(!!!!!) (Best Overall Pair) ECF80=6BL8 Telefunken Germany <> bottom NOS 1971 (best sound)
(!!!!!) (Best Pair) 12BH7A GE ribbed plates NOS 1967-1980 (11.0/10.8ma and 13/11ma)
(!!!!!) (Best Pair) ECF80=6BL8 Telefunken Germany <> bottom NOS 1971 (best sound)
(!!!!!) (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 PAIR) 7027A RCA NOS 1972 (69.2ma and 70.5ma)
(!!!!) (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) ECF80=6BL8 Telefunken Germany NOS 1971 (12.8/12.4ma)
(!!!!) (Best Value Pair #1) 12AX7=ECC83 Telefunken Germany <> bottom branded GAP/R Computor tube <> bottom smooth plates used/good 1964 era (0.9/0.8ma and 1.0/0.8ma)
(!!!!) (Best Value Pair #1) 12AX7A RCA gray ribbed plates NOS 1967-1973 (best tone) (0.9/0.9ma and 0.9/1.1ma) (Fender)
(!!!!) (Best Value Pair #2) 12AX7=ECC83 Telefunken Germany <> bottom branded GAP/R Computor tube <> bottom smooth plates used/good 1964 era (0.8/0.8ma and 0.8/0.8ma)
(!!!!) (Best Value Pair) ECF80=6BL8 Mullard rebranded GE NOS 1965-1966 (15/16.5ma and 11.2/11.8ma)
(!!!!) (Good Value Pair 1960's) 12AX7A RCA gray ribbed plates NOS 1967 (best tone) (1.0/0.8ma and 1.0/0.8ma) (1-2% matched)
