Microphonic tube in Fender amp

[Low_fidelity2100]

I Had heard of this happening. But had never actully had it happen to me before. Until last nite. One of my preamp tubes is causeing the squeeling. I found which one by careful tapping and pokeing of the tubes. But I guess my question is.
Is this a problem with the tube itself? Or the tube socket or sumthing? I mean do I just need to push the tube back into the socket firmly? or do I need to replace it?
The squeeling only seems to happen at high volumes. But this is still quite annoying.
Any answers from anyone would be greatly appreciated.
Thanx
ed

 

[Curly]

Re: Microphonic tube in Fender amp

depending on the circuit, you can sometimes "bury" that tube in another position, like V5 ...
see this tube layout for reference:
tube layout

if that doesn't work, you might just have to get another tube

 

[Stratcat]

Re: Microphonic tube in Fender amp

I would replace the tube first.

 

[Low_fidelity2100]

Re: Microphonic tube in Fender amp

depending on the circuit, you can sometimes "bury" that tube in another position, like V5 ...
see this tube layout for reference:
tube layout

if that doesn't work, you might just have to get another tube

Thanks for the suggestions. Although I really don't know to much about amps, So that artical didn't make much sense to me. And my amp doesn't have a tremolo so I dunno what the V5 possition would be then. I'm probably misunderstanding it though.
From what I can tell from that artical though. The tube thats causeing the microphonics would be the V1 tube? Its the first tube on the right hand side when looking at it from the back. I know its a 7025 preamp tube (not 12ax7, cause I purposely got the 7025s cause they're lower gain). So would that make any difference?
I'm confused still. haha. Ed

 

[Curly]

Re: Microphonic tube in Fender amp

yes, V1 is on the right

V1 is the most critical tube for the first channel

you can try switching it with another 12ax7 and see if that works, or just do what Stratcat said, and replace it

7025 isn't lower gain, it's just a military designation for a mil spec 12ax7 ... nowadays, the two names are used for the same tube (like on Sovteks)