(!!!!!) (2nd Best Pair) 6BQ7A RCA black plates NOS "D" getter 1958 (10/12.2ma and 10.5/13.5ma)
(!!!) (Recommended Pair) 6BQ7A RCA black plates NOS 1962-1972 same build (9.5/11.5ma and 9.2/11ma)
(!!!) (Recommended Single) 6BQ7A RCA black plates NOS 1977 (15/20ma)
(!!!) 6BQ7A RCA black plates NOS 1970 era (14.0/15.2ma)
5BK7A GE branded GM Delco black plates "U" getter 1950's (12/13ma)
5BQ7A Dumont by GE gray plates NOS 1960's (6 in stock)
5BQ7A GE gray plates NOS large "U" getter halo 1961 (3 in stock)
5BQ7A RCA black plates NOS "D" getter 1950's (5 in stock)
6BK7B Philco by Sylvania NOS 1960 (13.2ma/15.2ma)
6BQ7A RCA black plates branded Westinghouse NOS "D" getter halo 1950's (7.5/8.0ma)
(!!!!!) (INFORMATION) 6N1 or 6N1P (Best Sounding Substitutes = 6BK7B, 6BQ7A, 6BZ7)
(!!!) (Recommended Single) 6BK7A Tungsol black plates NOS "U" getter 1956 (8.6/9.6ma) (great sub for 6N1P)
(!!!!!) (Best Value Pair) 6BQ7A RCA black plates NOS "D" getter 1958-1959 (7.6/9ma and 7/9.6ma)
(!!!) (Recommended Pair) 6BK7B Tungsol black plates NOS "O" getter 1960's (7.5/8.6ma and 8.2/9.4ma)
(!!!) (Recommended Pair) 6BK7B Tungsol black plates NOS "O" getter 1960 era (9.5/12ma and 9.8/10.5ma)
(!!!) (Recommended Pair) 6BK7B Tungsol gray plates NOS "O" getter 1960's (10/11ma and 10.6/13.2ma)
(!!!) (Recommended Single) 6BK7B Tungsol gray plates NOS 1960's (8.0/9.8ma) (great sub for 6N1P)
(!!!!!) (Recommended Pair) 6BK7B RCA black plates NOS 1960's (9.5/10ma and 9.8/10.6ma)
(!!!!) (Best Single 1970) 6BK7B RCA black plates NOS 1970 (10.6/11.2ma)
(!!!!) (Recommended Pair) 6BK7B GE black plates NOS "U" getter halo 1960-1961 (7.2/7.2ma and 6/7ma) (Best 6N1P sub)