(!!!) (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)
(!) 12AX7A FANON by HITACHI JAPAN used (0.9/0.9ma
(!) (Best Value) 7025A=12AX7A China branded International Yugo NOS 1990's (1.0/0.9ma and Gm=1700/1600)
(!) (Best Value) 12AX7A China tests like new 1990's (1.1/1.2mA and Gm=1800/1900)
(!!) (Good Value) 12AX7A/7025 Sylvania used/good 1970's (Gm=2300/1900)
(!!!) (Good Value Single) 12AX7A RCA ribbed plates used/good 1960's faded printing (Gm=1400/1700 and 0.8/1.1ma)
(!!!!) (Best Value 1965) 12AX7 Philips Miniwatt Holland like new 1965 (Gm=2000/2000 and 1.6/1.7ma) (Highest mA and Gm)
(!!!!) (Best Holland Single) 12AX7A=ECC83 Amperex Globe Logo Holland ribbed plates NOS 1970 (1.4/1.4ma and Gm=1700/1800) 1-2% section balance
(!!!) (Best Value Single) 12AX7=ECC83 Mullard UK ribbed plates used/good 1967 (1.7/0.8ma and Gm=2000/1600) (V1 guitar amp)
(!!!) (Good Single) 12AX7 Amperex Bugle Boy Holland "Long Plates" with "D" getter used/very good 1958 (Gm=1500/1600 and 1.1/1.1ma)
(!) (Best Toshiba Single) 12AX7 Toshiba Lindal Japan NOS 1960's (Gm=1800/1800)
(!!) (Best Value Single) 12AX7=ECC83 Mullard UK copper grid posts used/good 1965 (Gm=1400/1400)
(!!) (Good Value Single) 12AX7A GE NOS 1976 (0.9/1.3mA and Gm=1400/1800)
(!!) (Single) JAN-12AX7WA Sylvania NOS 1974 (Gm=1800/2500 and 1.5/2.1ma)
(!!!) (Best Single 1965) JHS-12AX7WA Sylvania NOS 1965 (1.3/1.5ma and Gm=1700/1800)
(!!!!) (Best Single) 12AX7 GE NOS tall ribbed plates 1964 (1.3/1.2ma Gm=1700/1700) 1-2% section balance
(!!!) (Recommended Pair) 12AX7 Triotron by Philips Holland NOS and Valvo Holland like new 1966-1968 (1.7/1.5ma and 1.5/1.5ma)
