I have a dBx subwoofer amp. Several years ago it began letting out a "pop" after being on for about 10 minutes. Over the years it has gotten progressively worse, and now lets out a few garbled pops, at 10 minutes. Other than that it works fine (even before and after it pops). My thought was that this could be caused by the filter caps going bad over time. I figure that the 10 minute mark represents a period of thermal expansion. I know from the Bose system in my Corvette that the filter caps on those amps go and can produce similar (and worse) problems.

Yesterday I opened the unit and sure enough, there is some waxy material at the base of the two 10,000 mfd, 80 volt power supply filter caps, one worse than the other. It actually looks more like a sealent to seal the caps to the board, but that wouldn't make any sense. Also the one with more wax around wiggles when rocked even though the solder joints are sound.

Unforetunately, these are not so easy to come by, except of course on ebay where I would need to buy at least 5 for about $35 plus about $15 s/h.

I would sure hate to put in the new caps if this doesn't cure the problem and that being the case, would rather put the $$$ toward a new amp. Before I invest the time and $$$ on this fix, does anyone concur that leaking filter capacitors could be the source of the popping?

On another note, if I do replace the caps, I can get caps of similar size and voltage, but up to 15,000 mfd. The replacement of the two 10,000 mfd caps with 12,000 or 15,000 mfd should help beef up the power supply reserves. Does anyone see a problem with this change???

Thanks guys