# soundstream reference 500 repair help



## Camineet (Oct 20, 2011)

Hi guys,

I'm hoping I could get some help on my first repair project attempt. I have just now unearthed my soundstream reference 500 which I was fortunate enough to keep in very good cosmetic condition.

The amp failed after several months of use back in 96.

I've taken photos of the parts that I found inside that have burned up. The large overview photo of the guts has a red square which indicates the area that corresponds with the close-up photos.

From what I understand, what I'm looking at are fried resistors along with an adjacent bank of transistors with what appear to be a couple of fried ones on the right side along with what appears to be another fried one on the left side.

I've done some studying and have learned that resistors' specs are determined by the color striping on them. Since the resistors in my amp are completely burned up, I can't read the color stripes. Can I trouble someone to let me know how the spec of these resistors can be determined? I've looked online and can't find anything in the way of a schematic. But maybe you guys know where these kinds of things can be located. Or maybe someone knows of a high rez photo source that I have yet to be able to locate in my web search. At any rate, I'd really appreciate help getting started on this

I recently got started in the hobby of messing with old school amps when I unearthed a pretty unknown and obscure white amp that I happen to have in near-perfect condition and working. i bought it new and used it for about 2yrs in the late 90's, babying it all the while. I'm just now re-doing the thermal compound as my very first old-school amp project(last pic attached). really enjoying so far

I'm sure no one has heard of or seen this white amp before. It must not be a very good one:laugh:


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## Buickmike (Aug 10, 2012)

I hate to be the bearer of bad news, but unfortunately there is going to be a lot more wrong than just those resistors. If resistors are burned up that bad, it is due to something else shorting out that caused the issue in the first place. This is most likely one of the output transistors shorting out. It could also be a power supply transistor depending on where those are located. You probably also have fried leads as well since they are that cooked. That's a nice amp and honestly with that level of damage I would give it to someone who is recommended on here to repair it.

I had an amp with fried resistors way back in the day and replacing them just fried the new ones. I'm not familiar with the PPI's but am honestly surprised they don't have a protection circuit that would prevent this level of damage. 

Take this from a guy who repairs his own amps, but is a total amateur. I know enough to be dangerous lol, but I know enough to understand that those resistors did not get like that on their own.


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## Buickmike (Aug 10, 2012)

Nevermind, I see its a Soundstream. In pic # 8, you can see what appears to be a power supply transmitter (Q102) that has burned leads. It most likely is the culprit. I think there is an issue with Q104 as well. Honestly you are probably in for a couple transistors, the resistors, and some new leads on the board as well.


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## Camineet (Oct 20, 2011)

THANK YOU for reply much appreciate it

Actually, my first plan was in fact to send it to Zed.

It happens to be that I've become stuck in my present location waiting on something so I can do some extended travel. I need something to kill some time. all mly kiteboarding stuff is packed up and... i just wanna mess with this thing.

So, I decided I want to see how far I can get with this yet another hobby on top of all the other ones I have which I'm actually quite good at keeping under control cost wise.

I'd like to swap out those resistors and the bank of transistors to get started. if that doesn't work, i could look to up my game by getting educated on the things you mentioned or just give up and send it to a pro. These kinds of parts basically cost nothing and I recently upgraded all of my soldering gear so my kit has all the toys, which also cost very little. anxious to perform surgery with them.

i've built some of the best game controllers on the planet for guys over 40, and i did an electric mountainboard that went faster than is safe. would like to have a go with my old car audio gear

I figure I can find out the part number of the transistors pretty easy. I've seen guys on youtube do that without much problem. But incinerated resistors, I just can't read the color striping at all. Any ideas?


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## Guy (Feb 16, 2006)

Wade Stweart designed the amp and can probably help you out with the schematics. [email protected]


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## TrickyRicky (Apr 5, 2009)

Those resistors appear to be the gate resistors for the power supply mosfets. They range from 10ohm-100ohm depending on the characteristics of the fet. 

I have a 700s Soundstream so I'll take a look at it and give you exact values.

Be prepare to replace the PWM ic, all six power supply fets, six gate resistors, the fet drivers. 

Check each resistor for resistance, perhaps one of them is still intact and within tolerance (I believe they may be 33 or 47 ohm but can't remember from the top of my head).


