The V3320 is a high performance voltage controlled four-pole filter with voltage controllable resonance. A wide variety of filter responses, such as low pass, high pass, band pass and all pass can be achieved by connecting the four independent sections. A single input exponentially controls the frequency over greater than a ten octave range with little control voltage feed-through. Another input controls the resonance from zero to low distortion oscillation in a manner of modified linearity.Every filter section includes a novel variable gain cell and a buffer. The variable gain cell features a better signal-to-noise ratio and low distortion.