(!!!) (Best Sound) ECH81=6AJ8 Telefunken Germany <> bottom like new 1960's (6.3ma and 13ma) (highest mA and Gm)
(!!!) (Best Sound) ECH81=6AJ8 Telefunken Germany <> bottom used/good 1969 (5.8ma and 11.2ma)
(!!!) (Best Sound) ECH81=6AJ8 Telefunken Germany <> bottom used/tests like new 1960 era (6.0ma and 12.2ma)
ECH81=6AJ8 Amperex Italy NOS 1968 (6.4ma and 12.8ma)
ECH81=6AJ8 Tungsram Hungary branded Telefunken tests like new 1970's (6.5ma and 10.6ma) (strong Gm)
ECH81=6AJ8 Valvo Germany like new 1960 (6.3ma and 10.6ma)
