1 matched quad) JAN-6550A GE NOS original boxes 1980's 1-2% matched

1 tube) 129ma Gm=11,400

1 tube) 130ma Gm=11,500

1 tube) 131ma Gm=11,200

1 tube) 129.5ma Gm=10.900

Matched on Amplitrex 

Good NOS Ma range 120-140ma

Good NOS Gm range = 10,000 - 11,000

(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