(!) (Best Single) 37 GE ribbed plate NOS 1943 (8.0ma)

37 GE ribbed plate NOS 1943

8.0ma

Gm=1100

Test parameters:

Vplate=250V

Vgrid=-18V

Iplate good range 6.5-8ma

Gm=1000-1100

(Filament=6.3V @ 300ma, many think the 37 sounds better than the 76)