(!!!) (Best RCA Pair) 6BL7GTA RCA Rauland NOS 1961 same date codes (35/35.5ma and 36/37.2ma) 1-3% matched
(!!!) (Best Sylvania Pair) 6BL7GT Sylvania wide tall black plates triple mica "D" getter NOS 1950 (40/52ma and 43/53ma)
(!!!) (Recommended Sylvania Pair) 6BL7GTA and 6BL7GT Sylvania rebranded RCA and Silvertone NOS 1950's triple mica and D getter (39/41ma and 38/39ma)
(!!) (#1 6BL7GTA) 6BL7GTA GE NOS and like new 1960's same build (46/51ma and 43/52ma)
(!!) (#2 6BL7GTA Pair) 6BL7GTA Sylvania NOS 1960's (32/36ma and 36/38ma)
(!!) (#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)
(!!) 6BL7GT Sylvania NOS "D" getter 1953 (36.6/37.5ma)
(!) (#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)
