(!!) (#1 6BL7GTA PAIR - best sound) 6BL7GTA RCA NOS early 1960's (38/40ma and 37/39ma)
(!!) (#1 6BL7GTA Pair) 6BL7GTA GE NOS 1960-1961 same build (46/51ma and 47/53ma)
(!!) (#1 6BL7GTA) 6BL7GTA GE NOS and like new 1960's same build (46/51ma and 43/52ma)
(!!) (#1 6BL7GTA) 6BL7GTA GE rebranded CBS "U" getter NOS 1960 (37/38ma) best section balance
(!!) (#2 6BL7GTA Pair) 6BL7GTA Sylvania NOS 1960's (32/36ma and 36/38ma)
(!!) (#2 6BL7GTA RCA Pair) 6BL7GTA RCA NOS 1960's (34/36ma and 36/41ma)
(!!) (#2 6BL7GTA Sylvania Pair) 6BL7GTA Sylvania NOS 1960's (33/40ma and 34/36ma)
(!!) (#3 6BL7GTA PAIR) 6BL7GTA GE gray plates NOS 1960's (42/52ma and 48/49ma)
(!!) (#3 6BL7GTA Pair) 6BL7GTA GE NOS and like new 1960's same build (41.5/43ma and 44/46ma)
(!) (#1 6BL7GTA used/pair) 6BL7GTA GE black plates used/good 1960-1965 (34.5/39ma and 33/33ma)
(!) (#1 6BL7GTA) 6BL7GTA GE rebranded Raytheon "D" getter NOS 1950's (39/43ma)
(!) 6BL7GT Sylvania rebranded Tungsol "D" getter halo NOS 1955-1956 (37/38ma)
6BL7GT Sylvania used/75-80% 1953 (30/32.5ma)
6BL7GTA GE branded Admiral 1964 (38/40ma) tight triode section balance
6BL7GTA GE gray plates NOS around 1970 (47/53ma)
6BL7GTA Sylvania used/good 1960's (31/33ma)
