(!!!!!) (2nd Best Tungsol Pair) 6550 Tungsol USA branded GE gray plates with vent holes 1968 in white boxes (142.5ma and 148ma) (Highest Ma and Gm)
(!!!!!) (Best Black Plate Single) 6550 Tungsol black plate NOS 1960 (136ma) (Recommended for Audio Research and Tavish power supply)
(!!!!!) (Best JAN Pair) JAN-6550A GE NOS "stapled plates" 1984-1985 (123ma and 124ma)
(!!!!!) (BEST OVERALL QUAD) JAN-6550A GE NOS 1985-1986 (146ma, 146.5ma, 147.0ma, 147.6ma)
(!!!!!) (BEST OVERALL QUAD) JAN-6550A GE NOS 1985-1986 (147ma, 148ma, 148.6ma, 149.5ma)
(!!!!!) (BEST OVERALL QUAD) JAN-6550A GE NOS 1985-1986 (151.5ma, 151.5ma, 153ma, 153.2ma)
(!!!!!) (BEST OVERALL QUAD) JAN-6550A GE NOS 1985-1986 (151ma, 151.5ma, 151.8ma, 153.0ma)
(!!!!!) (Best Pair) 6550A GE NOS "stapled plates" 1985-1986 (137ma and 139.3ma)
(!!!!!) (Best Pair) 6550A GE NOS "stapled plates" 1985-1986 (153.3ma and 154.5ma) 1-2% matched
(!!!!!) (Best Pair) 6550A GE NOS "stapled plates" 1985-1986 (156.8ma and 158.2ma) 1-2% matched
(!!!!!) (BEST QUAD) JAN-6550A GE NOS 1985-1986 (129ma, 129ma, 129.5ma, 130ma) 1-3% matched
(!!!!!) (BEST QUAD) JAN-6550A GE NOS 1985-1986 (130.2ma, 131ma, 131.2ma, 132.6ma) 1-3% matched
(!!!!!) (BEST QUAD) JAN-6550A GE NOS 1985-1986 (132ma, 133.5ma, 134ma, 134.5ma) 1-3% matched
(!!!!!) (Best Single) 6550 Tungsol USA NOS branded GE gray smooth plate 1962 (133ma) (Recommended for Audio Research power supply)
(!!!!!) (Best Tungsol Pair) 6550 Tungsol USA branded GE gray plates with vent holes 1968-1969 in white boxes (135.5ma and 135.8ma) (close Ma and Gm)
(!!!!!) (Best Tungsol Single) 6550 Tungsol USA NOS branded Sylvania gray smooth plate 1960 era (142.5ma) (Audio Research, Tavish power supply)
(!!!!!) (Recommended Pair) 6550A GE NOS "stapled plates" 1985-1986 (147.4ma and 149ma)
(!!!!) (Good Value Single) 6550 Tungsol black plate used/good 1957 1st series made (117ma) (Recommended for Audio Research power supply)
(!!!!) (Recommended Tungsol Single) 6550 Tungsol black plate like new 1957 tarnished base (130ma) (Recommended for Audio Research power supply)
(!!!) (Best Value Single) 6550 Tungsol gray smooth plate 1960 low hours/like new (125ma) (Recommended for Audio Research power supply)