Also if the power supply went out, something had to cause that such as one of the two channels shorted out/failed and cause the power supply to fail as well. So I would recommend checking the output devices on the amplifier side (TIP107 and 102's if am not mistaking).


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## soccerguru607 (Nov 4, 2009)

If you are thinking about sending it out to get repaired might as well have Ricky repair it for you. His excellent.


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## Camineet (Oct 20, 2011)

ok right on. thanks for guidance guys

emailed Wade.

will send to Ricky if efforts fail.

thinking is: i'll try incrementally replacing stuff until i haven't the confidence to try whatever's next. then it's a send-out.

for now, i think i can handle replacing resistors and transistors.

there may in fact be a larger problem that caused the burn up. I'm hoping it's just a matter of having taxed the amp too much when it was in use. I've never been wealthy, and back when I ran this amp, I didn't have anything in the way of a car audio grade alternator or even an upgraded battery. I have a feeling that if I just replace the parts that I see burned up, the amp will work. if not, i'm fine with trying whatever's next unless it's too hard. and hten i'll send it out.

i have to completely disassemble the amp in order to redo the thermal compound anyway. So, if it isn't too difficult and expensive to order some resistors and transistors, I might as well do that and replace them while the amp is disassembled and see what happens.

As far as the impedance of those resistors, I still need help with that. I took another look and did find that at least one of them on each side fo the capacitor bank is probably still good - the left-most one. I also found that the two sets of three resistors on either side of the capacitor bank are not all the same. The left-most resistors in each set of 3 are different than the other two. At least I think so. 

As seen in the attached pic, two of the three resistors are fried, and appear to be different than the leftmost one. I think that I was even able to identify the impedance of the leftmost ones as seen in the attached screenshot from digitkey's tool.

Anyway, still hoping to get confirmation on what the actual impedance of these resistors are.

I actually don't even own a multimeter because I've never done a project that required one. I'll get one if I have to. they're only nine dollars on Amazon


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## Camineet (Oct 20, 2011)

Just took another careful look over the whole board. All the other parts outside the problem appear to be in fine shape. No signs of scorching or anything unusual looking. No dark spots or anything like that. 

The capacitors even look good, although I understand I'm supposed to replace those anyway due to their age.


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## vwguy383 (Dec 4, 2008)

IMHO, I would think that most repair guys would like to have an untouched amp to repair. They are or amps and your free to do what you want with them. They are very nice looking amps and fine examples of old school power. Tricky can chime in if he wants, but I would say also that some guys might not want to put there name on a repair that has already been touched. 

It's like that auto shop poster that you see hanging in some repair shops as a joke

Shop rate: $
Shop rate if you watch: $$
Shop rate if you watch and tell me how to do something: $$$
Shop rate if you have worked on it already : $$$$

Something like that, but you get the point. I have always wanted to be able to repair amps myself too very interesting to me. But I have seen things go wrong after someone has put a lot time and effort to repair something, because ether didn't know to check something out and PUFF there goes all there hard work.

Thanks
Justin


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## Camineet (Oct 20, 2011)

that shop poster joke is hilarious. don't know where i saw that before, but it's a good one


i just have nothing better to do right now. this isn't really a practical or logical pursuit. come on guys, help me identify those resistors so i can make a move

oh, and thanks for complimenting the amps. i too quite enjoy having them. what i don't enjoy, is that they've been in storage for 20yrs. truth is, i may never own another vehicle for long enough to do a car audio system. closest i got was doing the big 3 in a '90 Sentra in SE asia 4 years ago. 

at this point, screwing around with them is the only real joy i may ever get. actually, the PPI is going to be the basis for my home audio system for my next overseas stay soon. i've got that project fairly well squared away:

https://www.youtube.com/watch?v=Py2SpSk0GYQ

i'll only be able to play it at low volumes in my apartment over there, but at least i can enjoy the use of it rather than just owning it which i can't abide anymore. i'm into the impending collaborative economy (access to things, not competing for ownership of things), work for a guy who does some pretty fancy consulting on startups, accelerators, and the coming disruptions in traditional business models. into experiences, not things. 

thanks again for replies. hope to make friends here as when i did other projects in other forums. these kinds of projects really work well for that


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## TrickyRicky (Apr 5, 2009)

Have you checked the mosfets? Am sure one if not all took a nice dump, you'll have to completely remove the pcb in order to take a look at them, but you'll notice the hershey squirts immediately upon removal.


