307A=VT-225 Ken Rad NOS/75% coated glass 1940”s (34ma)

307A=VT-225 Ken Rad NOS/75% coated glass 1940”s

34ma 75%

Gm=3100 75%

Good Ma range 45=50ma

Gm Gm = 4000

(307A=VT-225 Sylvania / Ken-Rad, Identical to Western Electric, 6 Watt Pentode)
(The 307A is a 306A with a quick heating filament, 5.5V @ 1A filament,
5-pin bayonet socket with top cap)

– Peter Millett headphone amp

– Eddie Current Balancing Act