This Pedal is currently available.
State Variable Filter
The Chromatron is the result of 10 years tweaking, refining and reimagining the state variable filter circuit. It is an optically-controlled analog filter that can switch between envelope control and manual control via expression pedal with the push of a button. The envelope detector is an original design, producing a musical filter response that spans a broad range of tones from vintage quack to future-synth psychedelica.