Teia Synthesizers - OpticShifter

The OpticShifter is a 20-stage optical phaser from Teia Synthesizers, built around a chain of all-pass filter stages selectable from 4 to 20. An interesting detail here is that there's also a second switch that lets you choose which stage the feedback taps from, independently of the main output. So the number of phasing stages and the resonance point don't have to match — 20 stages of phasing with feedback pulled from stage 8, for instance, or any other combination — that decoupling opens up a much wider tonal range than a typical phaser design. Feedback polarity and magnitude are switchable too, and the feedback amount has its own CV input.

An internal triangle LFO handles phase modulation out of the box, with a CV-controllable rate and a dedicated output for use elsewhere. Before the signal hits the phaser stages, a tilt EQ (Tone) and an input level knob with clipping LED let you shape what goes in. Naturally, there's a dry/wet knob to accompany all of this.

Four outputs cover different angles: the main phased signal, a separate feedback path output — together usable as a pseudo-stereo pair — a wet-only output, and the Shred output. Shred runs the wet signal through an op-amp comparator, folding the phaser's movement into something harsh and square-edged; think more in terms of "texture weapon". A ping input lets you excite the all-pass chain with triggers or clocks, turning the phaser into a percussive voice — bell-like tones and metallic hits shaped by the current stage and feedback settings.

OpticShifter handles classic phaser duties without complaint, but has enough extras under the hood to wander into more abstract resonant lands, pseudo-stereo processing, and pinged percussion.

Features:

• 20-stage optical phaser with selectable stage count (4, 6, 8, 12, 16, 18, 20)
• Independent feedback origin stage selection
• Feedback knob with CV input and attenuverter
• Feedback polarity and magnitude switches
• Phase offset knob with CV input and attenuverter
• Internal triangle LFO with CV-controllable rate and dedicated output
• Hyper triangle waveshaper on phase CV path
• Pre-phaser tilt EQ (Tone)
• Input level control with clipping LED
• Dry/wet mix knob
• Main output (pseudo-stereo L) and feedback path output (pseudo-stereo R)
• Wet-only output
• Shred output (comparator-based distortion)
• Ping input for percussive excitation