(!!!!!) (Best Overall Pair) ECF80=6BL8 Telefunken Germany <> bottom NOS 1971 (best sound)
(!!!!!) (Best Overall Single) ECC82=12AU7 Telefunken Diamond Bottom <> smooth plates NOS 1965 (10.2/10.2ma) 1-2% section balance
(!!!!!) (Best Overall Single) ECC82=12AU7 Telefunken Diamond Bottom <> smooth plates NOS 1970 (14.4/14.2ma) (Highest mA and Gm)
(!!!!!) (Best Pair) ECF80=6BL8 Telefunken Germany <> bottom NOS 1971 (best sound)
(!!!!!) (Good Value Pair - for Audio Aero) 6021=CV3986 Mullard UK Mitcham NOS 1969 (4.4/4.6ma and 4.5/4.8ma) (1-3% matched)
(!!!!) (Best Holland Pair) ECC82=12AU7 Philips Holland NOS 1971 (10.8/11ma and 10.0/10.4ma)
(!!!!) (Best Pair) ECC82=12AU7 Philips Holland NOS 1972 (12/12ma and 11.2/11.8ma) (Highest mA and Gm)
(!!!!) (Best Siemens Pair) EL84 Siemens Halske Germany used/test like new 1971 (48.2ma and 48.5ma) (High Gm)
(!!!!) (Good Single) E88CC=6922 Philips SQ Holland used/tests like new 1968 (13.0/12.6ma) (3D MIDS, low noise) (same Gm)
(!!!!) (Holland Single) 12AU7 Philips Holland NOS 1971 dimpled disc halo (10.2/10.6ma)
(!!!!) 6336A Tungsol branded Heintz and Kaufman 1960's (62/76ma) ***
(!!!) (Best Overall Single) E81CC=12AT7 Siemens double mica NOS 1976 (11.4/12ma) (high Ma and Gm)
(!!!) (Best Siemens Pair) EL84 Siemens Halske Germany 1966-1969 (40ma and 42.5ma)
(!!!) (Best Value Pair) 807 RCA black plate used/good 1956-1957 getters like new (58.2ma and 56.5ma)
(!!!) (Good Value) 6021=CV3986 Mullard UK Mitcham plant NOS 1971 (4.2/4.4ma and 4.2/4.4ma)
(!!!) (Recommended Pair) 6005W Sylvania JAN black plate clear glass NOS 1971 (45.8ma and 46.6ma)
(!!!) (Recommended Pair) 6005W Sylvania JAN black plate clear glass NOS 1971-1972 (41ma and 41.2ma) 1% matched
(!!!) (Recommended Pair) 6AQ5A Sylvania black plate NOS 1970's (50.5ma and 52ma)
(!!!) (Recommended Pair) ECC85=6AQ8 RCA Heerlen Holland NOS 1968 (21/16.5ma and 18.5/15.5ma) (close Gm)
(!!!) (Recommended Single) CV491=12AU7=ECC82 Brimar England NOS ribbed plates 1974 (9.4/9.2ma)