POLE-ZERO is a 4-pole (24dB/octave) low pass Voltage Controlled Filter (VCF) utilizing MOSFET transistors. MOSFETs are known for their soft, vacuum tube like distortion when overdriven.

POLE-ZERO is designed to exploit these characteristics with the addition of a MOSFET saturation control and provide a much wider palette of sounds when compared to a standard VCF.

A Voltage Controlled Amplifier (VCA) is also a relatively novel addition and provides a simple way to amplitude modulate the filter without the need of an external VCA.