(!!!!) (Best Pair) 6U8A=6678 GE NOS 1968 same date codes (14.0/14.2ma and 12.2/12.8ma) 1-3% matched
(!!!!) (Best Sylvania Pair) 6U8A Sylvania NOS 1970 era (17.0/16.4ma and 10.2/10.4ma)
(!!!!) (Oldest Pair) 6U8A GE NOS 1962 (19.2/16.8ma and 11.8/10.5ma) (Close Gm)
(!!!!) (Recommended Pair) 6U8A GE NOS 1973-1976 (19/18.8ma and 10/9.8ma)
(!!!!) (Recommended Pair) 6U8A GE NOS 1974-1977 (17.2/17.8ma and 8.6/8.4ma) 1-3% matched
(!!!!) (Recommended Pair) 6U8A Philips by Sylvania NOS 1986 (15.5/16.0ma and 8.4/8.0ma)
(!!!!) (Recommended Pair) 6U8A Philips by Sylvania NOS 1986 (16.4/16.8ma and 9.2/9.2ma)
(!!!!) (Recommended Pair) 6U8A Philips by Sylvania NOS 1986 (17.2/17.6ma and 8.4/8.6ma)
(!!!) (Best Single) 6U8A GE Motorola NOS 1977 (15.2ma/9ma)
(!!!) 6U8A Raytheon black plates NOS "U" getter halo 1962 (17ma and 8ma)
(!!) (Best Telefunken) ECF82=6U8 Telefunken Germany <> bottom NOS 1968 (13ma triode and 9.6ma pentode)
(!!) (Best Telefunken) ECF82=6U8 Telefunken Germany <> bottom NOS 1969 (24ma triode and 9.4ma pentode)
(!!) (Recommended Single) 6U8A GE Amperex NOS 1974 (13.5ma/10.2ma)
(!!) (Recommended Single) 6U8A GE NOS 1977 (14.2ma/10ma)
(!!) 6U8=ECF82 Tungsram Hungary rebranded Haltron NOS 1970's (14.3ma and 7.6ma)
(!!) 6U8A Westinghouse NOS 1967 (17.8ma and 9.5ma)
(!!) 6U8A Westinghouse NOS 1967 (24ma and 7.5ma)
(!!) ECF82=6U8 Telefunken Germany <> bottom NOS 1968-1969 faded printing (14ma triode and 8.6ma pentode)
(!) (BEST SINGLE) 6U8A Sylvania NOS 1970 era (20ma/17ma)
(!) (Recommended SINGLE) 6U8A Sylvania NOS 1960's (19.8ma/10.6ma)
