Genus: the number of poles. A traditional ladder filter has a fixed pole count that sets its rolloff slope. EVOLUTION's Genus control places that under continuous voltage control, sweeping from 3 to 6 poles, an effective cutoff slope from 18 dB/oct to 36 dB/oct. LEDs give continuous indication of the current slope, so you can hear and see the filter change character in real time.

Species: drive and distortion. The Species control varies the signal level into the ladder, letting you control the intensity of the filter's characteristic distortion. In self-oscillation mode it instead modulates the amplitude of EVOLUTION's output.

Resonance and frequency. Resonance is voltage-controlled, with a Q Level Compensation control that balances the resonant peak against the frequencies below cutoff that would otherwise be attenuated as resonance is increased. An extremely accurate, temperature-stable exponential frequency generator (accurate over 10 octaves) rivals the specifications of the best analog VCOs.