(!!!!!) (Best Pair) 6550A GE NOS "stapled plates" 1985-1986 (138.8ma and 139.2ma) 1-2% matched

1 pair) 6550A GE NOS "stapled plates" 1985-1986 - large shiney getters on both tubes - excellent pair - sweet lush midrange 1 tube) 138.8ma and Gm=11,800 1 tube) 139.2ma and Gm=11,650   TUBES PLUGGED INTO OCTAL SOCKETS IN PHOTO   Good Ma range 120-140ma Good Gm range = 10,000 - 12,000   (warm and punchy midrange, good bass, a very good 6550 second only to Tungsol 6550 in overall sound and drastically superior to Svetlana or Sovtek 6550) - ARC VT60, ARC VT100 MarkII and MarkIII, Ref. 300, Ref. 600 - Audio Research Reference 3 line-stage power supply - Luxman- Rogue- Cary - VTL MB300, MB450, ST-150- CJ Premier 8 and 11A, 12- Jadis - Ampeg SVT- Comins Alessandro Jazz Guitar Amp - Cary SLI-80 - THD - VAC PA100/100- McIntosh 275 MK IV 2005- Harmon Kardon- Audio Aero Capitole Integrated amp