(!!!!!) (INFORMATION) 6N1 or 6N1P (Best Sounding Substitutes = 6BK7B, 6BQ7A, 6BZ7)
(!!!!!) (Recommended Pair) 6BK7B RCA black plates NOS 1960's (9.5/10ma and 9.8/10.6ma)
(!!!!) (2nd Best GE Pair) 6BQ7A GE NOS "O" getter halo 1975-1976 (8.0/8.6ma and 8.3/8.3ma) (Schiit, DNA, Modwright)
(!!!!) (Best GE Pair) 6BQ7A GE NOS "O" getter halo 1975-1976 (9.2/10ma and 9/9.6ma) (Schiit, DNA, Modwright)
(!!!!) (Best GE Single 1957) 6BK7A GE gray plates NOS "U" getter 1957 (9.8/10.8ma)
(!!!!) (Best GE Single) 6BK7B GE gray plates NOS "U" getter 1974 (8.0/8.8ma)
(!!!!) (Recommended Pair) 6BK7B GE black plates NOS "U" getter halo 1960-1961 (7.2/7.2ma and 6/7ma) (Best 6N1P sub)
(!!!!) (Single) 6BK7B GE gray plates NOS "U" getter 1963 (6.2/5.4ma)
(!!!!) (Single) 6BK7B RCA NOS "U" getter 1950's (7.5/8.5ma)
(!!!!) (Single) 6BK7B Tungsol branded RCA "U" getter 1957 (10/14ma)
(!!!) (Recommended Pair) 6BK7B Tungsol black plates NOS "O" getter 1960 era (9.5/12ma and 9.8/10.5ma)
(!!!) (Recommended Pair) 6BK7B Tungsol black plates NOS "O" getter 1960's (7.5/8.6ma and 8.2/9.4ma)
(!!!) (Recommended Pair) 6BK7B Tungsol gray plates NOS "O" getter 1960's (10/11ma and 10.6/13.2ma)
(!!!) (Recommended Single) 6BK7A Raytheon black plates NOS "D" getter 1950's (7.2/8.2ma) (great sub for 6N1P)
(!!!) (Recommended Single) 6BK7B Tungsol gray plates NOS 1960's (8.0/9.8ma) (great sub for 6N1P)