I personally don't like taking in amps that have been repaired, recently did a Soundstream MC500 and had several damaged/lifted/missing pads and traces. If not carefull you can easily lift the pads on those pcb's doesn't mean that it can't be repair just takes a bit longer to fix so where it won't be noticeable.


If you just replace the resistors I can guarantee you that they will just pop/burn/toast up right away because you have bad mosfets. I'll get you resistors value here in a few minutes.


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## Camineet (Oct 20, 2011)

ok cool. thanks for some marching orders 

i'll research to learn wtf mosfets are, and check them. i wanted a timekiller, and now i've got one:laugh:

yes, i understand nobody wants to be responsible for dealing with the clowned up mess of some yahoo's tinkering

i'm just tooo much enjoying the possibility of getting this amp back into operating condition myself with the help of veterans generous with their knowledge.

they said nobody could solder onto the pinouts of PSP analog stick's flat cable. pfft...

look forward to what's next with this


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## TrickyRicky (Apr 5, 2009)

If you look up the data sheet of the PWM IC you'll see how they work, what each pin does and as well as a few simple applications that can be used with the ic..simply amazing information!!

Okay I looked at my SS that I have and they are 3.3ohm (see if you can get fuse-type so they don't cause damage if they do fail again). The mosfets are NDP7050 which may be obsolete so you'll have to go with IRFZ44, IRFZ46, IRFZ48 or IRF3205, however you will have to change the gate resistor value (the 3.3ohm that fried) to something higher like 33-47 if you plan on using the fets I mentioned. 

You also have drivers for the fets (these are between the 3.3ohm resistors and the PWM IC...pin 11 & 14 *again look at the data sheet and you'll notice all this info already listed there). The drivers are 2N2222 and 2SA1562 (two of each, one pair per side or per 3 fets).


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## ssclassa60 (Jan 28, 2013)

These are darlingtons, not mosfets (controlled by current as opposed to voltage)


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## Buickmike (Aug 10, 2012)

TrickyRicky, you are a class act helping out with that info!!

Camineet. Seems like you have a good handle on what you are in for with this amp, so as long as you plan to keep it for yourself, plug away until it works, and not count on passing it onto someone else to fix after you hacked it up, I say go for it!!!

I have also done my own amp repair and when I fix them I get a serious sense of accomplishment because I am a complete armature. My first attempt was to repair a Lanzar Optidrive Plus 100 that I had in highschool and broke a couple times. It would play music for 2 seconds and go into protect. I went down the total wrong road with this one and did not do the board any justice lol. I started with new caps, then pulled all the drivers and checked them all. Put those all back and replaced all the mosfets. Still no joy. Then I replaced the optocouplers to no avail. I let it sit for a year. One random day the lightbulb went on and I realized that even though I verified that the thermistor resistance changed with temp, I did not have a baseline for what the resistance was supposed to be. I also have an Optidrive 50, so I compared. The resistance on that one cold was 70. Way below my 100. I put a 70 ohm resistor on to test and voila! It works!. Replaced the thermistor and now it is solid. I have it pushing a couple MTX Blue Thunder 10's now.

This really gave me a good understanding of what is going on. I am in the process of repairing my Hifonics Europa VIII. It had a pop when powering on and the power LED would not light up. I found a small capacitor that was bad in the middle of the board and traced it to the LED, so I replaced it. It suppressed the pop for the most part and the LED came on, but then a few minutes later the amp went into diagnostic mode and refused to play anything. Testing it out I found out the pop was DC voltage bleeding to the B speaker outputs for a brief moment before going into diagnostic mode. I tested the output transistors and one was shorted. It feeds the B speakers. I pulled it and no more diagnostic and A channels play. I have a new one ordered. It should be back alive tomorrow. Here's to hoping you eventually have a success story on this one. Just take it slow, use a power supply or small battery with low amps, use a very low amp fuse, and make sure to replace all those mosfets with the resistors.


