# how do i know if its the RCA input on the AMP?



## burakol (Apr 25, 2008)

i have a bad feeling that one of the RCA input on my amp is flawed... 

although i still get sound out of it... it is somewhat distorted in nature and a very low whine is coming out.... i tried switching the rca's but still had the same effect so im thinkin its not the rca cable...

may it be the RCA input itself? or should i rewire and use another cable? 

this is not the 1st time i've installed a simple system in my car and never had the issue in the past... the amp is SS Ref700...


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## ollschool (Nov 21, 2008)

I had the same thing happen a while back, after checking everything and swaping cables. It was the outputs of my headunit, Do you have a spare you can wire up to check it if all else fails. Does this happen on both inputs.


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## burakol (Apr 25, 2008)

just one input. i think its just channel 2... channels 1,3,4,5 sounds clean... i'll try another amp then... or i will use the rear out of my deck instead of the front outs.. if that fail then ill try a different amp...


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## burakol (Apr 25, 2008)

how come the distorted sound only comes out in my tweets? i tried hooking up the mids on the same channel where im having the funky noise but there's no distortion/whine... 

could it be the tweets then?


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## burakol (Apr 25, 2008)

how can i validate if its the RCA input on the amp that is causing the distorted sound? anyone? thanks!


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## db-r (Apr 20, 2008)

The only way I know to check that is to take the amp apart, remove the RCA stalk, check for broken legs... I don't recall if the SS Ref series has a stalk or if it has the fancy panel mount inputs... But either way, if you at some point accidentally touched a 12v+ wire to the RCA Shield behind your head unit or at the amp (doesn't matter where it touched) it could have burned a PCB trace up in the amp for the shield.


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## burakol (Apr 25, 2008)

sound is coming out on that channel.. its just i hear some distortion and whining sound... i made sure the power and the rcas are not near each other... grounded all components properly... 

i will try to open it up and see... i will also try and change the RCA cables... its just frustrating that after weeks of doing my 1st custom install, the end product was not what I expected...


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## aztec1 (Jun 13, 2008)

Muting plug


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## burakol (Apr 25, 2008)

aztec1 said:


> Muting plug


sorry but im not too technical.. would you expound further? 
if theres one downside of me doing car audio.... that is, i am seriously having a difficult time understanding the technical side of it... 

i enjoy building and working on installs, but when it comes to the tuning etc, im no good...


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Hold on with the opening things up a little... it's not going to tell you squat unless you knew what you were looking for and those amps have some of the best RCA inputs in terms of strength, of the sort... you just can't get any stronger than that... so, possible, but not very probable... 

EDIT: expanding on muting plug above ^^^ 

A mute plug is a cheap ass RCA connector, cut from a old playstation 1..lol..or something, where you take the cable and strip it back and short it together... so you literly short the input to ground... 

I would first pull the RCA's all together, and use the plug... if the amp comes though fine, then i'd be looking at the RCAs or the HU

The sound you hear, is it RPM related to the car in any way? If so, I would try re-grounding the HU, again, before you start opening amps up... 

You could also try a different RCA ran over the carpet, to test if it's a pinched cable... 

Are the amp crossovers configured correctly and do you have all the speakers wired to the proper outputs...? 

What sort of gain set-up did you do? 



> how come the distorted sound only comes out in my tweets? i tried hooking up the mids on the same channel where im having the funky noise but there's no distortion/whine...
> 
> could it be the tweets then?


You must be running it active, if you are swapping mid for tweet, are you SURE the settings are correct? I know that amp, it can be confusing even if you know them... You said Ref700, but you also said 5ch's, so, you mean the 705 correct? Great amp....


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## burakol (Apr 25, 2008)

yes it is the 705... it took me time to think about the setting and yes it was confusing in sorts... i set it up as to run in 3 way mode to get the active setting for the xover since my HU is not active capable... 

for the whinning sound.. yes it is RPM related... so that for sure is a grounding issue... 

but for the distored sound... i have no clue... but i wil try to run the rcas over the carpet and see... i already had a bad feeling on those since it was a recycled ones from an older install on my previous car... 

as for the gain its over 1/4 but not over the half way mark...


