(!!) (Best Value Single) ECC83=12AX7 Tungsram Hungary 1980 era branded Amperex NOS 1985 (1.3/1.6ma and Gm=1800/1800)
(!!!!) (Best Tungsram Single) ECC83=12AX7 Tungsram Hungary NOS 1982 (1.6/1.5mA and Gm=2100/2000) (high Ma and Gm)
(!!) (Best Value Holland 1959) 12AX7 ADZAM Holland NOS 1959 large "O" getter halo (.8/1.1ma and Gm=1400/1600)
(!!!!) (2nd Best Pair) CV4004=12AX7 Mullard NOS 1981 (0.9/0.9ma and 0.9/1.0ma)
(!!!) (Best Value Single) 12AX7 Fisher Telefunken ribbed plate used/good 1960 era fair printing (Gm=1400/1600 and 0.9/1.1ma)
(!!) (Good Value) 12AX7 Siemens Halske Germany rebranded "BOGEN" used/good 1960 (161 Series) (Gm=1400/1500 and 0.8/0.9ma)
(!!!!) (Recommended Single) 12AX7 RCA black plates branded GE "U" getter NOS 1956 (1.1/0.9ma and Gm=1600/1400)
(!!) 12AX7A Westinghouse pinched plates "D" getter used/good 1960 era no printing (Gm=1450/1650)
(!!!!) (Recommended Pair) 12AX7 Philips and Valvo Holland NOS 1965-1966 era (1.2/1.1ma and 1.3/1.2ma)
(!!!!) (Best Single 1961) 12AX7=ECC83 Philips Miniwatt Holland 1961 large "O" getter halo NOS (1.8/1.3ma and Gm=2100/1700)
(!!!) (BEST SINGLE 1964) AFLC-12AX7WA Sylvania NOS 1964 (Gm=1900/1900)
(!!) (SINGLE) 7025 RCA gray NOS 1970 era (Gm=1450/1600 and 1.0/1.2mA)
(!!!) (Best Value Single) 12AX7=ECC83 SIEMENS HALSKE GERMANY like new 1966 (1.0/1.1ma)
(!!!) (Best Sylvania 1955) 12AX7 Sylvania pinched black plates "square" getter halo NOS 1955 (Gm=1500/1700, 1.0/1.1ma)
(!!!) (Best Single 1962) JHS-12AX7 Sylvania NOS 1962 (Gm=2600/2500 and 1.8/1.9ma)
(!) (slightly microphonic single) CV4004=12AX7 Mullard NOS 1981 (1.3/2.1ma)
(!!!) (Recommended Single) 12AX7=ECC83 Mullard UK old logo copper grid posts used/good 1963 (.9/1.0ma and Gm=1500/1500)
(!) (Best Value) 7025A=12AX7A China branded International Yugo NOS 1990's (1.0/0.9ma and Gm=1700/1600)
(!) (Best Value) 12AX7A China used/good 1990's no printing (0.9/1.1mA and Gm=1600/1700)
(!!) (Good Value) 12AX7A/7025 Sylvania used/good 1970's (Gm=2300/1900)
