NOS 6BL8/ECF80

Assorted NOS 6BL8/ECF80 9-pin medium mu triode, sharp cutoff pentode. Used in many HH Scott designs including the following:
299-A
333-A
333-B
335
340-A
350-A
350-B
350-C
350-D
355
380
4310
LM-35
LT-110-A
LT-110-B