(!!!!) (Single) 12AY7 GE branded Raytheon black box plates "D" getter 1953 era in white box (3.3/3.1ma) (Same Gm)1 low noise tube) 12AY7 GE branded Raytheon black box plates "D" getter 1953 era in white box 1 section) 3. 3ma Gm=1700 1 section) 3. 1ma Gm=1700 Tested on Amplitrex Good used mA = 1. 8 2. 3mA Good used Gm = 1200 1400 Recommended for Leak Stereo 20 1962 Fender Bassman 1954 Clark Amplification Anthony Wilson Model 112 Combo (sub for 12AX7) Decware ZBox Fender 5E8 A Apex 460