Zzzorb is a four-pole multimode filter plus a linear VCA!
Zzzorb's filter core comprises a cascade of four VCA-based integrators with a feedback path for resonance control. The integrators are mixed together in different combinations to provide five simultaneous filter outputs:
- Two-pole lowpass
- Four-pole lowpass
Zzzorb's built-in VCA is a handy way to apply a volume envelope or tremolo to your filtered signal. You can even use it as a feedback or self-modulation control by passing one of the filter outputs through it!
Zzzorb provides CV inputs and attenuverters for controlling the VCA level, filter resonance, and filter frequency. Additionally, it has a filter pitch CV input with a unipolar attenuator. When the attenuator is turned fully clockwise, the filter frequency tracks the pitch CV input at one volt per octave.
The output of Zzzorb's VCA is normally added to its filter input, providing a quick way to manually or electrically control your signal's level. You can break that connection and detach the VCA from the filter by connecting a patch cable to the VCA output.
The VCA's CV input is normally connected to the filter's frequency CV input so you can easily modulate the filter cutoff and the VCA level with the same signal. You can break that connection by connecting a patch cable to the VCA CV input.