(!!!) (Best Single) 12AX7A Sylvania NOS 1970's (Gm=2800/2900)
(!!) (Best Value Single) 12AX7 EI Yugoslavia Smooth Plates TELEFUNKEN copy NOS 1981 (1.0/1.5ma and Gm=1700/2100)
(!!!!) (Best Siemens Single) CV492=ECC83=12AX7 Siemens Halske NOS 1968 (1.1/1.1ma) (Gm=1600/1600) (phono, mic, preamp) 1% section balance
(!!!!!) (Recommended Single) CV4035=M8214=12AX7 Brimar England NOS flying leads 1960's (solder leads into ckt)
(!!!!!) (Recommended Single) CV4035=M8214=12AX7 Mullard England box plates NOS flying leads 1961 (solder leads into ckt)
(!!!) (Best Value) 12AX7A RCA gray ribbed plates "O" getter halo NOS 1965 (1.0/0.8mA and Gm=1600/1400)
(!!!!) (Single) 12AX7 GE tall gray ribbed plates "O" getter halo 1960 era used/good (Gm=1200/1400 and 0.9/1.1ma)
(!!!!) (Best Pair) 12AX7 GE branded 12AX7A International NOS 1977 (1.3/1.3mA and 1.4/1.4ma) (Same Gm) 1-2% matched
(!!!!) (Best Pair) 12AX7 EI Yugoslavia Smooth Plates TELEFUNKEN copy NOS 1981 (1.1/1.1ma and 1.0/1.2ma) 1-5% matched
(!!!) (Single 1958) 12AX7=ECC83 Siemens Germany long plates "o" getter halo 1958 used/good (0.8/0.9ma and Gm=1400/1400)
(!!!) (Best Single 1953) 12AX7 GE gray ribbed plates "D" getter 1953 like new (Gm=1600/1600 and 1.1/1.0ma) (1st version)
(!!!) (Best Value Single) 12AX7=ECC83 SIEMENS HALSKE GERMANY used/good 1966 (0.8/0.9ma)
(!!!) (Recommended Single) 12AX7WA=E83CC SIEMENS HALSKE GERMANY triple mica used/tests like new 1969 (1.2/1.0ma)
