(!) (Single) 37 Philco by Sylvania smooth plate tests like new 1940”s (8.3ma)

37 Philco by Sylvania smooth plate tests like new 1940”s in white box

8.3ma

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)