Ampeg BA210 distorting

[guitarzen]

I have an Ampeg BA210 that sounds like it has a torn speaker (but the speakers are OK).

I have already disconnected the DSP board with no improvement. I have schematics from elsewhere on this forum.

Does anybody know where I should start looking? The power side or the digital side?

Thanks,

[Jazz P Bass]

schematic link: http://music-electronics-forum.com/t15297/
Did you try to isolate the problem?
Use the CD in, this bypasses the whole preamp. Is it distorted.
Is the headphone or balanced out distorted? These are before the power amp.
If all of these conditions are clean, then you most likely have a power amp problem.