5150 problem - help!

[Guitardavept]

Hey guys,

I recently took delivery of my EL34 1x12 combo, and it’s an awesome thing! However... I’ve noticed that even on relatively low gain settings - 10-11 o’clock on the blue channel - it has a habit of squealing if the guitar is anywhere near it and my hands aren’t muting the strings. Also if I run my finger very lightly down the strings, it sounds kind of on the verge of squealing. This is with the power scaler all the way down, low bedroom volumes.

Another thing is that sometimes the volume seems lower than I remember it being, and the whole thing just doesn’t seem to have the full sound. This is intermittent because I might go back to it a short time later and it seems really loud and full.

I’ve taken my pedalboard completely out of the equation so I can rule that out. I’m guessing it’s a bad tube, but I don’t have any experience with this. What’s the procedure here? Take them all out one by one? Is there an easy way of testing which is the bad one?

Any help or advice or alternate theories on the problem gratefully received!

Thanks!

[evhintexas]

A harmonic tube could cause what you are describing

[Guitardavept]

I’ve got the back off the amp and have done a quick “wooden spoon” test on the tubes, but nothing obviously wrong, and they are all glowing orange as they should. Hmmm ��