(!!!!!) (Best GE Pair) 6550A GE NOS "stapled plates" 1980-1982 (150ma and 152.5ma)
(!!!!!) (Best JAN Pair) JAN-6550A GE NOS "stapled plates" 1984-1985 (123ma and 124ma)
(!!!!!) (Best Overall Single) 6550 Tungsol black plate NOS branded Sylvania late 1950's (135ma) (Recommended for Audio Research power supply)
(!!!!!) (Recommended Pair) 6550 Tungsol branded Raytheon smooth gray plates NOS 1960-1963 era (126ma and 127ma)
(!!!!!) (Recommended Single) 6550 Tungsol black plate NOS 1960 (136ma) (Recommended for Audio Research and Tavish power supply)
(!!!!) (Best Tungsol Single) 6550 Tungsol USA NOS branded Sylvania gray smooth plate 1960 era (142.5ma) (Audio Research, Tavish 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)
(!!!) (BEST VALUE) 6550 Tungsol USA NOS gray smooth plate rebranded RCA 1962 (123ma) (Recommended for Audio Research Ref power supply)
(!!) (BEST VALUE) 6550A GE stapled plates NOS around 1980 (119ma) (nice single)
(!!) (Recommended Single) 6550A GE stapled plates NOS 1979 (136.5ma)
(!!) (Recommended Single) 6550A GE stapled plates NOS 1980's (147ma)
6550 Sylvania branded RCA used/good 1979 (112ma)
6550 Tungsol branded RCA gray plate with vent holes used/good 1970 (121ma)
6550 Tungsol branded RCA gray plate with vent holes used/very good 1970 (129ma) (High Gm)
6550A GE stapled plates used/good 1980's (115ma)
