Utilities

Quantizer

Pitch quantizer - snap any control voltage to the nearest note in a chosen scale.

What is a Quantizer?

A pitch quantizer snaps an arbitrary control voltage to the nearest valid musical note. Feed it a smooth voltage somewhere between 0V and 1V, and it rounds to the closest semitone, sending out a clean step like 4/12V or 7/12V instead of the messy in-between value. Patch a quantizer between any wobbly CV source and a VCO and the wobbles become a melody.

The math is simple. Modular synths use the 1V/Oct standard - an octave is exactly one volt, twelve semitones per octave, so each semitone is 1/12V ≈ 83.3mV. Quantizing means dividing the input voltage by 1/12, rounding to the nearest integer, and multiplying back. If the result lands on a note that isn't part of your selected scale - say a C# in a C major patch - the quantizer searches outward for the closest enabled note, biased symmetrically. The output is always musical, regardless of how chaotic the input is.

Quantizers turn random modulation into random melody. They turn LFO sweeps into arpeggios. They turn S&H voltages into musical pitches. They are the bridge between the world of continuous voltages, where modulars naturally live, and the world of equal temperament, where most Western music expects to live. Without a quantizer, a random source drives a VCO into microtonal swirl; with one, it drives the same VCO around the notes of a pentatonic minor.

Most quantizers offer a library of scale presets - chromatic, major, minor, pentatonic, blues, the modes, and more exotic options like whole tone or harmonic minor. Better ones expose per-note enables so you can build any custom scale: turn off the third for an open, suspended sound; enable only the root and fifth for power-chord drones; design a microtonal seven-of-twelve scale of your own. A root parameter rotates the scale up to a different starting note; a transpose parameter shifts the entire output up or down without changing the scale's intervals.

Our Quantizer

Our Quantizer is dual-channel - two complete pitch quantizers in one panel - so you can run a bass line and a lead line from the same patch with shared scale, root, and transpose settings, but independent inputs and triggers. This matters more than it sounds: the two voices stay locked to the same key automatically, no matter how the root CV moves.

Thirteen scale presets ship out of the box (chromatic, major, minor, both pentatonics, blues, four church modes, harmonic minor, whole tone, diminished). On top of that, twelve per-note enables let you override any preset to build a custom scale by hand - turn off the third of major, leave only root and fifth for power-chord drones, design your own seven-note mode. The root knob rotates the scale; an additional root CV input modulates it in performance, so a slow LFO can drift the patch through different keys over a song.

Each channel has a trigger input for sample-and-hold quantization (so the pitch only updates on a clock edge, no mid-note glitches) and a gate output that pulses on every note change - patch it to an envelope and you get articulation that follows the melody. The glide knob smooths the transition between notes for portamento. The seven-segment display reads out the current note name and octave so you can see what's playing without listening.

In a patch

The classic generative patch: Noise -> S&H (clocked) -> Quantizer -> VCO V/Oct. The S&H turns continuous noise into stepped random voltages; the quantizer locks those voltages to a scale; the VCO sings them as pitches. Patch the quantizer's gate output into an ADSR and the envelope re-triggers only when the pitch changes - musical phrasing emerges out of pure randomness.

Quantizers also tame imprecise CV sources. A long LFO ramp sweeping a VCO drifts microtonally; the same ramp through a quantizer becomes a chromatic ladder you can hear distinct steps in. A handwritten function generator curve becomes a melodic phrase. A step sequencer whose knobs are slightly out of tune becomes perfectly in tune.

Live key changes are easy. Patch a slow LFO or a stepped random source into the ROOT CV input and the entire scale rotates over time - the patch plays in C major for a while, then in A minor, then in F major, without changing any other voltage in the system. With transpose CV, you can move the whole melody up or down an octave on cue from another sequencer.

Inputs

IN 1 (cv) — Channel 1 CV input. The voltage to quantize. Typically from a random source, sequencer, or LFO.
IN 2 (cv) — Channel 2 CV input. Independent second channel. Same scale and root as Channel 1.
TRIG 1 (gate) — Channel 1 trigger. When patched, quantization only happens on trigger rising edges (sample-and-hold mode). When unpatched, quantizes continuously.
TRIG 2 (gate) — Channel 2 trigger. Same behavior as TRIG 1 but for Channel 2.
ROOT (cv) — Root note CV. Modulates the root note of the scale. Use for live key changes - 1V = 1 semitone shift.
TRNS (cv) — Transpose CV. Shifts the output pitch up or down. Applied after quantization.

Outputs

OUT 1 (cv) — Channel 1 quantized CV output. Clean V/Oct pitch locked to the selected scale.
OUT 2 (cv) — Channel 2 quantized CV output.
GATE 1 (gate) — Channel 1 gate. Fires a pulse whenever the quantized note changes. Perfect for triggering an ADSR.
GATE 2 (gate) — Channel 2 gate. Same behavior for Channel 2.

Controls

Root — Root note of the scale (0-11: C, C#, D, D#, E, F, F#, G, G#, A, A#, B). All notes in the scale are relative to this root.
Scale — Scale preset: Chromatic, Major, Minor, Pentatonic Major, Pentatonic Minor, Blues, Dorian, Mixolydian, Lydian, Phrygian, Harmonic Minor, Whole Tone, Diminished. Selecting a preset updates the note toggles.
Glide — Portamento between notes (0 to 1). At 0, pitch changes instantly. Higher values slide smoothly between notes for expressive legato.

Inspired by

A standard dual pitch quantizer with the usual repertoire: 13 scale presets, per-note gating for custom scales, root and transpose CV, glide for portamento between quantized notes, and trigger inputs for sample-and-hold quantization.

Doepfer A-156
Intellijel Scales
classic chromatic and scale quantizer

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