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## Camineet (Oct 20, 2011)

Buickmike said:


> TrickyRicky, you are a class act helping out with that info!!
> 
> Camineet. Seems like you have a good handle on what you are in for with this amp, so as long as you plan to keep it for yourself, plug away until it works, and not count on passing it onto someone else to fix after you hacked it up, I say go for it!!!
> 
> I have also done my own amp repair and when I fix them I get a serious sense of accomplishment because I am a complete armature. .


that repair story prolly put you into some kind of 'skilled' category. what an ordeal. you may not be certified or anything, but still


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## Camineet (Oct 20, 2011)

TrickyRicky said:


> If you look up the data sheet of the PWM IC you'll see how they work, what each pin does and as well as a few simple applications that can be used with the ic..simply amazing information!!
> 
> Okay I looked at my SS that I have and they are 3.3ohm (see if you can get fuse-type so they don't cause damage if they do fail again). The mosfets are NDP7050 which may be obsolete so you'll have to go with IRFZ44, IRFZ46, IRFZ48 or IRF3205, however you will have to change the gate resistor value (the 3.3ohm that fried) to something higher like 33-47 if you plan on using the fets I mentioned.
> 
> You also have drivers for the fets (these are between the 3.3ohm resistors and the PWM IC...pin 11 & 14 *again look at the data sheet and you'll notice all this info already listed there). The drivers are 2N2222 and 2SA1562 (two of each, one pair per side or per 3 fets).


thanks pal. i'm slowly going through this message line by line and doing some detective work to make sense of it. much of it is like a foreign language for me. 

discovered my socket set is missing the one needed to remove the board from the heatsink to check the 2SA1562's. i found the 2N2222's, but i'm guessing the 2SA1562's are on the underside 'cause i can't find anything with that kind of number on top near the 2N2222's.

have to get my amazon cart up to $49 to get that free shipping. should be a week or so...


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## soccerguru607 (Nov 4, 2009)

Google Perry Babin if you really want to learn how to repair car amps


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## wheelieking71 (Dec 20, 2006)

soccerguru607 said:


> Google Perry Babin if you really want to learn how to repair car amps


Jimmy is right. More reading than one guy with a full-time job could accomplish in a years time if he has perfect reading comprehension. I have lost myself in here many many times! http://www.bcae1.com/


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## TrickyRicky (Apr 5, 2009)

ssclassa60 said:


> These are darlingtons, not mosfets (controlled by current as opposed to voltage)


The output devices are TIP102/107's that are darlingtons...we are focus on the power supply section which utilizes mosfets, which is clearly where the problem is. Of course he needs to check the output devices as well as those could of cause the damage on the power supply section.


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## Buickmike (Aug 10, 2012)

Perry is a good guy and gave me a lot of advice on my first amp repair. The basic amp repair site is awesome too, but a ton of reading. Once you get hands on and understand basic amp functions, the site becomes less confusing and makes a great reference guide.


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## ssclassa60 (Jan 28, 2013)

TrickyRicky said:


> The output devices are TIP102/107's that are darlingtons...we are focus on the power supply section which utilizes mosfets, which is clearly where the problem is. Of course he needs to check the output devices as well as those could of cause the damage on the power supply section.



Understood, thanks for clarifying.

I had a DaVinci that had output device issues. Repair guy in UK walked me through the the fix. It was interesting to see how shorted transistors cause all kinds of collateral damage.


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## Camineet (Oct 20, 2011)

Hey guys, got an update on my plans. I am in fact planning to send the amp to TrickyRicky in about six months if he's still available.

I first have to manage to get overseas and buy a car, which will take some doing.

I might change my mind if some confidence comes and try to do it myself. But I think you guys have shown me a pretty good picture of what's involved, and I can foresee that it actually wouldn't be as fun to move forward as I originally thought.

Grateful for the advice here and also will much appreciate it if TrickyRicky will be so kind as to have a look at my amp down the road


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## TrickyRicky (Apr 5, 2009)

Sure...I don't visit here as often as I use to but I'll check in every once in awhile. If you do decide to tackle it we are here to help you out.


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## Camineet (Oct 20, 2011)

very fine


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## rockytophigh (Apr 16, 2008)

Send your amp to TR.....he's an upstanding guy who knows his stuff. He went through 4 Soundstream amps of mine and pricing to have a fully functional and tested old school amp is well worth it!!! He is the man IMHO.


