OK, so far so good. I just need another day or so to finish my listening, if that's ok? I am in the middle of moving at the same time, so time has been split many different ways...Oh yeah, I am supposed to work too, eh
How did you determine that the 12AU7 (very similar to 5963) is a plausible substitute for 12AX7 (5751/7025)? Aren't they a bit remote? (this is really a newbie question). I notice that none of the roll gang particularly liked the 12au7 and one reported some odd behavior.
Is this all safe because the MGH is self-biasing? Would any 12A*7 tube be OK? Is there any danger of frying the tube and/or amp with more remote substitutes?