(!!!!) (Best Quad) 8417 RCA by Sylvania NOS 1960's - 1970's (100, 101.6, 103, 102ma)
(!!!!) (Best Quad) 8417 RCA by Sylvania NOS 1970's (95.5, 96, 98, 99.6ma)
(!!!!) (Best Value used) ECC83=12AX7 Fisher Mullard ribbed plates used/good 1964 copper grid posts (.7/.8mA Gm=1400/1500)
(!!!!) (Recommended Pair) 8417 Sylvania branded RCA NOS 1972-1973 (119.2ma and 123.7ma)
(!!!!) (Recommended Quad) 6HA5=6HM5=EC900 Amperex Holland "Globe Logo" NOS in white boxes 1971 (9.8/9.8/10.0/10.2ma)
(!!!) (Best Pair) 6HA5=6HM5=EC900 Amperex Holland "Globe Logo" NOS in white boxes 1971-1972 (12.0ma and 12.8ma)
(!!!) (Best Single) 8417 Sylvania NOS (121ma)
(!!!) (Best Single) 8417 Sylvania NOS 1970 era (111ma)
(!!!) (Best Single) EC92=6AB4 Siemens Halske Germany branded Mullard NOS 1964 (10ma)
(!!!) (Best Sylvania Single) 8417 Sylvania NOS branded Westinghouse NOS 1973 (113mA)
(!!!) (Best Value Single) 12AX7 Fisher Telefunken ribbed plate used/good 1960 era fair printing (Gm=1400/1600 and 0.9/1.1ma)
(!!!) (Best Value Single) 12AX7=ECC83 FISHER HOLLAND large "O" getter halo 1960 used/good (Gm=1550/1600 and .9/1.0ma)
(!!!) (Best Value Single) 12AX7=ECC83 FISHER HOLLAND large "O" getter halo 1961 used/good (Gm=1500/1600 and .9/.9ma)
(!!!) (Recommended Pair) 6HA5=6HM5=EC900 Amperex Holland "Globe Logo" NOS in white boxes 1971-1972 (10.4ma and 10.6ma)
(!!!) (Recommended Pair) 8417 GE NOS 1969 and 1986 same build (91ma and 94.6ma)
(!!!) (Recommended Single) 12AT7 Fisher Telefunken Germany <> bottom NOS 1964 (7ma/11ma) (recommended for mic)
(!!!) (Recommended Single) 12AT7 Fisher Telefunken Germany <> bottom NOS 1964 (9ma/6.5ma) (recommended for mic)
(!!!) (Recommended Single) EC92=6AB4 Siemens Halske NOS 1967 (9.2ma)
(!!!) (Single) 7868 RCA gray plate used/75% 1970 era (47.6ma)
(!!!) (Single) 7868 RCA gray plate used/75% 1970 era (47ma)
