(!!!!!) (BEST SINGLE) 6X4 SER = LM Ericsson Sweden "D" getter NOS 1950's (55/40 and 55/40) 1% diode balance
(!!!!!) (Good Value Single) 6X4 SER = LM Ericsson Sweden "D" getter NOS 1950's (55/40 and 56/40) 1-2% balance
(!!!!) (Best Overall Pair) 6112 Philips JAN 1980's (1.2/1.2ma and 1.1/1.5ma) (Highest mA and Gm) (Audio Note, Musical Fidelity)
(!!!!) (Best Overall Pair) 6112 Philips JAN 1985 (1.0/1.0ma and 0.9/1.1ma) 1-3% matched (Audio Note, Musical Fidelity)
(!!!!) (Best Pair) 6X4 SER = LM Ericsson Sweden "D" getter NOS 1950's 1-2% matched (54-54/40 and 54-55/40)
(!!!!) (Best Pair) 6X4 SER = LM Ericsson Sweden "D" getter NOS 1950's 1-2% matched (54-55/40 and 54-55/40 x 2 tubes)
(!!!!) (Best Pair) ECL82=6BM8 Pope and Valvo Holland 1960-1966 (2.1/36ma and 2.1/34ma)
(!!!!) (Best Quad #1) 6SH7 GE metal can NOS 1976 (10.6, 10.6, 11.0, 11.0mA)
(!!!!) (Best Single) 6X5GT Philips Miniwatt Australia NOS 1940's (53/40 and 53/40)
(!!!!) (Best Single) JAN-5687WB GE NOS 1972 (34.6/35.6ma)
(!!!!) (Best Sylvania Pair) 6X5GT Sylvania NOS 1951 (50-53/40 and 52-53/40)
(!!!!) (Best Value Single) 6X5GT Philips Miniwatt Australia NOS 1940's (49/40 and 50/40)
(!!!!) (Good Value Pair) 5687WB GE used/good 1970 era (25/27ma and 26.5/26ma)
(!!!!) (Good Value Pair) 5687WB GE used/good 1970 era (26.2/27ma and 25.6/28ma)
(!!!!) (Good Value Pair) 5687WB GE used/good 1970 era (26/27ma and 26.6/27.8ma)
(!!!!) (Good Value Pair) 6X4 SER = LM Ericsson Sweden "D" getter NOS 1950's 1-2% matched - slightly faded top getters (54-55/40 x 2 tubes)
(!!!!) (Good Value Pair) JAN-5687WB GE used/good 1970 era (29.5/31ma and 29.2/29.6ma)
(!!!!) (Good Value Single) 6X4 SER = LM Ericsson Sweden "D" getter NOS 1950's (46/40 and 46/40)
(!!!) (BEST 6BM8 - best sound) ECL82=6BM8 Telefunken Germany <> bottom NOS 1967 (2.3/59ma)
(!!!) (Best Overall Pair 1943) 6X5GT=VT-126B RCA black plates NOS 1943 (62-62/40 and 60-62/40)