Amp repairmen please halp!

[SSS 18734 5,000+ posts]

I managed to get my hands on this old school beaut yesterday - a Soundstream TR 880/2. Beast of an amp. It weighs 35 pounds, uses class A circuitry, and can apparently put out around 1000 wRMS bridged at 4 ohms.

The amp powers on and both channels run strong. The problem is, the amp squeals like supa's mom during bass hits. The higher the gain, the harder she squeals. It almost sounds like somebody is scratching their nails against a chalkboard, but higher pitched. Any ideas as to what is causing this? The board shows no visible signs of damage. The sound seems to be coming from this general area:

Click to read more...

 

[SSS 18734 5,000+ posts]

For god's sake, make that pic smaller and don't quote my entire post! I will go douse the amp with WD-40 right now. Hopefully that will do the trick.

 

[Shinju 10+ year member]

Output/powersupply is going tits up!

Not long till it goes poof!

 

[Supergumby5000 5,000+ posts]

ddeeerrrttttyyyy siigggnnaaalll

try another amp in its place? To me, it just sounds like a signal issue, either being a bad RCA, ground loop, or a muffed up RCA terminal on the amp.

or the PS may be crappin out. My autotek whined before the power supply went out, but it wasnt obnoxiously loud or anything.

 

[ciaonzo 5,000+ posts]

Transformer?

 

[ThatChevyGuy 5,000+ posts]

wiggle the rca's slightly on the amp, don't break them though.

That board reminds me of my old lanzar.

 

[Shinju 10+ year member]

ddeeerrrttttyyyy siigggnnaaalll
try another amp in its place? To me, it just sounds like a signal issue, either being a bad RCA, ground loop, or a muffed up RCA terminal on the amp.

or the PS may be crappin out. My autotek whined before the power supply went out, but it wasnt obnoxiously loud or anything.

I had 2 old Fosgates do this I got them used and didnt get a chance to test them right then and there.

Hooked them up and ran them, Played just fine but I could hear this god awful noise comming from the amplifier its self.

You could hear distorted audio coming out of the amp with no speakers hooked up to it.

a few weeks later.... Dead. Had them repaird and it was the output/Powersupply that was on its way out from being ran hard under their impedence.

 

[Shinju 10+ year member]

On a good note though I think Soundstream has a flat rate fix policy on stuff so you can probably get it fixed for 150.00 ish. Might even get a new board too.

 

[SSS 18734 5,000+ posts]

Any idea on how much it would cost to replace the power supply, if that is indeed the case? Would it even be worth it? This amp used to be expensive back in the day, but I have no idea what it's worth now.

 

[ThatChevyGuy 5,000+ posts]

http://www.db-r.com

free quote

 

[Shinju 10+ year member]

Fully working ones still sell for about 300-400, Yeah it is worth it those are nice amplifiers eveny by today's standards.

 

[scanlines]

The squeal is most likely from one or more of the toroid transformers.

Turn the thing on, then push down on each transformer until you found the culprit (s)

I let them run and wiggle the culprit Xformer until it stops whining then, RTV it (silicone) to the board.

 

[Grinder1989 5,000+ posts]

The squeal is most likely from one or more of the toroid transformers.
Turn the thing on, then push down on each transformer until you found the culprit (s)

I let them run and wiggle the culprit Xformer until it stops whining then, RTV it (silicone) to the board.

x2. That's not always true, it could be a powersupply issue but if the amp is running and not getting abnormally hot, then I'm sure its just a whiny transformer. No big deal really.

 

[gotparts90 10+ year member]

i hope to god you dont actually put wd40 in ur amp.

no shit that is one of the few bad uses for wd-40 it is hell on electrical varnish.

 

[Mass Car Audio 10+ year member]

The squeal is most likely from one or more of the toroid transformers.
Turn the thing on, then push down on each transformer until you found the culprit (s)

I let them run and wiggle the culprit Xformer until it stops whining then, RTV it (silicone) to the board.

If the transformer is making a bad noise, it could be the power supply transistors sending a bad signal to the primary winding on the transformer.