skate323k137
Enlightened
Got a Snow Bros PCB in a trade a while back... it plays fine, but the audio has always been quiet. Like, really quiet. Max out the volume pot on my cabs that never go past 40% quiet lol.
Anyway so far I have:
Replaced all 4 electrolytic caps
Replaced the 4558C Op-Amp
Replaced the LA4460N amplifier
Verified the amp is getting proper input voltage
Checked the volume pot - it's labelled 10k but is only really 7k. But it runs smoothly and the (extremely quiet) audio follows it as expected.
I'm really hoping it's not the PX4460 support chip for the amp. Mine is present, but I'm not sure exactly what it's supporting on the amp, or if it would cause this particular problem if it were faulty. Any insight is appreciated.
EDIT
This was fixed by replacing the PX4460, but not actually replacing it. Toaplan left traces and plated holes to use individual caps and resistors for the audio amp instead, so that's what I did. It's documented in the posts below.
Anyway so far I have:
Replaced all 4 electrolytic caps
Replaced the 4558C Op-Amp
Replaced the LA4460N amplifier
Verified the amp is getting proper input voltage
Checked the volume pot - it's labelled 10k but is only really 7k. But it runs smoothly and the (extremely quiet) audio follows it as expected.
I'm really hoping it's not the PX4460 support chip for the amp. Mine is present, but I'm not sure exactly what it's supporting on the amp, or if it would cause this particular problem if it were faulty. Any insight is appreciated.
EDIT
This was fixed by replacing the PX4460, but not actually replacing it. Toaplan left traces and plated holes to use individual caps and resistors for the audio amp instead, so that's what I did. It's documented in the posts below.
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