Bob's a nice guy but I can't buy into his belief that the best tube for everything is a JJ. On the other hand, Doug also recommends the same tube configuration for everything too so...
I had JJ's (they came stock) in a JSX and one day one or two of the power tubes made odd loud sounds, went blue for a second and then back to normal. I turned the amp off immediately. It never happened again. They were brand new too. It happened one other time with tubes I got from Bob.
I stick to Mesa tubes now. I always felt they sounded best in my Mark IV. I'm going to try some GTs in my RKII soon.
