(!!!) (Recommended Single 1962) ECC83=12AX7 Mullard Webcor ribbed plates used/very good 1962 (161 series) in white box (1.0/1.1ma and Gm=1600/1600)
(!!!) (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) 12AX7=ECC83 Mullard UK old logo copper grid posts used/good 1963 (.9/1.0ma and Gm=1500/1500)
(!!!) (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 BRIMAR England BVA ribbed plates used/good 1960's (0.8/1.0ma and Gm=1400/1500)
(!!!) 12AX7 BRIMAR England BVA ribbed plates used/good 1960's (0.9/1.1ma and Gm=1350/1500)
(!!!) 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)
(!!!) 7025 RCA ribbed gray plates low hours/tests like new 1960's faded printing (Gm=1500/1800 and 0.9/1.3mA) (V1 guitar amp)
(!!!) 7025 RCA ribbed gray plates used/good 1960's (Gm=1350/1450 and 0.7/0.8mA)
(!!!) 7025 RCA ribbed gray plates used/good 1960's (Gm=1350/1600 and 0.6./1.1mA) (V1 guitar amp)
(!!!) 7025 RCA ribbed gray plates used/good 1970 era faded printing (Gm=1500/1500 and 0.9/1.0mA) (V1 guitar amp)
(!!!) 7025 RCA ribbed gray plates used/good 1972 (Gm=1450/1400 and 0.9/0.8mA) (V1 guitar amp)
(!!!) 7025 RCA ribbed gray plates used/tests like new 1960's faded printing (Gm=1500/1500 and 1.1/0.9mA) (V1 guitar amp)
(!!) (Best Single 1966) ECC83=12AX7 Siemens Halske Germany NOS 1966 (162 Series) (Gm=1500/1600 and 1.0/1.1ma)
(!!) (Best Value Holland 1959) 12AX7 ADZAM Holland NOS 1959 large "O" getter halo (.8/1.1ma and Gm=1400/1600)
(!!) (Best Value Single) 12AX7 EI Yugoslavia Smooth Plate TELEFUNKEN copy NOS 1979 (1.0/1.2ma and Gm=1800/1900)
(!!) (Best Value Single) 12AX7 EI Yugoslavia Smooth Plate TELEFUNKEN copy NOS 1979 (1.9/1.2ma and Gm=2400/1800)
(!!) (Best Value Single) 12AX7=ECC83 Mullard UK copper grid posts used/good 1965 (Gm=1400/1400)