tubes are dying...

[capoeiraesp]

Hey all,

So I've begun to notice that when I fire up my 5150mk2 (after a min or so on standby) that I get a whistly noise that changes pitch and a bit of crackling and eventually just stops after another minute or so. The current tubes (sovteks and electro hamronix) were put in around 2 years ago and ive mainly played it at bedroom settings in that time, only puttin the vol. above 1 or 2 on a dozen occassions or so. Am I right in thinking it's time to do a retubing?

[Armitage]

A microphonic tube is the usual problem. Try taping each of the tubes (it's probably a preamp tube) with the lead end of a pencil and see if you hear a loud (it's obvious) ring noise. You'll likely just have to replace one tube. If it's a preamp tueb, you can try changing it's location... the one that makes the least difference with noise is the one closest to the power transformer, the furthest from where you plug your guitar in.

[capoeiraesp]

Cheers man, very useful info, I'll go have a crack at soon