(!!!!!) (Best Mullard Pair) 12AX7=ECC83 Mullard UK ribbed plates NOS 1970-1974 (1.2/1.3ma and 1.2/1.1ma) (same Gm)
(!!!!) (Best Pair) 12AX7 EI Yugoslavia Smooth Plates TELEFUNKEN copy NOS 1981 (1.1/1.1ma and 1.0/1.2ma) 1-5% matched
(!!!!) (Best Pair) 12AX7 GE branded 12AX7A International NOS 1977 (1.3/1.3mA and 1.4/1.4ma) (Same Gm) 1-2% matched
(!!!!) (Best Single 1958) 12AX7 GE tall gray ribbed plates "U" getter 1958 like new (Gm=1800/1800 and 1.3/1.3ma) 1% section balance
(!!!!) (Best Value Pair #1) 12AX7A RCA gray ribbed plates NOS 1967-1973 (best tone) (0.9/0.9ma and 0.9/1.1ma) (Fender)
(!!!!) (Single) 12AX7 GE tall gray ribbed plates "O" getter halo 1960 era used/good (Gm=1200/1400 and 0.9/1.1ma)
(!!!) (Best Single) 12AX7A Sylvania NOS 1970's (Gm=2800/2900)
(!!!) (Best Value) 12AX7A RCA gray ribbed plates "O" getter halo NOS 1965 (1.0/0.8mA and Gm=1600/1400)
(!!!) (Good Value Single) 12AX7=ECC83 Mullard GE UK ribbed plates used/good 1966 (.8/.9ma and Gm=1450/1600)
(!!!) (Good Value Single) 12AX7A RCA Magnavox ribbed plates used/good 1961 (Gm=1500/1900 and 0.8/1.3ma)
(!!!) (Good Value Single) 12AX7A RCA ribbed plates NOS 1974 (Gm=1600/1400, 1.1/0.8ma)
(!!!) (Good Value Single) 12AX7A RCA ribbed plates used/good 1960's faded printing (Gm=1400/1700 and 0.8/1.1ma)
(!!!) (Good Value) 12AX7A RCA gray ribbed plates "O" getter halo NOS 1973 (1.0/0.9mA and Gm=1400/1550)
(!!!) (Good Value) 12AX7A/7025 GE NOS pinched plates 1976 (0.9/1.7ma and Gm=1500/2000)
(!!!) (Recommended Single) 12AX7A RCA gray ribbed plates NOS 1971 (Gm=1600/1800 and 1.2/1.4ma)
(!!!) (Recommended Single) 12AX7A Sylvania NOS 1970's (Gm=2500/2800 and 2.2/2.7ma)
(!!!) (Recommended Single) 12AX7A Sylvania NOS 1970's (Gm=2600/3000)
(!!!) 12AX7 Sylvania 1960-1965 used/tests like new small mica flake inside tube (Gm=2400/2800)
(!!!) 12AX7=ECC83 Mullard UK "long plates" with "D" getter used/50-60% (0.6/0.7ma Gm=900/1000 - low Gm) (mC1 series)
(!!) (Best Value Single) 12AX7 EI Yugoslavia Smooth Plates TELEFUNKEN copy NOS 1981 (1.0/1.5ma and Gm=1700/2100)