(!!!!!) (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) JAN-CTL6SL7WGT Tungsol NOS brown base gray ribbed plates 1961-1965 (2.1/2.2ma and 2.1/2.3ma) (low noise - very smooth sound) (phono grade)
(!!!) (Good Value Pair) 6SL7GT GE NOS round chrome plates 1969 (1.8/1.9ma and 1.9/2.0ma) (same Gm)
(!!!) (Good Value Pair) 6SL7GT Sylvania gray round plates chrome top used/good 1949-1954 (2.3/1.9ma and 2.4/2.1ma)
(!!!) (Slightly Microphonic Single) CV1985=6SL7GTY Brimar UK tests like new 1950's (2.2/2.2ma)
(!!!) 6SL7WGT Sylvania branded Raytheon 5691 brown base round black plates "D" getter halo used/good 1950's (1.6/1.8ma)
(!!!) (Best Value) VT-229=6SL7GT Sylvania round black plates used/like new 1940's (2.5/2.7ma) (Gm like new)
(!!) (Best Value) VT-229=JAN-CHS-6SL7GT Sylvania NOS white printing 1944-1945, hairline crack in base, mis-matched sections in white box (2.6/3.4ma)
(!!) (slightly microphonic) 6SL7GT RCA NOS 1950 (2.2/2.3ma) 1-2% section balance
(!!) (slightly microphonic) 6SL7GT RCA NOS black plates gray coated glass 1952 (2.8/2.8ma) 1% section balance
(!!!) (Recommended Pair) 5691 RCA red base gray plates 1968-1974 (2.2/2.4ma and 2.1/2.3ma)
(!) (slightly microphonic) 6SL7GT=VT-229 RCA round black plates like new 1942-1945 era (2.4/2.6ma)
(!) (slightly microphonic) JAN-CRC-6SL7GT RCA NOS black plates 1951 tilted glass (2.0/2.2ma)
(!) 6SL7GT RCA burgundy base NOS 1951 (1.7/1.8ma)
(!!) (Best Pair) JAN-CHS-6SL7WGT Sylvania brown base "square getter halo" like new faded printing (2.4/2.6ma and 2.4/2.4ma) 1-3% matched
(!!!) (Recommended Single) 6SL7GT Ken Rad NOS 1945 era (2.1/2.3ma)
(!!!) (Recommended Single) 5691 RCA Red Base black plates used/good 1959 (2.3/2.0ma)
(!!!!) (Best RCA Pair) VT-229=6SL7GT RCA round black plates NOS 1942 (2.8/2.9ma and 2.5/2.6ma)
(!!!!!) (BEST VALUE PAIR) 6SL7GT GE branded RCA coin-base 1970's series filament - round silver/chrome plates (1.8/1.8ma and 2.0/1.8ma) 1-5% matched
(!!!!!) (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