Socket/microphonics question

[coyoteblue]

I've got a 70's Deluxe Reverb and was having a problem with there being too much "presence" coming through the speaker. The bass sounded flabby, but not dull. I checked the tubes and found both V2 and the V4 was microphonic. I exchanged the V2, but when I moved the V4 tube around a bit, the microphonic qualities stopped, and the amp sounded fine again. Is this just a dirty socket or do I need a new socket? In a related issue, I had a power tube socket malfuction and smoke my resistors last week. This was repaired. Could the two issues be related? When I blew the screen resistors on the power tubes, could this have affected other socket connections? Or just a coincidence that I'm having socket problems? Could there be an issue in the circuit board that is making my preamp tubes go microphonic? Both tubes were new, one only a few days old.

[rockon1]

Yes,it sounds like just a dirty/loose socket and probably not related to your power tube socket problem aside from the fact they are both old sockets. You may want to retention the offending socket then use some contact cleaner on the tube and work it in and out of the socket a few times. Careful though there may be LETHAL voltages present and the caps should be drained prior to retentioning the socket! Its always a good iea to clean the tube sockets now and again. Also brand new tubes can be microphonic. Bob

[coyoteblue]

I'll clean the tubes and socket tonight and see if this alone works. I'm wondering if there is anything in the circuit board that causes tubes to become microphonic. I've had some problems with tubes going microphonic lately.