Hi and thanks; I replaced the speaker, cleaned everything I could get to without pulling the boards out. The noise still remains. The rest of the amp functions are working and it will get very loud but it's ear piercing at high volume.I wonder if it would be OK to try a transformer after the amp output chips? I know Peavey used them on some of their SS amps?

Quote from: blackcorvo on July 17, 2025, 07:24:07 PMI was perusing this thread on DIY Audio about the chip amp I'm using:

https://www.diyaudio.com/community/threads/fasten-seat-belts-tda8932-pessimistic-review.277130/

And people there mentioned cutting out issues related to overheating and over voltage, so I got adhesive heatsinks to see if it'd help.
Nothing.
I then tried using a variable PSU I have to see if a stable 12v or under would work.
And... For a moment, it did. Even got a bit overdriven in a nice way.
But as soon as I tried recording, it stopped and went right back to cutting out.
So I'm completely clueless to what might be causing this issue.

I think I'll just put a TPA3118 in there and call it a day, as I've had no issues with that amp in the past. I even have one in a repurposed modem case, that I use as a PA for testing pedals and preamps.

For now, I'll give it a couple days to see if anyone else has any idea of what I might be missing.

[Edit]
One last thing I might try is adding soft clipping at the PA's input.
https://sound-au.com/articles/soft-clip.htm

How did you try to add a heatsink to that amp ?
Many of the modern low power D class amps use the PCB as a heatsink, the IC has a heat pad on the bottom of the IC that touches the PCB.
Often there are a hole bunch of vias or sleeved holes under the IC to transfer the heat to the bottom surface of the PCB which is flood filled with copper to provide a heatsink, in that case it might be best to place a heatsink under the PCB with some insulating double sided tape.

It might seem strange that you don't place a heatsink on the IC itself but if the heat is being directed down and through the PCB itself then the heatsink has to live on the back.

I don't know if your amp needs the heatsink on the IC or on the back of the PCB but it is something to think about, feel the IC and the back of the PCB as the amp is heating up.
Cheers
Mick

I was perusing this thread on DIY Audio about the chip amp I'm using:

https://www.diyaudio.com/community/threads/fasten-seat-belts-tda8932-pessimistic-review.277130/

And people there mentioned cutting out issues related to overheating and over voltage, so I got adhesive heatsinks to see if it'd help.
Nothing.
I then tried using a variable PSU I have to see if a stable 12v or under would work.
And... For a moment, it did. Even got a bit overdriven in a nice way.
But as soon as I tried recording, it stopped and went right back to cutting out.
So I'm completely clueless to what might be causing this issue.

I think I'll just put a TPA3118 in there and call it a day, as I've had no issues with that amp in the past. I even have one in a repurposed modem case, that I use as a PA for testing pedals and preamps.

For now, I'll give it a couple days to see if anyone else has any idea of what I might be missing.

[Edit]
One last thing I might try is adding soft clipping at the PA's input.
https://sound-au.com/articles/soft-clip.htm

I have heard high frequency like that on those small portable Yamaha digital amps. Perhaps something to step up to high voltage but low current.

I don't think this is the case but I remember playing around with led strips that put out a high pitch noise. To make it worse the person using these led strips was putting them as guides on their guitars fret board. The power source has to be put somewhere where it won't pick up the frequency. But that Yamaha modeling amp put out this constant noise and it sounds similar to the high voltage/low amperage led strips. They use DC batteries to invert back to AC which stepped up to 100v. Maybe that Yamaha modeling amp didn't have a little noise gate to get rid of the high pitch when idle? Perhaps your amp has a gate? I would clean up the pots and switches as well. Justin Case.

Do you think this is how it sounded when new?  Doesn't the clean channel also use the FX board?

As with everything, practice makes perfect.

On na boring Sunday afternoon you can spend some time reading *all* those resistors and then confirming (or not    ) with a meter.

Even better, get a plastic box with 10 or 12 divisions, and group them by value, say 1-10 ohm, 10 to 100 and so on.
Not "one division per value" but next time you need one, you check the matching sub division and you know at least you are in the ballpark.

Also: at a glance you know you do NOT have certain value, instead of each time wasting 30 minute going through all of them again and again.

One of my laboratory exercises required a 22k ohm resistor 

Up until now I haven't really been a fan of the color code system but I think I really like it now.

Because honestly it stuck out like a sore thumb

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So yeah now I think it's a cool system but I have a much better time of looking to see what colors I need and then looking for that rather than trying to decipher faded colors trying to figure out what they are 

And then the four color to me is kind of a can of worms 

Hi and thank you; I did try a diff spkr and the sound seemed slightly better but not great.I tried changing tone settings and found improvement in the Clean Ch. The OD channel still sounds below par. May be the quality of the ICs on the separate pcb for the Digital Effects?

It started out like geddy and ended up like geezer 

Yes sir thanks after watching that I remembered so many times waiting for what seemed like an eternity for solder to melt.
especially outside sitting there sweating or whatever
Or the solder melts and it's this big blob that sticks to the tip and it refuses to go where I want it to so it's like a booger on your finger you can't get off   
Also wow I also used to think that every soldering iron tip had to look like an ice pick 
(I know somewhere those ice pick tips have a purpose but idk what it is)