(!!!!!) (Best Audio Pair) PCC88=7DJ8 Philips Holland NOS 1970 (12.2/12.5ma and 12.6/13.5ma) (Similar sound to 6DJ8 Holland)
(!!!!!) (Best Overall Single) JAN-5691 Sylvania black plates NOS 1977 (2.8/3.1mA) (Same Gm) (Best 6SL7GT sub) (same internals as 5691 red base)
(!!!!!) (Best Pair) 5U4GB CBS NOS 1950's double "D" getters (59-59/40 and 58-60/40)
(!!!!!) (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 PAIR) PCC88=7DJ8 RFT East Germany branded Tesla NOS 1980 era (16.2/16.0ma and 15.2/15.4ma)
(!!!!!) (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=12AX7 Tungsram Hungary NOS 1980 (Gm=1900/1900) (1.2/1.5ma)
(!!!!!) (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 Pair) JAN-5687WA Sylvania black plates used/test like new 1967-1970 era (43.6/47ma and 46.8/44.2ma) (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) EL34 Philips Mullard XF2 single halo "O" NOS and like new 1969-1973 (90.8ma and 95ma) (can make a quad with another XF2 pair)
(!!!!!) (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)
(!!!!!) (Recommended Single) JAN-5691 Sylvania black plates NOS 1979 (2.2/2.4mA (Best 6SL7GT sub) (same internals as 5691 red base)
(!!!!!) (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
