I was using the batteries directly - unprotected batteries, too - for my tests, so power was very clean, and saw no voltage drops with signal. And I tried the preamp on a separate power supply, both with the PA on it's own PSU and on batteries - same cuttting out result.

Also, just as an "insanity test", I went reading up on the DIY Audio thread again, and it seems like TDA8932T has presented issues for other people too, and they had better luck using the BT variant of the chip instead. Some mentioned having better performance with it running from 12 to 14v, and the one time it stopped doing the cutting out thing for me yesterday was when it was being fed around 11v. Then after a power cycle, it did it again.

I'm starting to think this chip or board has some manufacturing defect...

No. Period.


Please post a YT video showing us what you call noise, we have no clue what that word means.

Just to see where the chips fall, I would test once more the chipamp, driving it straight from generator or at most a 1 Op Amp low gain stage, say 3X to 10X tops if beyond what the generator can supply, and from a simple power supply, not boosted batteries or regulated supplies but transformer - diodes - caps. 
Nominal 12VAC will give you some 15-16V DC

The point being to confirm the amp itself fails and not Preamp or supply throw the towel.

Did you scope the +V rail to see if it drops?

That click click click may come from amp protection but also from supply protecting itself.

*In theory* TDA8932 should work fine for that load and supply ..... in practice, who knows?

But if so, stop using it, period.
TPA3118 has a reasonably proven record so far.

Quote from: Tassieviking on July 18, 2025, 11:02:52 AMHow 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.

I got 3 packs of the RPi heatsinks, 1x 14mmx14mmx5mm and 2x 9mmx9mmx4mm per pack, and put 2x of the 14mm under the board right under the IC, and 2x of the 9mm on the chip itself (just to be safe), but nothing seems to have changed.

I'm just grasping at straws here tbh.

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.