Metropoulos Forum

I found some old tubes in my basment that my dad had

RCA 12AX7
Mullard 12 AU7 ECC82

I would think these are old very old.

how should I set up my pre amp tubes

I have

JJ Tesla 12AX7
RCA 12AX7
Mullard 12 AU7 ECC82

I also have the junky marshall ones.

Right now its JJ Tesla, Mullard and then the RCA

Basically I wouldn't use anything other than a 12AX7. They're all interchangeable( you can actually swap 12AX7 for 12AT7 or 12AU7 etc etc without modding the amp). However, the 12AX7 has the highest gain factor out of all of these other tubes. I mean if you're looking to drop the gain some try a lower gain tube in the driver. But if you're like me and need all the gain you can get, run all 12AX7s.

BTW I just installed my Power Brake mod Jim. Works great. Can't wait to try it at the gig this weekend

Jon