(!!) (Pair) 6S4A GE NOS 1969-1970 (24.0ma and 25.5ma)

1 pair) 6S4A GE NOS

1 tube) 25.5ma Gm=4700 (1970) (MC)
1 tube) 24.0ma Gm=4400 (1969) (FZ)

Matched on Amplitrex

Vplate=250V

Vgrid=-8V

Good Ma range 20-25ma

Good Gm range 4000-4500

(the 6S4A features high plate current at relatively low plate voltages and is capable
of withstanding high pulse voltages)(Vfil=6.3V @ 600ma)

MAX Ratings: Vplate=550V, Iplate=30ma, Pout=8.5 watts

Typical Operation:

Vplate=250V, Vgrid=-8V, Iplate=24ma, Mu=16.5, Gm=4500, Rplate=3700 ohms

- Woo Audio GES Electrostatic headphone amp