Here’s more info about the pedal directly from the manufacturer’s site:
The PHASER is based on the classic 4 stage Script circuit and the PH1-r, with a few additions for a more versatile pedal.
Like the Phase 90, the Phaser comes standard with a Rate control, but the similarities end there. The Phaser takes a page from the PH-1r playbook and adds Depth and Resonance, two controls that are imperative to exceptional phase tone. And what a tone it is—between these three controls, and especially the Resonance knob—a variety of phase tones are possible, from subtle warble through molten, volatile sweeps.
