(!!!!) (Recommended Pair) 6EW7 Hitachi Japan branded Westinghouse BIG BOTTLE NOS 1970-1972 (5.8/6.1ma and 68/62ma)
(!!!!) (Best Pair) 6EW7 Hitachi Japan branded Westinghouse BIG BOTTLE NOS 1970-1972 (5.2/5.4ma and 55/56ma)
(!!!!) (Recommended Pair) 6EW7 Hitachi Japan branded Westinghouse BIG BOTTLE NOS 1970-1972 (4.0/4.4ma and 53/55ma)
(!!!) (BEST PAIR) 6EW7 GE BIG BOTTLE gray plates NOS 1965-1966 (5.2/34.5ma and 5.7/38ma)
(!!!) (Recommended pair) 6EW7 Sylvania BIG BOTTLE NOS 1960's (4.8/5.2ma and 52/44ma)
(!!!) 6DE7 GE Canada black plates NOS 1967 (4.6/42ma) (Woo Audio)
(!!!) 6DE7 Sylvania black plates "U" getter NOS 1950's (8/31ma) (Woo Audio)
(!!!) 6DE7 Sylvania branded GE black plates NOS 1968 (5.1/35ma) (Woo Audio)
(!!) (Best Single) 6EW7 Sylvania BIG BOTTLE NOS 1960's (7.8/56ma) (highest Ma and Gm)
(!!) (Recommended Single) 6EW7 Sylvania BIG BOTTLE black plates NOS around 1960 (7.8/50ma)
(!!) 6EW7 Sylvania BIG BOTTLE NOS 1960's (3.3/44ma)
(!) (#2 6EW7 Single Tube) 6EW7 GE Japan BIG BOTTLE NOS 1960's (5.0/37ma)
(!) 6DE7 GE Admiral black plates NOS 1965 (4.5/27ma) (Woo Audio)
6DE7 GE NOS 1960's (6.5/36ma)
6DE7 RCA NOS 1960's (4.5/34ma)
6DE7 RCA NOS 1966 (5.2/40ma)
6DE7 Sylvania NOS 1960's (5.3/27ma)
6EW7 Daystrom by RCA BIG BOTTLE used/70-80% 1960's (4.5/32ma)
6EW7 RCA BIG BOTTLE black plates NOS 1961 era (5.4/42ma)
6EW7 RCA BIG BOTTLE NOS 1960's (4/35ma)
