Something INSIDE THE AMP playing music

Faster7

Member
2006-05-25 2:28 pm
Picked up an amp that I knew had some issues but they should have been minor. (Cosmetic/connection related)

Both channels play, one is just a bit quiet compared to the other side but they can be matched, and when the crossover is in fullpass or high pass, I can hear some component "playing" the input. Sort of a high pitched buzz but can actually make out words (DJ on between songs)

I've wiggled/touched different parts but can't isolate it. It does raise in intensity with the amps bass/treble controls and to some extent with the channel gains. Crossover in low pass I can't hear it but I haven't fed it some bass heavy music and turned it up to duplicate it.

~1996-97ish? Fosgate 200x2

Any suggestions would be appreciated!
 

Faster7

Member
2006-05-25 2:28 pm
That's generally caused by the power transformer. It's generally not a problem. If it is audible once installed, you can try moving the windings on the transformer to see if it eliminates the problem.

That was my first thought before I popped the cover off. Then I found that it only does it with one channels input so was poking around around the low level/preamp parts.

I'll play with it some more and see if that's it. Looks like I need to throw together a dummy load and break out the scope and tone generator to see if everything else holds up...