(!!!!!) (Best Pair) 12BH7A GE ribbed plates NOS 1967-1980 (11.0/10.8ma and 13/11ma)
(!!!!!) (Good Value Pair) 12BH7A GE ribbed plates NOS 1966-1974 (7.0/9.4ma and 7.0/10.5ma)
(!!!!!) (Recommended Pair) 12BH7A GE gray oval plates NOS 1965 (11/15.5ma and 13.6/11.6ma)
(!!!!!) (Recommended Pair) 12BH7A GE NOS gray oval plates large "U" getter 1957-1960 (10/12ma and 10.2/14.2ma) (McIntosh, Quicksilver, Art Audio)
(!!!!) (Best GE single 1968) 12BH7A GE NOS 1968 (15/16ma) 1-2% section balance
(!!!!) (Best Overall Single) 12BH7A Westinghouse gray ribbed plates NOS 1967 (10.6/10.8ma) (Same Gm) (similar to RCA)
(!!!!) (Best Overall Single) GZ37 Mullard UK NOS 1966 (52/40 and 52/40) 1% section balance
(!!!!) (Best Pair 1966) CV378=GZ37 Mullard NOS 1966 (51-51/40 x 2 tubes) 1% matched
(!!!!) (Best Pair) CV378=GZ37 Mullard NOS 1966 (50-51/40 x 2 tubes) 1% matched
(!!!!) (Best Single) 12BH7 GE NOS gray oval plates "U" getter 1953 (13.8/14.2) (Quicksilver, Wells, Doshi, McIntosh)
(!!!!) (Best Single) 12BH7 Sylvania Silvertone black oval plates "D" getter NOS 1954 (14.4/12.2ma)
(!!!!) (Best Single) 12BH7A RCA gray plates NOS 1970 (10.6/10.2ma)
(!!!!) (Best Single) 12BH7A RCA NOS 1960's (11.6/12.6ma)
(!!!!) (Best Single) 12BH7A Tungsol black plates "O" getter halo 1960 era (11.0/11.6ma)
(!!!!) (Best Single) CV378=GZ37 Mullard UK NOS 1966 (53/40 and 54/40)
(!!!!) (Best Single) CV378=GZ37 Mullard UK NOS 1967 (50/40 and 50/40) 1% section balance
(!!!!) (Good Value Pair) 12BH7A GE NOS gray oval plates "o" getter halo 1961-1965 (7.2/6.6ma and 8.4/6.8ma)
(!!!!) (Good Value Pair) 12BH7A RCA gray plates NOS and like new 1970's (10.6/11.0ma and 12.0/10.0ma) (close Gm) (Art Audio, Manley Mac, VTL)
(!!!!) (Good Value Pair) 12BH7A Sylvania NOS 1960's (9.6/14ma and 10.5/15.4ma)
(!!!!) (Recommended Single) CV378=GZ37 Mullard UK NOS 1967 (52/40 and 54/40) 1-3% section balance