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## Camineet (Oct 20, 2011)

yeah, i'm gonna.

1st have to get overseas, get settled in apt., get a car. it's a lot to deal with, but having a system in a foreign country is a dream of mine. 

i've gotten as far as doing teh big 3 in a '90 sentra in Phuket 5yrs ago.

can't wait to try again


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## Camineet (Oct 20, 2011)

hey guys a bit of good news for 90's car audio gear put into use

i scored an apt with thick concrete floors that allow for a bangin system in-home

so, i'm not just putting my ppi amp to use for an in-home system, but i'm also going to put the SS Ref 500 we talked about to use

the ppi will remain in use as seen here

https://www.youtube.com/watch?v=il2cGV_xQEg

and the soundstream will power 2 polk 12" dvc momos in a sealed box 

i'm loving this apartment and hope to stay a long time. it needs some room treatment as it sounds like a friggin gymnasium in here but...

gonna also add a 500w sony xplod 90's amp with 2.1 speakers as a kitchen system that will auto-power-on via motion sensor so the volume of whatever i'm listening to in the living room doesn't fall off as i stroll into the kitchen to grab a chocolate bar or make my lunch sandwich xD

got a request in to mom to ship the soundstream out to TR. hopefully she gets that done within a few weeks. then, mom and stepdad are visiting us here in Xiamen in Oct. i'm gonna have them haul 2 extra checked bags of the remainder of my 90's car audio gear. can't wait

might be nice to someday do a PC /w a proper audio card so that my signal isn't coming from a 7 cent microphone jack on an onboard mobo line-out but whatever. it works for now and the system as is sounds spectacular except for the 15 dollar sub enclosure tube seen in video. that POS was literally 15 bucks shipped here in China. about a week away from building a sealed enclosure according to polk specs for that 8" momo.

swear to god, tool buying here is heaven. anything with the obligatory 9.99usd price on amazon is like a dollar here /w another dollar ship charge. all the little doodads for a well fitted workshop that can run into hundreds just for the little doodads don't amount to much money. and the big ticket items like circular saws and jigsaws are like 20 bucks. just loving this


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## Camineet (Oct 20, 2011)

oh btw, i've learned that a parking spot downstairs costs 100k USD. so that sh*t aint gonna happen, and this is another reason why i've gone in the direction of setting up all my 90's car audio gear in home and have no plans or hope to have them in a vehicle.

oh well, i've worked at home for over 10yrs and don't really even leave the house for any reason other than social, fitness, and food shopping. sometimes i don't go outside for like 3 days in a row

best to just set up all my stuff where i spend most of my time eh


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## fuster (Nov 21, 2008)

I have a large Soundstream (the U.S. made amps from the original company) collection. I have had several of them rebuilt by Wade Stewart, the company founder. He just sent back a couple of my Reference 500 amps (I have nine of them) and a Reference 414s, all of which were converted to Class A design and a lot of board components replaced including electrolytic capacitors and the FETs. He sends them back with a graph of the performance of the amplifier at various loads and voltages. The output of all amps he has rebuilt went up from factory specifications. Very good work.


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## acelabs (Jul 27, 2014)

Camineet said:


> Hi guys,
> 
> I'm hoping I could get some help on my first repair project attempt. I have just now unearthed my soundstream reference 500 which I was fortunate enough to keep in very good cosmetic condition.
> 
> ...


I designed all of the old school SS amps. I don't know if your still interested but I can repair or rebuild all SS old school amps. If your interested or if you would like some help or need a schematic please message me.


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## acelabs (Jul 27, 2014)

Camineet, I designed all olf the SS old school amps. If you still need help I can answer any questions you may have or send you schematics for that amp. I can also repair or rebuild / upgrade all old school SS amps. Please message me if you need help.


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## nicksri (Jan 4, 2018)

My soundstream amp has pretty much of the same problem. Have you had your problem figured out?


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## acelabs (Jul 27, 2014)

I designed the Reference 500. The first reply was correct. If those resistors were burned that means that you have some bad moosfets in the power supply. I have included a copy of the schematic for that amplifier. The burned resistors are 3.3 ohms. If you would like any help with this repair please let me know. I can also repair, rebuild and upgrade your Reference 50.


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## acelabs (Jul 27, 2014)

sorry, my attachment didn't come through OK. Here it is again.


