(!!!!) (Best Pair) 6DN7 GE branded RCA NOS 1968 (35/7ma and 36/7.5ma)
(!!) (BEST SINGLE) 6DN7 GE branded RCA NOS 1960's (64ma and 7.2ma)
(!!!) (BEST PAIR) 6DN7 GE branded Tungsol and RCA NOS black plate/gray plate 1960 era (40ma and 8.5ma and 40ma 7.7ma)
(Best Single) 6DN7 Sylvania NOS 1960's (60ma/8.3ma)
(BEST SINGLE) 6DN7 RCA NOS 1968 (38ma and 10.2ma)
(!!!!) (BEST PAIR) 6DN7 GE branded GE and CBS NOS 1959 same build (46.4/46.5ma and 8/9ma)
6DN7 GE branded RCA NOS 1962 (46.6ma and 8.2ma)
6DN7 Philco by GE NOS 1963 (33ma and 9.2ma)
6DN7 RCA Mexco coin-base same internals as Sylvania NOS 1970's (40ma and 8.5ma)
6DN7 Sylvania NOS 1970 era (39ma and 7.5ma)
(!!!!) (Recommended Pair) 6DN7 RCA NOS 1968 same date codes (39ma/7ma and 41ma/8.5ma)
(!!!!) (Best Pair) 6DN7 RCA NOS 1968 same date codes (33ma/10.2ma and 33ma/10.1ma)
(!!!!) (Recommended Pair) 6DN7 RCA NOS 1968 same date codes (30ma/10.2ma and 31ma/9.7ma)