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Yeah, re-ground the HU, first... did you use the factory harness ground? If so, you might want to try grounding right to the body. if not, you might wanna try the harness ground.. lol... 

Get some different, cheap RCAs and run them over the carpet and see... 

Make up a mute plug first though, you can easily and quickly tell if it's the amp that way... Those amps rocked, but at the same time could be very delicate... they earned the nickname "SmokeStream" for a reason... this doesn't sound like that though... just keep your subs at or above 2ohm... running 1ohm is asking for it, even if it states it's not a problem...


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## burakol (Apr 25, 2008)

For the mute plug... so i butcher an old RCA connector... this is basically the female part of the RCA (correct)... loop the wires together as if im jumping it and grounding both wires up... then what?

yes, i just did use the factory harness plug.. i did use a new harness connected to the factory but basically, the grounding point for the HU is the ground line of the stock harness...


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

burakol said:


> For the mute plug... so i butcher an old RCA connector... this is basically the female part of the RCA (correct)... loop the wires together as if im jumping it and grounding both wires up... then what?
> 
> yes, i just did use the factory harness plug.. i did use a new harness connected to the factory but basically, the grounding point for the HU is the ground line of the stock harness...



You can use a connector, you need the male, to plug into the amp, but all you are doing is shorting the center pin to the case... or the 2 wires if it's a cheap molded plug type... cheaper the better, it's just a very simple tool..

So, you might want to try grounding the HU to the body... sometimes grounding the case of the HU can help as well.... you simply losen a screw on the case, place a thin wire under it and tighten it back up,... ground that somewhere, make it a good clean paint free ground... try to get it on the tranny tunnel or firewall or something... grounds are getting worse and worse these days... hell, you might even try grounding it to the battery... all grounds are NOT always the same...


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## burakol (Apr 25, 2008)

found an old thread about the mute plug... ill try to make them tomorrow and see... hopefully i can then isolate the real cause... but just in case... worse comes to worse and the amp is the problem... would this be an easy fix???


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## db-r (Apr 20, 2008)

Something else simple you can try without taking the amp apart, is to take a screwdriver, just any kind with a shiny metal shank, and lay it across the Shield from one of the "good" RCA's to the questionable one, if no luck then problem may be in the amp. If it's a 4 channel go from 3/4 to 1/2. This connects the shield from the 3/4 channels to the shield on the 1/2 input channels and see if the noise goes away...


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## burakol (Apr 25, 2008)

sure will.. i will keep you guys updated.. thanks!


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## less (Nov 30, 2006)

I'd be VERY careful when removing the cover of the amp and trying to get to the board. If you've not done it before, its easy to break a wire or switch in the process, because of connections that you can't see, or mounting screws that aren't as visible as you'd like. 

I've built home amplifier and pre-amp kits and torn apart a lot of electronic gear over the years and I accidentally destroyed my ADS 8 channel when just removing the cover due to a switch that I accidentally snapped off the board - couldn't replace exactly and then had issues with soldering a new one to the board... so please take care.

Did I read that this noise issue only took place if the channel is connected to a tweeter? If so, that makes is pretty questionable that its and amp problem... did you try it with another tweeter? Are you 100% sure you don't have a driver problem?

Not knowing this specific amp, I do know that a noise issue is much more likely to come from an RCA cable than from a broken amp. One of the best ways to isolate an issue is by swapping wires with a PROVEN set of RCA cables taken from a working installation and left completely exposed (not reinstalled in your mounting locations) to avoid any pinch issues. Yo may well be past this point already but I can't quite tell from the conversation here... its good to know anyhow though!

Start by removing all of the old RCAs coming from your hu to your amp. Then, plug in one pair of rca cables - being sure to include the reportedly bad channel of the amp and the possible bad channel on the head unit. Turn it on and listen for noise? No noise - then get new RCAs and your good to go. Still noise - then your RCAs are probably fine. 

