Help me mix my Preamp tubes for my roadster

[ElectricTurkey4369]

I just bought a roadster today, sounds awesome but I'm not crazy on Mesa tubes. The power section is running el34 and Preamp all Mesa 12ax7s. Now I also have some spare EH Preamp tubes that I want to run, but I need help on which positions I should run them in. Also, on the Mesa Preamp tubes they have "Russian 2" on them, but one doesn't. Is it Chinese or something? Thanks guys.

 

[domct203]

The Russian-2 is an EH. If the other one just says "Russian", it's a JJ. If it just says Mesa 12AX7 it may be a Chinese tube. Post a pic of it if your not sure.

Keep the EH tubes out of the cathode follower spots, V3 & V5. The JJ or Chinese are fine there. Keep the JJ out of V1, it will darken the amp and neuter it's high end response. In V1 I would try the EH or Chinese. The rest are mix and match to taste.

Dom