MTX Thunder 4244

[mike49504]

With the amp powerd up and no rca's plugged in the front left channel sounds like a am radio ..

Eerything appears to test good

Any Ideas?

[Perry Babin]

It sounds like it's oscillating. Do you see a thin line/trace on the speaker terminals or is it a wide, fuzzy trace?

[mike49504]

What settings should i set my scope to ??

I tryed differnt settings but it just stayed a thin line and didnt appear to move at all

[Perry Babin]

Will it produce audio?

[mike49504]

Yes it produces clean audio out of all 4 channels..

I went thru the settings again on my scope and with no rca's plugged in i can get a fuzzy line to appear

[Perry Babin]

If the trace is sharp at 5v/div, the problem is likely in the preamp section.

Does it do it regardless of the crossover/gain... settings?

Have any of the op-amps been replaced previously?

Is the bias properly set?