West Hartford, CT
|reply to amungus |
Re: random hiss from speaker - capacitor?
1. What caused the cap to scorch? Might be a symptom of a larger issue.
2. Is there a cell phone anywhere the speaker [or the amp or the wiring] when it randomly hisses?
Thinking it was the proximity of the two resistors - they were both touching, so I gently gave some 'breathing room' there.
There is a 3G tablet (and sometimes cell phone) nearby most times, but the amp is in the sub, which is on the floor - about 2-3' of distance b/w devices and the amp. Unlikely to interfere, but not a bad thought, and certainly a possibility. We could try having those moved slightly.
Ceramic caps usually don't go 'intermittent'... Just for grins, I'd take a closer look at those power resistor's leads for 'cold' solder connections on the board, and 're-wet' them with fresh solder if needed...
If You're Unsure, "RTFM"... If You're SURE, "RTFM" Anyway.
That's what I thought too. That those little ceramic guys were pretty solid. Worth asking though, since that's the only visibly bad area of the board.
Might check for cold solder, wouldn't surprise me at all...
As for channels - yes, since the sub contains the amp circuitry, it seems to send a little hiss to L/R channels.