(!!!!) (Best Tungsram Single) ECC83=12AX7 Tungsram Hungary NOS 1982 (1.6/1.5mA and Gm=2100/2000) (high Ma and Gm)
(!!!!) (Best Value 1965) 12AX7 Philips Miniwatt Holland like new 1965 (Gm=1900/1700 and 1.5/1.2ma)
(!!!!) (Best Value 1965) 12AX7 Philips Miniwatt Holland like new 1965 (Gm=2000/2000 and 1.6/1.7ma) (Highest mA and Gm)
(!!!!) (Best Value Pair #1) 12AX7=ECC83 Telefunken Germany <> bottom branded GAP/R Computor tube <> bottom smooth plates used/good 1964 era (0.9/0.8ma and 1.0/0.8ma)
(!!!!) (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 Pair 1965 era) 12AX7=ECC83 Philips Miniwatt Holland like new 1964-1965 era (1.3/1.2ma and 1.1/1.2ma)
(!!!!) (Best Value Pair) 12AX7=ECC83 Telefunken Germany <> bottom smooth plates used/good 1960's (0.8/0.8ma and 0.8/1.0ma)
(!!!!) (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 Single) 12AX7 Telefunken Germany <> bottom smooth plates branded GAP/R Computor tube like new 1964 (Gm=1700/2000 and 1.1/1.5ma)
(!!!!) (Best Value Single) 12AX7 Telefunken Germany smooth plates branded DYNACO like new 1964 (Gm=1600/1800 and 0.9/1.4ma)
(!!!!) (Best Value Single) ECC83=12AX7 Tungsram Hungary NOS 1980 (Gm=1500/1800) (0.9/1.2ma)
(!!!!) (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)
(!!!!) (Good Value 1962) M8137=12AX7S Philips SQ France ribbed plates NOS 1962 (0.8/0.9ma and Gm=1350/1350) (Special Quality 12AX7)
(!!!!) (Good Value 1962) M8137=12AX7S Philips SQ France ribbed plates NOS 1962 (1.1/1.1ma and Gm=1550/1450) (Special Quality 12AX7)
(!!!!) (Good Value Single) JRP-12AX7 Raytheon Black Plates NOS 1962 (Gm=1300/1500) (0.7/1.0ma)
(!!!!) (Good Value Single) JRP-12AX7 Raytheon Black Plates NOS 1962 (Gm=1300/1600) (0.7/1.1ma)
(!!!!) (Good Value Single) JRP-12AX7 Raytheon Black Plates NOS 1962 (Gm=1500/1700) (0.9/1.2ma)
(!!!!) (Read Review) 12AX7A=ECC83 Matsushita Japan NOS rebranded Raytheon NOS 1970 era (Gm=1800/1800 and 1.5/1.3ma) (similar to Mullard)
