Match Pair MESA BOOGIE STR 12AX7A Preamp Tubes TV7&Maxi Test NOS NIB High Gain ¥
Gain: (109.7 & 107.9 and 105.0 & 109.3 )MU and side balance. Mutual Conductance (GM)Test: 50 & 50 and 53 & 60 (49 = NOS AVERAGE & 32=Good MINIMUM). Test results will vary between testers as it is not an exact science.