Thanks for this response -- I plugged a patch cable between the preamp output and power amp input jacks. Unfortunately it didn't result in any changes to the behavior/volume. This amp is currently at a practice space so I think at a minimum I need to take it home, open it up, and put it through a good cleaning and at least a visual inspection of the board.
Now I need to find another preamp and poweramp to move on to your next suggestion to try and narrow down where the volume loss might be happening. Also considering building an audio probe after seeing a couple youtube videos about using them to troubleshoot amps. This is my first amp repair after doing a lot of small scale electronics work (pedals, etc.).
Also, thanks for the schematic -- it's much clearer (particularly the power amp section) than the one I'd found elsewhere.
You seem to be familiar with this model -- any other typical issues that might be good to hone in on?
Thanks again!
Now I need to find another preamp and poweramp to move on to your next suggestion to try and narrow down where the volume loss might be happening. Also considering building an audio probe after seeing a couple youtube videos about using them to troubleshoot amps. This is my first amp repair after doing a lot of small scale electronics work (pedals, etc.).
Also, thanks for the schematic -- it's much clearer (particularly the power amp section) than the one I'd found elsewhere.
You seem to be familiar with this model -- any other typical issues that might be good to hone in on?
Thanks again!