(!!!!!) (Best Pair #2) 5687WA and 5687WB GE black plates like new 1970's (39/38.5ma and 37/41ma) (Highest Ma and Gm)
(!!!!!) (Best Pair) 5U4GB CBS NOS 1950's double "D" getters (59-59/40 and 58-60/40)
(!!!!!) (BEST PAIR) PCC88=7DJ8 RFT East Germany branded Tesla NOS 1980 era (17.8/17.6ma and 18.0/18.8ma) (highest mA and Gm)
(!!!!!) (Best Single) PCC88=7DJ8 Siemens Germany branded Pope NOS 1979 (14.2/14.5ma)
(!!!!!) (BEST SYLVANIA PAIR) 6550 Sylvania welded plates branded RCA 1978 low hours/like new (124ma and 130ma)
(!!!!!) (Best Tungsram Single) ECC83=12AX7A Tungsram Hungary branded RCA NOS 1970's (Gm=2000/2300) (1.7/1.8ma) (Highest mA and Gm)
(!!!!!) (Best Value Single) JAN-5691 Philips by Sylvania black plates NOS 1985 (2.4/2.6ma) (Best 6SL7GT sub)
(!!!!!) (Recommended Pair) 5U4GB HYTRON NOS 1960 "O" getter halos (56-58/40 and 57-58/40)
(!!!!!) (Recommended Pair) 5U4GB HYTRON NOS 1960 "O" getter halos (60-64/40 and 60-66/40)
(!!!!!) (recommended pair) JAN-5691 Sylvania black plates NOS 1977 (2.8/3.1mA and 2.5/2.9mA) (Best 6SL7GT sub) (same internals as 5691 red base)
(!!!!!) (Recommended Pair) JAN-5691 Sylvania black plates NOS 1979 (1.9/1.9mA and 1.9/2.1mA) (Best 6SL7GT sub) (same internals as 5691 red base) 1-3% matched
(!!!!!) (Recommended Pair) PCC88=7DJ8 Philips Holland NOS 1973 (11.5/11.0ma and 11.5/12ma) (Similar sound to 6DJ8 Holland) (sweet sound)
(!!!!!) (Recommended Single) ECC83=12AX7A Tungsram Hungary branded RCA NOS 1970's (Gm=1700/1900) (1.0/1.4ma)
(!!!!!) (RecommendedPair) JAN-5691 Philips by Sylvania black plates NOS 1984-1985 (2.0/2.2mA and 2.1/2.4mA) (Best 6SL7GT sub) (same internals as 5691 red base) 1-3% matched
(!!!!) (2nd Best Amperex PQ Single) 6922 Amperex PQ USA NOS 1962 (14.5/16.2ma) (Audio Research, Nova)
(!!!!) (2nd Best GE Pair) 5U4GB GE NOS 1977 (62-61/40 and 60-62/40 x 2 tubes)
(!!!!) (2nd Best Pair 1968) PCC88=7DJ8 Philips Holland "O" getter NOS 1968 (12.6/14.2ma and 15/12ma) (sweet sound)
(!!!!) (2nd Best Pair) GB-6136=6AU6 Sylvania Gold Brand Gold Pins NOS 1960's (6.8ma and 6.9ma) (Same Gm)
(!!!!) (2ND BEST RCA PAIR) 6EU7 RCA NOS 1970-1972 (44-50/32 and 43-49/32)
(!!!!) (3rd Best Pair 1968) PCC88=7DJ8 Philips Holland "O" getter NOS 1968 (13.2/10.4ma and 10.4/11.2ma) (sweet sound)