Next - swap your two RCA channels at the head unit end only. Noise moves? If so, the issue is somewhere with your H/U - if noise stays the same, the issue is with something to do with the amp and you now know at least where the problem lies! If the issue is your amplifier and its an older one, you might try totally disconnecting it and then using some high quality contact cleaner on all of the switchs on the unit. Once you spray the switch, then manipulate it on and off several times rather roughly to help remove any corrosion and help the chemical by giving it some physical pressure. Don't go too crazy with the cleaner and be sure to let the unit sit unplugged for 24 hours to assure that nothing gets shorted. 

While grounding issues are certainly major noise makers... it seems unlikely that a ground issue would only impact one channel. If you have alternator variable noise, its likely a seperate issue, but deserving of attention. Grounding issues can be a major pain to track down. I first suggest doing the big three (or 4 if you have a civic) as that is a MAJOR improvement for many vehicles... especially older vehicles. The big three made major improvements for me and I'll do it to any car I get in the future as well - system or not. Be sure to check for a fuse in the line from the alternator to the battery and install one if you have one there on the stock line too. If you can't do that make sure you have clean connections where your stock cables meet the body - block and battery at the very least! 

Just try cleaning up various places where you have a nice possible connection to a solid body part, starting your own new self threading screw and listen until you get clear of the trouble... and be sure to recheck the connection a couple days later to make sure its still tight.

Anyway, I'm sorry I couldn't contribute more, but either I didn't read well enough or there just wasn't enough information for me to make a better analysis. Either could easily be the case because it is still too early for me to think lol!

Good luck!
Less


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## Mooble (Oct 21, 2007)

It's not hard to replace the RCA jack. You can do it with very minimal soldering skills. It's also very easy to see the RCA jacks on Soundstreams. They are nice and airy inside. Soundstream uses the "flying buttress" type of connectors. Look to see if one of them is broken. The problem you are describing could very definitely be caused by a broken connector on the jack. The difficulty will be in removing the board. Soundstream mounted all the fets between the heatsink and the board. You will need to unscrew nearly a dozen screws to pull the board out and resolder the jack. Jacks are easy to find. Go to someplace like Mouser Electronics. You can buy them for under $1.

Just open up the amp and look for a broken connector. You should be able to open it up and tell in under 5 minutes.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Mooble said:


> It's not hard to replace the RCA jack. You can do it with very minimal soldering skills. It's also very easy to see the RCA jacks on Soundstreams. They are nice and airy inside. Soundstream uses the "flying buttress" type of connectors. Look to see if one of them is broken. The problem you are describing could very definitely be caused by a broken connector on the jack. The difficulty will be in removing the board. Soundstream mounted all the fets between the heatsink and the board. You will need to unscrew nearly a dozen screws to pull the board out and resolder the jack. Jacks are easy to find. Go to someplace like Mouser Electronics. You can buy them for under $1.
> 
> Just open up the amp and look for a broken connector. You should be able to open it up and tell in under 5 minutes.


 
Agreed, but not till AFTER some troubleshooting of the RCA cable and HU... 

With the way SS RCA inputs are it's so un-likely... not saying it's not possible, but it's slim... 

I've teken them apart and it sucks... the worst part is the LED indicators, they are just bent into place and often get mashed in the mix.. lol..


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## Mooble (Oct 21, 2007)

Aaron'z 2.5RS/WRX said:


> Agreed, but not till AFTER some troubleshooting of the RCA cable and HU...
> 
> With the way SS RCA inputs are it's so un-likely... not saying it's not possible, but it's slim...
> 
> I've teken them apart and it sucks... the worst part is the LED indicators, they are just bent into place and often get mashed in the mix.. lol..


Yep, SS uses some of the strongest connectors I've seen. It may be a hard connection, but it's extremely sturdy. Linear Power used some very weak and crappy connectors on the LP and DPS series that are only held fast by one screw. It's very easy to snap those.


