I just bought a 50 cal + head online. After using the lead channel, set for high gain, for about 10 minutes, the gain pretty much shuts down and it goes to a moderate/light overdrive. Plus, both channels are noisy. From searching through this forum, i thought that it was a preamp tube problem, so i put in some new mesa 12ax7s in v1,v2 and v3. It didn't fix the problem. The gain was great while it lasted.
Any ideas?
Any ideas?