Nitrous is a model of the TB-303 filter. The TB-303 filter is a diode ladder consisting of four poles, but providing an effective attenuation of 18dB per octave.
Control Description
Main controls
Cutoff: sets the frequency where the attenuation starts taking effect
Drive: controls the level of the input signal.
Resonance: controls the feedback of the circuit.
CV control
There are two inputs and attenuations that can be used to control the Cutoff control: CV1 and CV2.