Mesa Boogie Electra Dyne clean channel problem

[My Pet Monster]

I've had my Electra Dyne for a couple of years or so now and really love its range of tones.
However, the clean channel all of a sudden has developed a problem, experiencing a significant reduction in volume. With the master volume cranked to halfway, its only conversation-level loud. Messing with clean/vintage volume balance on the back doesn't resolve the issue.
Before I take it to an amp repair guy, has anyone else experienced this issue? Could it be something a simple as a faulty tube dedicated to the clean channel? Or something to do with the clean/vintage volume balancing circuitry?
Thanks in advance for your help.

 

[elvis]

Yes, I'd go with a tube change. I had a couple of tubes go bad when I got my Dyne, the PI (during the first song of the first practice I used the amp at) and the clean mode tube, which did what you're describing.

 

[My Pet Monster]

Thanks mate. I've ordered a couple of 12ax7s to see if that remedies the issue.

Cheers.

 

[YellowJacket]

First guess with a tube amp is almost always tubes. Check the preamp tubes and look at the tube task chart in the user manual. You'll want to check the two preamp tubes that are in the signal chain for the clean mode.

http://www.mesaboogie.com/manuals/electraDyne_091007.pdf

 

[My Pet Monster]

A change of preamp valves resolved the problem. Cheers, chaps.