Volume problem

[rstewart2000]

I am having a problem with my Mark V head and was wondering if any one has had the same problem, or would know if maybe it is a simple issue with the tubes. With the master volume turned up, the amp will go from a normal loudness to very quite, then after a few minutes back to loud, then back to quiet intermittently. Mesa support is closed for the holidays, so I was hoping someone may be able to help. Thanks

 

[eudaimonia02912]

That is a classic sign of dying power tubes. It could be something else, but that's the most likely culprit.

Make sure that your footswitch cable is plugged in properly, too.

 

[screamingdaisy]

It could also be a preamp tube.