Rich at Mesa Boogie was kind enough to send me a new set of EL84s and one 12AX7 to put in the V1 slot.
So far so good, I've used it for two weeks now and it hasn't cut out on me yet (touch wood). This would be my
third set of EL84s, so it MIGHT have been the 12AX7 in the V1 slot, I'm not sure...