Tube amp bias adjustment advice

but I asked my GF and she said it sounds balanced when seated in the middle.

Yikes! Do you notice any hearing loss in other situations?

@mmporsche The first step is to swap the interconnect cables left for right at the inputs to the amplifiers so that you can determine if the amps are at fault. It could be something upstream.

If the problem stays put => amplifier problem
If the problem moves => problem upstream
If the problem stays put, swap the input tubes, not the power tubes. In this way no bias readjustment is needed. Most of the gain in the amp occurs in the input tubes so this is the most likely area to have a gain issue!

The bias will not affect the gain unless its a mile off! It affects *distortion* and usually at higher power levels.


Keep us informed of your progress.