My Fryette LX II is running in stereo, and one of the two outputs is noticeably louder than the other. This wasn’t happening before. To test it, I swapped the speaker cables and also swapped the speakers themselves, and the volume difference always stays on the same output channel of the LX II. What could cause one stereo channel to get louder, and what’s the recommended way to diagnose or fix it?
Hello again Leo,
You did some great debugging.
Are the trim pots for presence and depth approx. the same, what about the impedance selector for each channel? How different are the channels? This could indicate the phase inverters (V1 and V2) are driving the power tubes at different levels, or it could be the power tube pairs are not outputting the same amount of power.
I’d start by swapping over the phase inverters, then check. Then move on to swapping over the power tubes as pairs i.e. (V3, V4) move to (V5, V6) etc. This should move the issue to the other channel if one of these reasons is the cause. Then it would be a case of retubing.