(!!!) (Recommended GE Pair) 12SL7GT RCA black plates NOS 1974 (2.1/2.2ma and 2.3/2.4ma) (same Gm)
(!!) (Best Pair) 12SL7GT GE NOS 1969 (2.4/2.6ma and 2.6/2.7ma)
12SL7GT GE branded RCA NOS 1970's (2.2/2.4ma)
12SL7GT GE NOS 1966 (2.0/2.3ma)
