Quote Originally Posted by spendorman View Post
From what I read a while back, early JJ EL34's were not terribly reliable, they soon improved the situation. I have used JJ KT77's and EL34's in several amps, not had a failure, yet!
I had so many problems with JJ valves over several years that I always recommend customers to give them a wide berth. I used to do a lot of work on guitar amps, which were usually valved, and I saw loads of early, random failures... I have heard rumours that quality has improved markedly over the last couple of years but I can't really comment from personal experience as I no longer supply valves and only do the odd guitar amp these days.