Andreas' AC30 Special Head

Andreas’s AC30 Special Head

This was designed as a single input, dual channel amplifier, switchable between a Top-Boost style channel with three-way EQ stack and a BM ‘Normal’ style channel. The Top-Booster channel was routed via a Master Volume on a full-time basis, whereas the BM channel could be routed via the MV at the pull of its channel volume knob.

The master Volume control, also a pull-pot, switched the output valves between ‘Modern’ and ‘Vintage’ bias modes.

The amplifier also featured a switchable FX Loop that could be configured for either +4dBu or -10dBv signal levels.

Channel selection, audio ‘Mute’ and FX Loop enable switching was achieved both from the top panel, or a bespoke footswitch unit that plugged into the back of the amp and included full LED status Feedback.

A multi-tapped output transformer was developed that allowed the speaker outputs to be matched to 4, 8 or 16 Ohm cabs.

The amplifier’s chassis was designed and built from the bottom-up and topped with am Alu-printed aluminium facia panel, before being installed in a vintage VOX AC30 head cabinet.