Dear Abby…

I think my wife is cheating on me. I am a working musician and, as
you would expect, travel a lot. I have been noticing strange things
happening when I get home. Her mobile phone rings and she steps
outside to answer it or she says, “I'll call you back later”. When I ask
her who called she gets evasive.

Sometimes she goes out with friends but comes home late, getting
dropped off around the corner and walking the rest of the way. I once
picked up the extension while she was on the phone and she got very angry.

A buddy of mine plays guitar in a band. He told me that my wife and
some guy have been to his gigs. He wanted to borrow my guitar amp.
That's when I got the idea to find out for myself what was really
happening. I said “sure, you can use my amp but I want to hide behind it at the gig and see if she comes into the venue and who she comes in with”. He agreed.

Saturday night came and I slipped behind my Marshall JCM800 half
stack to get a good view. I could feel the heat coming off the back of the
amp. It was at that moment, crouching down behind the amp, that I noticed that one of the tubes was not glowing as bright as the others.
Is this something I can fix myself or do need to take it to a technician?

Thanks,
Very Concerned