Help!! My Mk IV's Lead channel is making unpleasant sounds!!

[electrik]

The lead channel squeels like hell, and also makes loud rumbling farty sounds into the speaker. What's wrong? Microphonic preamp tube maybe? If so, which one?

Help please I have a gig on Sunday. :x [/img]

 

[Shep]

sound's like pre amp tube...V3 or V4.. just change them...

Tom

 

[metalmaster]

Unfortunately the only real way of finding out is by switching a new tube into each socket one at a time until the noise goes away. 3 and 4 are good ones to try first though. Hope this helps.

 

[electrik]

Well I've tried swapping the V3 and V4 tubes with the spare tube that comes with the amp, and I've also tried switching them around, still no avail.

 

[Shep]

if it's just the lead channel...it sounds like a tube..try the other's..if not then it's pre amp problem..

 

[Russ]

I would agree. Just play musical tubes with the preamp tubes until you find an acceptable mix. If you cannot find the culprit or do not have the time, go out and buy yourself a fresh set of preamp tubes.