(!!!) (Best Value) 12AT7 Amperex Mullard UK NOS 1971 (7.5/11.2ma)
(!!!!!) (BEST Pair) ECC81=12AT7 Mullard UK NOS 1970-1973 (9.0/9.2ma and 8.8/9.8ma)
(!!!!!) (Best 448A Pair) 448A Western Electric smooth top used/test like new 1965-1968 (42.5ma and 45.5ma) (Matched on Amplitrex)
(!!!!!) (BEST GE PAIR 1969) JAN-5751 GE double mica gray plates NOS 1969 (1.9/2.2ma and 2.1/2.1ma) 1-3% matched pair
(!!!!!) (Best GE Pair) 6021 GE 5 Star Rated NOS "D" getter halo 1957 in GE 5 Star Boxes (1-3% matched) (5.5/5.8ma and 5.4/5.9ma)
(slightly microphonic) 12BH7 GE Zenith NOS "U" getter 1953 (10.0/10.6ma)
(!!!!!) (BEST MATCHED QUAD) JAN-CW-231D Western Electric NOS 1953 (1.8/1.8/1.8/1.8ma) 1% matched
(!!!!!) (Best Overall Pair) 311B Western Electric NOS 1956 and 1964 (35ma and 36ma)
(!!!!!) (Best Overall Pair) 6C10 GE rebranded RCA NOS 1960's (Ampeg / Fender) (1.6ma/1.5ma/1.4ma) and (1.5ma/1.8ma/1.4ma)
(!!!!!) (Best Overall Pair) 6C10 GE rebranded RCA NOS 1960's (Ampeg / Fender) (1.6ma/1.6ma/1.3ma) and (1.6ma/1.3ma/1.7ma) (Best Pair in the World)
(!!!!!) (Recommended Pair) ECC81=12AT7 Mullard UK NOS 1966-1972 (9.5/13.0ma and 9.7/11.5ma)
(!!!!!) (Best Pair) JAN-5691 Philips by Sylvania black plates NOS 1985 (2.3/2.6mA and 2.3/2.4mA) (Best 6SL7GT sub) (same internals as 5691 red base)
(!!!!!) (Best Pair) JAN-5691 Sylvania black plates NOS 1977 (2.1/2.2mA and 2.1/2.3mA) (Best 6SL7GT sub) (same internals as 5691 red base)
(!!!!!) (Best Pair) JAN-5691 Sylvania black plates NOS 1979 (2.0/2.1mA and 2.1/2.1mA) (Best 6SL7GT sub) (same internals as 5691 red base)
(!!!!!) (Best Quad) JAN-5691 Sylvania black plates NOS 1979 1-3% matched (Cary, Rogue) (Best 6SL7GT sub) (same internals as 5691 red base)
(!!!!!) (Best Siemens Single 1969) 6922 Siemens Halske Germany NOS 1969 (16.6/18.4ma) (High Ma and Gm)
(!!!!!) (Best Value 1963) 12AX7 Knight Mullard UK low hours/like new 1963 (1.0/0.9ma and Gm=1600/1600) (161 series) (Fender, Marshall, Gibson)
(!!!!!) (Best Single 1967) 6DJ8=ECC88 Philips Miniwatt Holland "o" getter 1967 (16/18.8ma)
(!!) (sold out) 6DJ8 Amperex Bugle Boy Holland NOS 1966 (18.6/19.0ma) (High Ma and Gm)
(!!!!!) (Best Single) 6DJ8=ECC88 Philips Miniwatt Holland "O" getter 1965 (21/23ma) (Highest mA and Gm)