp, there is a great surge involved in charging LOTS of rail capacitance, and it could potentially cause premature failures of power supply mosfets. Look at all the large rail caps in the old DD Z1 amp. When those things start up with caps drained, they pull tremendous amounts of current just to start up and charge all those caps. Granted the old amp doesn't sound that bad, it definately has overkill on capacitance. 

Only way this amp MAY need more rail capacitance would be if you were running subwoofers with it at 2 ohms per channel, it might help it a little to have a little extra capacitance there on the rail, but would be an easy upgrade, even for a novice to do to change those caps to 4700uf or bigger. Might have to buy some expensive compact sized caps, but they can be had, and relatively cheap.


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## Therum

True. I was speaking of B+ caps. I have seen a PPI DCX amp that ran 46v rails I believe with much less capacitance. In the picture above. I now notice the flame proofs with the zeners. So what are the to-220s that are sticking up right beside them? As far as the RC network I think they are called snubbers.


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## chad

db-r said:


> Actually, considering the low amount of current on the rail of this amp at it's recommended impedance loads, 4 ohms per channel or 2 ohms MAX per channel this IS enough capacitance to smooth out power supply ripple. I agree nothing wrong with overkill on rail capacitance except, *that when you first turn on the amp, there is a great surge involved in charging LOTS of rail capacitance, and it could potentially cause premature failures of power supply mosfets.* Look at all the large rail caps in the old DD Z1 amp. When those things start up with caps drained, they pull tremendous amounts of current just to start up and charge all those caps. Granted the old amp doesn't sound that bad, it definately has overkill on capacitance.


Mah Brotha! Preach on. people look at these things after looking at home/pro audio amps and forget that said caps are charging WAY WAY more often in a car amp.


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## Luke352

chad said:


> Mah Brotha! Preach on. people look at these things after looking at home/pro audio amps and forget that said caps are charging WAY WAY more often in a car amp.



Haha, nothign like seeing 20000uf of caps behind a 2 x 25 watt chip amp, as you scratch your head and go, why? As the builder spoofs on using his entire dialogue of snake oil terms.


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## Therum

Hey, That makes it hit harder. LOL


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## Robin W.

Not that it means anything either way, but the Alpine PXA-H700 that I'm working on right now if full of those "cheap looking" Sam Young capacitors. I won't say they are bad capacitors, just the application of the covering/labeling on many of them is sloppy compared to a Panasonic FC/FM or Elna Silmic II.


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## ryan s

Korean, A/B, 2 channel, ~2001 manufacture date, "MSRP" of $450 (lol), 100 x 2 @ 4 and 400 x 1 @ 4 and MAYBE 200 x 2 @ 2 but not sure...some bang-on observations in here 

Works and sounds just fine...has for years. 

Shall I reveal it?  Spoiler below...
































Drum roll...


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## mxer657

eh thats disappointing lol


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## theauricle

chad said:


> Depends on how it's mounted, electrons like to run downhill therefore it changes the way they are biased. Sound/electrons are heavy, that's why kickpanel speakers (especially LF drivers) generally sound better because the amp is higher in elevation and the sound is running down hill.


Bro, judging from your number of posts, I wholeheartedly PRAY that's just a joke.

-joe/theauricle


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## theauricle

caraudioguru said:


> ...
> 
> Bill of Materials, under $50, should retail for about $250 max...
> 
> Just a guess......



The BOM on this is under $18. Most of that is the heatsink/chassis.

If we built this at Flextronics, I could pirice 5,000 of them to you under $50 each. (FOB Penang, MY.)

The caps in there are complete trash, the PCB is garbage, and yet, the amp probably works 75% as well as my Zed Audio gear and PG ZX. (Until you crank it.)

-Joe/theauricle


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## Therum

Disappointing? I call it EXPECTED.


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## chad

theauricle said:


> Bro, judging from your number of posts, I wholeheartedly PRAY that's just a joke.
> 
> -joe/theauricle


Keep reading and realize that I have a rather unique sense of humor.

For example I have a pair of blue balls as my avatar.


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## ryan s

Therum said:


> Disappointing? I call it EXPECTED.


Exactly...as I said in the first post, it wasn't meant to be a "look at this ****ty amp...just kidding, it's really a ______!" thread. Just testing out the new Guts subforum :laugh:


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## GlasSman

Well it's safe to say that the output of the Chinese factories is _*MUCH *_better than it was in the early 90's....think Urban Audio.....Pyramid.

And that amp is what....6 or 7 years old?

It all depends on how much time and effort the company marketing the amps puts into final QC.


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## putergod

GlasSman said:


> Well it's safe to say that the output of the Chinese factories is _*MUCH *_better than it was in the early 90's....think Urban Audio.....Pyramid.
> 
> And that amp is what....6 or 7 years old?
> 
> It all depends on how much time and effort the company marketing the amps puts into final QC.


I still hate chinese craplifiers... Even the "good ones" are junk compared to a good, ole fashioned, hand made in the USA (or even UK/IT/DE), amp.


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## grinkeeper

Picture link is dead, What did this amp end up being?


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