(!!!!!) (Recommended Single) 12AX7 BRIMAR BVA England NOS narrow ribbed plates NOS 1960 (1.4/1.5ma) (Highest mA and Gm)
(!!!!) (Best Value Single) 12AX7 Telefunken Germany smooth plates branded DYNACO like new 1964 (Gm=1600/1800 and 0.9/1.4ma)
(!!!!) (Best Value Single) 12AX7 Hitachi Japan branded ITT NOS 1963 (1.0/1.7ma and Gm=1500/1950)
(!!!!) (Best Value Single) 12AX7 Raytheon Black Plates NOS 1962 (.9/1.1ma and Gm=1400/1600)
(!!!!) (Best Value used) ECC83=12AX7 Fisher Mullard ribbed plates used/good 1964 (.8/1.2mA Gm=1400/1600)
(!!!!) (Best Value used) ECC83=12AX7 Fisher Mullard ribbed plates used/good 1964 copper grid posts (.7/.8mA Gm=1400/1500)
(!!!!) (Best Value Pair 1965 era) 12AX7=ECC83 Philips Miniwatt Holland like new 1964-1965 era (1.3/1.2ma and 1.1/1.2ma)
(!!!!) (Slightly microphonic single) 12AX7=ECC83 Mullard UK branded Philips ribbed plates NOS 1962 (161 Series) (1.0/1.2ma and Gm=1600/1650)
(!!!!) (Best Siemens Single) ECC83=12AX7 Siemens Halske Germany branded SONOTONE NOS 1962 (Gm=1900/1700) (1.5/1.3ma)
(!!!!) (Best Value Pair #2) 12AX7=ECC83 Telefunken Germany <> bottom branded GAP/R Computor tube <> bottom smooth plates used/good 1964 era (0.8/0.8ma and 0.8/0.8ma)
(!!!) (Best Value Single) 12AX7=ECC83 FISHER HOLLAND large "O" getter halo 1960 used/good (Gm=1550/1600 and .9/1.0ma)
(!!!) (Best Value Single) 12AX7=ECC83 FISHER HOLLAND large "O" getter halo 1961 used/good (Gm=1500/1600 and .9/.9ma)
(!!!) (Good Value) 12AX7 RCA "long gray plates" with "D" getter used/good 1960 good printing (0.6/0.7mA and Gm=1400/1500)
(!!!) (Recommended Single) 12AX7 RCA "tall gray plates" and "D" getter halo branded Raytheon used/good 1950's (Gm=1900/2100) (1.3/1.7ma)
(!!!) (Recommended Single) 12AX7A Sylvania NOS 1970's (Gm=2500/2800 and 2.2/2.7ma)
(!!!) (Recommended Single) JRP-12AX7 Raytheon Black Plates NOS 1962 (Gm=1450/1600) (1.0/1.3ma)
(!!!) 12AX7 Sylvania 1960-1965 used/tests like new small mica flake inside tube (Gm=2400/2800)
(!!!) (Best Single 1954) JG-12AX7 GE gray ribbed plates "U" getter 1954 used/tests like new (Gm=1500/1600 and 1.1/1.1ma)
(!!!) (Good Value Single) 12AX7=ECC83 Mullard GE UK ribbed plates used/good 1966 (.8/.9ma and Gm=1450/1600)
(!!) (Best Value Single) ECC83=12AX7 Tungsram Hungary 1980 era branded Amperex NOS 1985 (1.3/1.6ma and Gm=1800/1800)
