(!!) (Recommended Pair) 6GK5=6FQ5A GE NOS 1968-1981 (10.4ma and 11.2ma)

1 pair) 6GK5=6FQ5A GE NOS same build

1 tube) 10.4ma Gm=14,100 (1981) (HS)

1 tube) 11.2ma Gm=14,600 (1968) GE branded Admiral

Tested on Amplitrex

Good Ma range 9-11ma

Good Gm range 13,00-15,000

– Conrad Johnson Premier 10, 14 preamp and DAC
– Supratek
– Wright