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## burakol (Apr 25, 2008)

schools over and im going home now... im in no mood to stay behind and do some after school activity... need to solve this issue quick!!! 

ill let you guys now... for now, i'll start with the muting plugs...


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Even WITH the muting plug, my vote goes to re-grounding the HU...


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## burakol (Apr 25, 2008)

ok so here are my initial results after swapping RCAs and re-grounding the HU and amp...weird thing is, I noticed that when I turn off my engine but the radio and amp is still on, the distortion goes away... here's what I found out so far...

i did use a new pair of RCA cable I have laying around... used different power cables and ground cables... 

When engine is running:
1. RCA is not connected to both amp and HU - no distortion coming out 
2. Both ends of a new RCA is connected to the HU and AMP - distortion comes out
3. One end of the RCA is NOT connected to the HU but one end connected to the amp - distortion comes out
4. Used the mute plug on the AMP - no distortion coming out

When engine is off but key is on ACC
1. Ends of the RCA connected to the HU and AMP respectively - no problem
2. Only one end of the RCA is connected to the AMP - no problem
3. Using mute plug - no problem

When engine is off but key is on BATT
1. When both RCA ends are connected to the HU and AMP - problem comes out
2. One end is only connected to the AMP but NOT to the HU - problem comes out
3. Using mute plug - no problem

I also opened the amp and here's what I saw on that problem RCA input... haay... any thoughts?

FYI.. my deck is an alpine CDA-9830


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## db-r (Apr 20, 2008)

Your amp has the cheapy plastic RCA stalk, not the old fashioned ones I thought were always on the old ref series... You likely got a broken shield leg from your RCA stalk to the main amp PCB.


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## db-r (Apr 20, 2008)

You can confirm it by doing my screwdriver (or a small peice of wire) test, placing a wire or other electrical conductor across the outside part of the RCA jack while it's plugged in, from say, channel 3-4. If that does nothing, try it with all 4 RCA's plugged in and jump across from 1-2 to 3-4 with the wire and see what happens. I thought you had said it was a 4 channel amp, but if it's a 2 channel then just jump from 1-2. Don't ground your RCA shield to the car though, bad idea...


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## burakol (Apr 25, 2008)

its the 5 channel 705s... its not the older 705...

i only took the pic of the problem rca..

so wait.. what you are trying to say is jump the outside part of the RCA jack to each other?


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## burakol (Apr 25, 2008)

db-r said:


> You can confirm it by doing my screwdriver (or a small peice of wire) test, placing a wire or other electrical conductor across the outside part of the RCA jack while it's plugged in, from say, channel 3-4. If that does nothing, try it with all 4 RCA's plugged in and jump across from 1-2 to 3-4 with the wire and see what happens. I thought you had said it was a 4 channel amp, but if it's a 2 channel then just jump from 1-2. Don't ground your RCA shield to the car though, bad idea...


its either i did it wrong or it just made no difference... after i opened up my Old REF200, now i see the difference between the material used in the 705s... yeah its plastic compared to the metal used in the Ref200... 

i have a bad feeling its the amp... 
but how come when the car is on ACC there's no distortion coming out from the amp? its only when the engine is running or if the key is on the BATT position...


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## less (Nov 30, 2006)

It seems to me you have an issue with your grounding and not the amp. If in any scenario the amp functions fine, its something else. Since the issue doesn't happen when its on acc - and does when its on Batt, I think you should look VERY CLOSELY at how you have routed your signal wires. Something is running when its on BAT and ON that is generating noise through your RCAS - or so I suspect. I had the strangest noise at one point that went away when I moved one wire literally less than one milimeter from the position that it naturally rested in! Wiggle your installation wires and if the problem pops off, there is your trouble... reroute the offending wire and your problem likely goes away. Of course, there may be more than one offender... so isolate and test... step by step through the entire installation.

Good hunting =) Its an odd situation, but its likely to be something simple and at least while it will cost time, it shouldn't cost much in terms of money! 

Less


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## burakol (Apr 25, 2008)

when I was fidgeting with the ground, here is what I found out...

