I picked up cheap a Peavey T-Max amp last week and I love it overall! I have been busy, however still made time to try/test it out a couple times. Everything is good. Never owning any amp before that had tubes I posted a thread about the pre-amp 12AX7 that's in it and about replacing it if I should. I received a lot of great responses and a fellow Talk Bass member very kindly actually sent me a Mesa/Boogie 12AX7 to try out. I have been unusually busy since last weekend, but finally tonight I sat down and opened the amp. The 12AX7 that was in it sound alright to me (again having no real tube knowledge) but I wanted to try out the Mesa tube so I open the amps case, wiggled the tube loose and then put the Mesa tube in. I plugged the amp back into the outlet and powered it on. I let it warm up about five minutes then started playing. I did notice the Mesa tube when using the tube channel did offer a little more gain and distortion which I like and also I swear it was even a little louder and clearer, however that could just be myself telling me that because I know this is just simply one 12AX7 tube and in the pre-amp at that. But I liked what I heard so I left it in there. I am now curious about the old tube. Could it be the original that came in the amp from Peavey's factory? I included a photo below, it's a crappy cell photo but on it in goldish text it is marked "SVETLANA ELECTRON DEVICES 12AX7 MADE IN RUSSIA." The tube still works so I don't want to discard it, however it could be old too. I heard pre-amp tubes last long but if this is the original it's over 15 or more years old. Any insight on this tube? I have heard some praise for the true Russian made tubes, but not sure about this one.