(!!!) (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)
(!!!) (Recommended Single) 6BQ7A RCA black plates NOS 1962 (10/14ma)
(!!!) (Recommended Single) 6BZ7 RCA black plates "U" getter NOS 1957 (9.0/9.4ma)
(!!!) (Recommended Single) 6BZ7 RCA black plates large "O" getter NOS 1965 (13.0/14.2ma)
(!!!) 6BZ7 RCA black plates "U" getter NOS 1954 (9.6/12.2ma)
(!) (BEST SINGLE) 5BQ7A Tungsol black plates NOS 1960 era (12.0/12.2ma) 1-2% section balance
(!) (Single) 5BK7A GE gray plates "U" getter NOS 1964 (7.5/10.5ma)
(!) (Single) 5BK7A GE gray plates "U" getter NOS 1973 (8.5/11ma)
(!) 5BQ7A RCA black plates NOS 1964 (11.6/14.4ma)
5BQ7A GE black plates "U" getter 1961 (10.8/7.0ma)
5BQ7A GE Dumont gray plates "O" getter 1973 (12.8/8.2ma)
5BQ7A RCA branded Raytheon black plates "D" getter faded printing 1950's (14.0/13.6ma)
6BK7B Philco by Sylvania NOS 1960 (13.2ma/15.2ma)
