By turning the gain control knob you can add pure, flat-EQ gain, ranging from 6dB to 25dB! The Resonance Switch drops the resonant peak of a single coil pickup up to 5KHz, making a single coil sound like a full and fat humbucker. Features fully discrete Class A circuitry along with true bypass. Comes in a heavy-duty steel chassis and runs on a single 9 volt battery.