THD ELECTRONICS BIVALVE 30 HEAD (BIV30)
- 30W, head-unit only, class A four tube chassis, preamp: 2 X 12AX7 (or optional 12AT7, 12AU7, 12AY7, 12AZ7), power: 2 X 6L6 (or optional EL34, 6550, KT66, KT77, KT88, KT90), single channel, front chrome control panel, five knobs (v, t, b,...