Amp sounds pretty good, put in a couple of JJ 6V6, biased by tech plus a couple of 12AX7 pre-amp tubes from 1968 that I have. More musical without the Chinese tubes, clean all the way up but a soft amp compared to a Blues Jr or Pro Jr. Recently power shuts-off by itself at times, no apparent reason - for about 1/2 second then comes back on. Happens maybe once or twice in a 2 hour session, sometimes goes a couple of days no problem. I just hate intermittent problems. Can't use it on a gig and hard to locate. Not a bad house circuit or breaker, not the power cord, not a loose fuse-holder. Inside of the amp is clean, nothing appears to be dis-colored. I notice the PT has a sticker that says "Thermal Fuse" - am I on the right track here ? Am pretty sure it's a transformer problem.