(!!!!) (Recommended Pair) 6SN7GTB Sylvania chrome top gray plates 1950's used/very good (9.6/9.0ma and 8.6/8.2ma) (Gm like new)
(!!) (Best Single) 13EM7 RCA coin-base black plates NOS 1970's (2.7/47.2ma)
(!!) (BEST SINGLE) 13EM7 Sylvania NOS 1960 era (1.4/56ma)
(!!) 13EM7 RCA black base black plates NOS 1968 (2.0ma/28ma)
13EM7 GE branded ITT NOS 1960's (2.2/38ma)
13EM7 GE branded Raytheon NOS 1960's (1.6/40ma)
13EM7 Sylvania branded GE NOS 1963 (1.5/34ma)
13EM7 Westinghouse Canada NOS same build as RCA 1970 (1.3/38ma)
