Power tube not heating up??

Hi everyone,

I've recently purchased a used Mesa F-50 combo which sounds fantastic. I wasn't sure how old the Mesa brand power tubes were (and was tone curious), so I tried a pair of JJ 6L6 and a pair of Svetlana 6L6's that I had. Only slight tone differences really, but I encountered a problem new to me.
One of the power tube sockets seems to have an issue, The filament in the tube in that socket won't heat up occasionally. I have to pull it, re-insert it, and sometimes even swap the tubes around to get them both to light up.
I have tried it enough to learn it is not a particular tube, just that particular socket.

Any ideas? I have cleaned the sockets with contact cleaner.

Thanks in advance!

Tuckerbomb

You can try to tighten up the tube pin contacts in the socket. VERY GENTLY squeeze them together to make better contact with the tube pins.

Just make sure the amp is unplugged and don't use anything metal unless you discharge the power filter caps first. Gently push the contacts closed, but don't close them too much or it will be tough to put in tubes. I use a plastic trimmer screwdriver to gently push them a little closer to each other.


Good luck.

That did the trick. Thanks! The F-50 is now up for trade in the classifieds though. Not quite the right gain structure for me!