(!!!!!) (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 PAIR) 7AF7 Sylvania NOS gray round plates NOS 1950-1958 (8.5/8.7ma and 9.2/9.2ma) 1-5% matched (same Gm)
(!!) (BEST PAIR) 7C5 Sylvania branded International NOS 1960's (42ma and 43.5ma) (LOKTAL BASE 6V6GT)
(!!) (Best Single) 7AF7 Sylvania branded Hytron NOS round black plates NOS 1952 (9.6/9.4ma) 1-3% section balance
(!!) (Best Single) 7N7 Sylvania branded Philco NOS parallel black plates 1940's (7.5/7.9ma)
(!!) (Recommended PAIR) 7C5 Sylvania branded International NOS 1960's (39ma and 40ma) (LOKTAL BASE 6V6GT)
(!!) 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 PRICE) 7E5=1201 US Brands NOS (4 tubes for $14.99)
(!) (Best Single) 7N7 Sylvania NOS 1960 era (10.8/11.2ma)
(!) (Good Single) 7N7 Sylvania branded GE NOS 1961-1962 (7.5/8.3ma)
(!) (Recommended Single) 7F7 Sylvania rebranded JAN-CBRZ-7F7 round gray plates used/like new 1940's (2.9/3.2ma) (highest testing single)
(!) (SINGLE) 7N7 Sylvania TALL BOTTLE branded Hytron parallel black plates chrome top NOS 1952 (6.6/8.3ma)
(!) (SINGLE) 7N7 Sylvania TALL BOTTLE branded Hytron parallel black plates chrome top NOS 1952 (7.6/7.8ma)
(BEST PRICE) 7A5 NOS (4 for $11.99)
(BEST PRICE) 7A6 US Brands NOS (4 tubes for $11.99)
(BEST PRICE) 7B5 US Brands NOS (4 tubes for $11.99)
(BEST PRICE) 7B8 NOS (4 tubes for $11.99)
(BEST PRICE) 7C4=1203A US Brands NOS (diode) (4 for $11.99)
(BEST PRICE) 7C5 US Brands used/good mostly 1950's (4 tubes for $16.99)