AC30 History

The original VOX AC30/4 from 1960 was in a sense the beaved up version of the AC4/AC6/AC10/AC15 line. The first AC30 is considered as the “best sounding AC30”, but… the EF86 pentode know for microphonic behaviour and the massive volume of the AC30 is simple too much for the EF86 (actually: it is not recommended to put a EF86 into a combo, although it is possible for a small combo like the AC4).

The vox showroom give some insides in the original circuit used. At the VOX KORG site, only the circuit diagram is available with a “regular” 12AX7 preamp tubes.

The AC-30 is a Push-Pull Power Output Stage amplifier, using for EL84 pentode tubes and a 12AX7 phase invertor.