In my mpulse 360, I decided to try out a few tubes out. Originals were 12ax7-a Mesa Tried sovtek 12ax7lps. As many said, this is a high gain that really easely distorts, but a very nice distortion is produced. Overall volume dropped though. Tried 12ax7EH. Very clean, very nice. Much cleaner tone than with the originals. But again, significant overall volume drop. Anyone else has experience playing around with the simul-state series of Mesa amps.