Dear Abby,

I think my wife is cheating on me. I am a travelling musician and note strange things when I come home. Her mobile rings and she steps outside or says, "Call me 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 home.

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 show up at their gigs.

He wanted to borrow my amp. That's when I got the idea to find out for myself. I said: "Sure you can use my amp but I want to hide behind it and see if she comes into the club and who with." He agreed.

Saturday night came. 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, when I noticed one of the power tubes was not glowing like the other three.

Is this something I can fix myself or do I need to take it to a technician?

Thanks.
Very Concerned.