Channel 3 Not Working

[OlBoyMikeRyan]

Channel 1 and 2 are totally fine. Channel 3 sounds like I'm getting 1% volume. I can very barely hear it working and if i crank the amp to ungodly volumes I can hear it. But obviously that's not ideal.

Any ideas on what gives? This is a 90w combo. I have zero electrician skills and am not trying to die so I'd prefer not to go poking around back there unless I absolutely have to.

I've also always had issues with the footswitch with this amp, but the issue persists even when I'm using the dial in the back to change channels.

 

[domct203]

First thing to check is preamp tubes.

Per your owners manual there is a tube task chart on page 62 listing the preamp tube locations and their function.

There are 3 tubes that are unique to ch 3, V4, V5 & V6. Start with those positions, swapping in a known good 12AX7 one at a time until you find the bad one.

Dom