The last few days of playing, after about 10-15 minutes of playing, the volume on my MESA Express 5:25 cuts down to practically nothing. It won't go back to normal until I leave it off for a few hours, but then it will do the exact same thing after 10-15 minutes of playing. Is this a sign that it's in need of new tubes? If so, can I get a recommendation for some new tubes? It has 2 EL-84's for power tubes, and 5 12AX7's for pre-amp.
That's the first, simplest place I'd try correcting the problem. PM me. I have a few sets of EL-84s from my old 5:25 that I have no foreseeable use for. I'll send them to you for nothing.