(!!!!!) (Best Overall Pair) 7N7 Sylvania chrome top NOS 1956-1957 1-3% matched (8/9ma and 8.6/8.4ma) (best 6SN7 sub using adapter sockets)
(!!!!!) (Best Value Pair) 6SN7GTB Sylvania "chrome top" NOS and like new 1956 (8.1/8.6ma and 7.8/8.6ma) (strong Gm)
(!!!!) (Best Single) 6SN7GTA Sylvania Philco "Chrome Top" short bottle NOS 1954 (7.8/8.0ma) 1-3% section balance
(!!!!) (Best Sylvania Pair) 6X5GT Sylvania NOS 1951 (50-53/40 and 52-53/40)
(!!!!) (Good Value Pair) 8SN7GTB Sylvania GM Delco "chrome top" NOS 1957 same build (6.4/7.2ma and 7.4/6.2ma) (Schiit Freya, Rogue, Modwright OPPO, Cary) (1-5% matched)
(!!!!) (Recommended Pair) 6SN7GTB Sylvania chrome top gray plates 1950's used/very good (9.6/9.0ma and 8.6/8.2ma) (Gm like new)
(!!!) (Recommended Pair) 6X5GT GE NOS 1961-1963 (50-50/40 and 49-49/40 x 2 tubes)
(!!!) (Recommended Single) 6SN7GTB Sylvania NOS 1960's (7.2ma and 6.6ma)
(!!!) (Recommended Single) 6SN7GTB Sylvania used/tests like new 1960's (8.2ma and 7.6ma)
(!!!) (Recommended Single) 6X5GT Sylvania Silvertone NOS 1945 (52/40 and 53/40)
(!!!) (Single) 6X5GT Sylvania Philco NOS 1945 (53/40 and 56/40)
(!!) (Best Single) 6AH4GT Sylvania branded Hytron "D" getter NOS 1954 (48ma) (Highest mA and Gm)
(!!) (Best Single) 7N7 Sylvania branded Philco NOS parallel black plates 1940's (7.5/7.9ma)
(!!) 6SN7GTA Sylvania "chrome top" tall bottle used/good 1950 era (6ma/6ma) 1-2% section balance
(!!) 6V6GT Sylvania chrome top NOS 1956 (41.6ma)
(!!) 7N7 Sylvania branded Philco used/good short bottle parallel gray plates 1948 (7.2/7.6ma)
(!!) 7N7 Sylvania NOS 1960's (8.6/10.2ma)
(!) (Best Single) 6AH4GT Tungsol ITT NOS 1960's (34ma)
(!) (Best Single) 7N7 Sylvania NOS 1960 era (10.8/11.2ma)
(!) (Good Single) 7N7 Sylvania branded GE NOS 1961-1962 (7.5/8.3ma)
