The Twin Face is a versatile pedal that allows you to toggle between NPN and PNP modes with a switch. It combines the soft attack and warmth of Germanium PNP with the harder edges and sustain of Silicon NPN. The pedal has independent bias controls for each pair, allowing you to blend the two modes together.

To bias the Twin Face, you need to set your DMM to read DC voltages and place the black probe in the screw hole of your enclosure for ground. Then, place the red probe on the collector of Q2 and adjust the trimmer until you reach roughly 4.5V on the NPN side and -4.5V on the PNP side.

The Twin Face also features an onboard voltage inverter, which allows NPN or PNP operation from a standard center-negative 9VDC power supply. This eliminates the need for multiple power supplies or grounding issues when using the pedal in a daisy-chain setup.

The controls on the Twin Face include a Fuzz knob, which adjusts the amount of fuzz, and a Volume knob, which controls the output volume. There is also a toggle switch that allows you to switch between NPN and PNP transistors.

Summary created by AI from the original source.