Basic Audio Scarab DeluxeThis is a "Deluxe" version of the Scarab with more control over "feel" and adjustments in bias. This version adds in a couple knobs over the 3 knob version. BIAS: Tonebender type circuits vary depending on the bias of the 3rd transistor. Gritty gated tones on one end of the dial, sustaining lead tones in the middle and sweet lower gain tones at the other end of the rotation. Bias affects tone and gain. FAT: The low end at the input of the circuit