When I changed the grounding location of the amp to at least 3 different spots, making sure all are bare metal, nothing changed...

When I changed the grounding location of the HU and directly to the car... the distortion sounded less but still noticable and very annoying! 

Would a going bad battery have any effects as well? My battery is like 2 year old and I see some oxidation starting to build up on the top of it...


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## burakol (Apr 25, 2008)

db-r said:


> Your amp has the cheapy plastic RCA stalk, not the old fashioned ones I thought were always on the old ref series... You likely got a broken shield leg from your RCA stalk to the main amp PCB.


how much would it likely to cost me to have it repaired?


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## db-r (Apr 20, 2008)

Assuming the problem is the RCA connector shield from the stalk to the board, not much really. Repairs are billed by time spent (labor time) though unfortuneately it may take 2 hours to repair start to finish including load testing and all that, so you would be looking at paying the Class AB repair rate of $40 / hour + shipping costs. It's really something you could probably do yourself... Or if the amp is worth alot of money and you are really scared you will mess it up (how much is that thing worth anyway as I am not familiar with the newer SS series, only the really old Ref series like the 300, 300S, 500, 500S etc) you can send it in for repair, but if it takes me two hours to take it apart and repair it, even if it's just a bad solder connection on the bottom of the board I MUST get paid for my time... just the way it works... Same thing as if a mechanic works on your car for half a day to change a $10 part... It would be much less expensive to repair it yourself if it's a simple prob.

However, I think the problem may be in your car, you said the noise goes away with Key on ACC, but with key on BATT it is there... Sounds like some interference from something electrical in your car. Lots of times it can be the alternator, or the fuel pump (electric pumps), Electric cooling fans (engine fans), A/C Fan, Ignition System, door is open buzzers etc...

Try the amp in someone elses car to see what is up, and try their amp in your car. If the problem is the same in their car, it's your amp, if the problem goes away it's a problem with something in your car.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

burakol said:


> its the 5 channel 705s... its not the older 705...
> 
> i only took the pic of the problem rca..
> 
> so wait.. what you are trying to say is jump the outside part of the RCA jack to each other?


The 705 and the 705s are respectively a model year apart.. so the design is basically the same... 

And CRAP, I just looked at my pics of the 705s that I had and they DO have the chincy RCA connectors on them.... son-of-a-*****... 











This is more like what the "good" SS RCA jacks should look like... lol..


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

I've had a few SS Ref's... 



















^^^ There WAS another 500 to go with the above, it was in parts, stripped and ready for paint.. lol..


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## burakol (Apr 25, 2008)

see... this is not the 1st time i installed a system in this car.. before this i had 2 RF punch installed under the front seats and all was perfect... no unwanted noise at all...

this time, i am putting the SS amp in my trunk and i noticed that the top cover of the fuel pump is also visible from the trunk near the amp... 

is a going bad battery also have any dreadful effects??? 

if i am to do the RCA stalks shiel myself, would you mind letting me know how to??? i do know how to solder but i just don't know which components to touch... PLEASE???

Thanks!

>>>> Aaron <<<< 
my wife's car in the philippines have the 644s and 700sx which until now has not proven to be a "smokestream"... 
right now i have a ref200 and this 705s... 
i just love these amps... i don't think i'll ever use anything else provided that they work fine... but then again, if i had the extra dough it may be a different story...


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## burakol (Apr 25, 2008)

ok.. i again tried to trace the problem... i ended up trying my spare a300 art series and hooked it up... the sound was clear as water.... no distortion/whine at all!!! i used the same RCA cable that i ran to the car.. same grounding point as with i used for the SS amp... grounded the HU via the stock harness... in short, i did nothing special and just hooked it up... result was, problem was not evident.... 

so..... do i now conclude that the one RCA input on the SS amp is bad? 
how do i get to fix the RCA shield stalk? i opened the amp a while ago to closely check for any burnt/loose solder but all else looks clean...

i actually sprayed on some lube over the switches and will try again tomorrow if that will make a difference... 

any thoughts? amp or something else???