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## acelabs (Jul 27, 2014)

sorry, my attachment didn't come through OK. Here it is again.


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## Camineet (Oct 20, 2011)

hey guys thanks for the info and support on this project. 

last year i sent the SS Ref 500 to TrickyRicky and he managed to repair and return it to my home in MI after some trouble on his end causing a pretty long delay. it was very helpful of TR to do the significant work required in the end for a very reasonable price. i ended up having to give him a tip in BTC to try to fairly compensate him for how much work he had to do.

anyway, i will get the amp back in Dec this year when mom comes to visit us here in china. hope to power 2 12" polk subs here in teh apt which are currently powered by a cheap chinese amp i bought for $120 for the interim.

https://photos.app.goo.gl/wmOXQKusvuh0H2mu1

got a new problem. my PPI A600.2 turned out to need some work. some static can be heard when playing at low volumes. very annoying and needs to be fixed.

i tried recapping the amp myself, but the big caps were too difficult for me to remove. i managed to replace one of them and tested the amp. still works fine but i can't replace anymore of the caps. they're too difficult. 

i sent the amp back with mom to MI when she visited in Oct last year. the amp has all the caps needed to recap it together in MI. 

i need someone to recap the amp and try to diagnose the static problem and fix that. is there anyone here or that you guys can recommend for handling this particularly precious amp? the condition is probably 9 out 10.


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## SoundLunatic (Jul 2, 2021)

Hallo, sorry for opening old thread, but i need help with this reference 500 amp, i have burned power supply transistors and i dont know whitch model they are. Acelabs are upload pdf schematic but its damaged, i can see only output section. 

Thank you.


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## Camineet (Oct 20, 2011)

I found a guy on facebook called old school car audio restoration and am planning on sending my PPI a600.2 to him. I already sent it to the amp lab, and they couldn't fix the problem with distortion and it makes the amp unusable for mids/highs.


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## Txsaxkat (Jul 17, 2021)

Just got finished repairing a Zapco 1000.4 reference I bought at a pawn shop and someone just didnt treat it right. It worked for about 6 months noticed it would go into thermal after driving home from work 30 min drive it was hooked up to 2 sets of diamond audio hex sets with silk tweets. So it was the front left channel and it started to distort after warming up. Changed all of the mosfets and and such on front channel recapped it put some elna cerafines in the audio path and panasonic FC and nichicon for the rest it sound great better than before Driving DLS goth 3.0 in front diamond audio hex for rear fill. 1 IDQ 10 in the trunk / Eclipse 8052 HU. Never could get the DLS to sound good as I thought they should until this last repair had some monster patch cords and swapped them out they may have had something to do with it. I have a stack of old amp I need to fix 3 PG ZPA 0.5 zx 500 zx500.4 zx600 Xtant 1000.1D needs caps PPI MTX blue thunder pro. It does feel good when you finish a repair and it work! I was talking to trickey rickey about doing some repair year back on the PG forum and it stop posting busy man and seems like the real deal which is rare props go out to him maybe I will see if he will be available. I almost sent my zapco to desert audio for repair I think they are maybe good but maybe others can chime in on that back to my eclipse DA 7122 repair and my martin sax overhaul got to many things going at once. sorry about the rant but wanted to pitch the desert audio repair out their and get some feedback.


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## Camineet (Oct 20, 2011)

Tricky Ricky really did a fine job for me.


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## Txsaxkat (Jul 17, 2021)

Cool like your test bench well Im in the houston area and tricky ricky was in the dallas area last I talked to him on the PG board years back but he dropped off the board sure he had his reason and know how it is. I sent him a message. I love the old sound stream stuff Im running eclipse HU that have 8v outputs so I need the input voltage on my amps a little higher than 2.5 or 5 even. Cheers


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## Camineet (Oct 20, 2011)

right on. greetings from michigan. yeah TR got really busy and had a hard time finishing my amp. i think it took like over 6 months. hope he's alright these days.

i sent him 10 bucks worth of btc as a tip and it's worth a hundred now. tried to reach out to him to see if he had any trouble accessing it about 4 months ago but never heard back :/


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## Txsaxkat (Jul 17, 2021)

Thanks for the heads up maybe I wont hear from him.


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