(!!!!!) (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 "O" getter 1970's (12.8/13.6ma)
(!!!) 6BQ7A RCA black plates NOS "O" getter 1970's (14.5/22ma)
(!!!) 6BQ7A RCA black plates NOS 1970 era (14.0/15.2ma)
(!!!!) (Best Single) 6BK7B Sylvania branded RCA "D" getter 1958 (13.4/13.5ma) 1-2% section balance
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 Pair) 6BQ7A RCA black plates NOS "D" getter 1958-1959 (8.8/9.0ma and 8.8/9.0ma) 1-2% matched
(!!!!) (Best Pair) 6BQ7A RCA black plates NOS "D" and "U" getter 1956 and 1958 (8.5/9.7ma and 8.2/9.8ma) 1-3% matched
(!!!!!) (Best Value Pair) 6BQ7A RCA black plates NOS "D" getter 1958-1959 (7.6/9ma and 7/9.6ma)
(!!!) (Recommended Pair) 6BQ7A RCA black plates NOS 1964 (11.5/14ma and 12.5/13ma)
(!!!!!) (Best Overall Pair) 6BK7B RCA black plates "U" getter NOS 1957 (10.2/10.8ma and 10.6/11ma)