Electro-Harmonix Micro Synthesizer XO Analog Guitar Microsynth 3-pole analog resonant filter 4 voice mixer section mixes: sub octave, original, octave up and square wave Start, stop filter frequency sliders with adjustable rate for full control over the filter's sweep direction and speed, Adjustable filter resonance control, Adjustable attack time control for fading-in notes True bypass, all analog design 96DC-200BI power supply included