18Watt.com

Hey folks,

I get some very faint and soft hissing and rubbing sounds from my new TMB (sIII variety) at startup....Then, after a few more minutes, the amp is perfectly quiet and no problems whatsoever...

This is not that big a deal to me, since the amp basically evens out to normal if I wait a little longer...But I'm still curious to hear some confirmation...

This largely sounds like a tube issue...since it goes away once the amp warms up.

Maybe I'm flipping the standby switch too quickly...I dunno...

thoughts?

-Frank

You could try swapping out the tubes just to prove or disprove your theory.

Even swapping V1 and V2 would finger V1 or not (the most likely culprit).

--mark h

I had a simular problem and it turned out to be a el84 going south it would hiss a little and get some scratchy sounds then it would stabilize. I would check out the tubes.
Rob

ditto the skanky tubage diagnosis

Sounds like my problem, which means my expensive Polams are "going south" after only a few hours of use.

I've had this before. One time it was an EL84 and the other it was V1.