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## burakol (Apr 25, 2008)

db-r said:


> It's really something you could probably do yourself...




any tips on how i do about it? i did opened up the amp last night to do a visual check of the soldering and all seems intact... was there something not visible to the naked eye that can only be seen if sent to a shop for repairs?


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Damn man, that sucks... quick question, is the amp mounted to metal on the car, or on a board? Sometimes a ground loop can be created, through the amp chassis.. 


Yeah, doing the proper re-soldering on that amp would a real *****, because most of the actual soder "blobs" are on the side of the board you CAN'T see... and it's a real bugger to tear down and put back together.. propery.. 

If you don't know much about soldering, then, this isn't the amp you want to test your skills on... 

You got something that is garbage that you could practice on first, because I CAN think of a way for you to "re-flow" the solder, but it's usually best to apply a little as that is done.. 

Do you have a soldering iron? If so, is it good condition? 

This is a little snippet from a install tutorial I did on another forum, just to get you pointed in the right direction... 



> Now, the SOLDERING LESSON....
> First and for most, it needs to be HOT, the hotter the better, plug it in before you begin and by the time you are ready to use it, it'll be GOOD and HOT...
> Next, the soldering iron needs to be in good shape for good soldering, NEVER, NEVER file or sand a soldering tip to clean it... once hot, a damp paper towel or sponge "should" clean it, if it is in half way decent shape... If you can't get a nice bright silver/chrome look from it, consider some fine seel wool, if that doesn't do it, a new tip or iron...
> Now, you need to "tin" the iron, which is nothing more than melting some solder in the tip, this needs to be done often to keep a thin layer of solder on the tip. The tinning acts as a conduit for heat transfer. Clean the tip often on the damp whatever you have and re-tin after each cleaning...
> ...


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## burakol (Apr 25, 2008)

i just got back in from testing the amp again.. this time, i installed it in my brother's car... DAMN!!! it had the same problem!!! 

i tried his on mine and another spare amp i had and no issues at all... 

i guess its really a bad input huh??? 

AARON: thanks for the soldering tips... i gutted out the amp last night and fortunately i was able to put it back together... cleaned the inside with some lube hoping it would make a difference today but none... i really didnt see any bad solder on both sides of the board... or should i say, i really can't determine which is good and which is bad... all seems to be in an ok shape... 

how does a ground loop work???


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Hold up, what did you clean up on the amp?? The white grease stuff??? If so, DON'T continue to use the amp.... 

That white paste is heatsink paste and NEEDS to be there.. if you removed that, you need to go to a Radio Shack and buy a small tube and re-paste all the MosFET's like they were.. 

So, something is definitely up with the amp.. you doing what you did shows that.. 

If you had the amp taken apart, did you see anything out of the ordinarily..

The reason I never really think/thought it was a solder is because they use a 4 layer board, heaver than most and stronger.. so, much less likely to have bad solder... 

Now, bad solder can be a well defined crack or removal of the trace from the board altogether, or it could be a very thin ring around a terminal you can't hardly notice.. Again though, with those boards, it very difficult for any of that to happen... 

Ground loop... http://www.bcae1.com/ topic 126 on the right of the page... goes through it a lot better than I can.. 

I donno man, i've never repaired one of them myself, you may try pointing the member here Envisionelec to this thread and see what he says, though he's a very busy man, and I hardly ever see him post... I could be in the wrong sections though... He's repaired a few or more now, including most of the ones you saw above I had on the wall... as he owns them now...


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## burakol (Apr 25, 2008)

i just cleaned the board itself.. not the thermal paste... i know those had purpose... thanks for looking up though... i did not see anything out of the ordinary... what i thought was al seems to be intact... board was perfect.. solders seems fine... none at all

i may just end up sending it to a shop... there's one thread in this section about SS repair shops... i'm also waiting for db-r's reply if i can send him my amp... hopefully it is not going to cost me much more than the current value of the amp...

just disappointing... after im done with all my setup and all... i now this amp worked flawlessly the last time around so i didnt bother to check before i did my install and everything...


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