This is a clone module of the Polivoks filter, which has a very attractive unique rough and fat sound quality. With 2 pole (12db / Oct) characteristics, the resonance is controlled by a knob, and when turned to the right, unstable self-oscillation occurs. There are bandpass and lowpass outputs. There are two FM inputs that modulate the cutoff frequency with CV, with and without attenuator, and two signal inputs with gain control.mixI can do it.