(!!!) (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)