Septitone is a quantizer that supports heptatonic scales, or scales with 7 tones, with each scale degree (root, 2nd, 3rd etc.) capable of being independently added or removed from quantization. Scale degrees can be enabled using either performance buttons or gate signals. This allows the creative applications such as...

  • Adding variety over time by altering allowed scale degrees
  • Constraining quantization to just chord tones
  • Creative harmony by constraining degrees to specific voices
  • Creating pentatonic (5 tone) scales from existing heptatonic (7 tone) scales
  • Just having a lot of fun and jamming

Intro & Manual Video:

Septitone includes other features, like...

Additional Features

Dual Hold Modes

Quantization can sometimes get in the way of expression, stopping pitch glides, vibrato, or other similar expressive pitch techniques. Septitone comes equipped with two hold modes to allow a high degree of control over when quantization happens.

Up: With the hold toggle set to the UP position (default), Septitone behaves like a typical quantizer. When a leading edge (high gate) is detected on the GATE input, the value at IN will be quantized with the result being set on the OUT port and remaining in the quantized state until the next gate pulse. This mode can be thought of as a bit like a sample-and-hold feature, where the quantized output is sampled then held until the next gate high is received. This mode works just as well with either triggers or gates.

Down: With the hold toggle set in the DOWN position, Septitone will only quantize the output when the signal at GATE is high. Each time the input at GATE goes high, the pitch at IN will be quantized and the scale degrees evaluated. However, when the input at GATE goes low, the raw CV at IN will be passed through unmodified. In this way, clever use of gate delay or envelope at the GATE input can allow glides or vibratoes through. This mode can also be used for all kinds of crazy effects.

Roots: Modulatable Circle of Fifths

The order of roots is laid out to match the circle of fifths. Neighboring roots share the most in common. For example, the starting root is C, which contains no sharps or flats. One root to the left is F, containing only one flat, and one root to the right is G, containing only one sharp. This means that modulating the root results in much more musical-sounding modulation.

Performance Freeze

To add a bit of performance control and creative expression by the modular artist, the button on the far right under the "out" section fo the LCD allows the quantizer to be frozen. While frozen, the quantizer will hold the current output, regardless of gate or HOLD mode states. The current output will be held even if it is not a quantized value.

Included Scales

  • Major (Ionian)
  • Natural Minor (Aeolian)
  • Melodic Minor
  • Harmonic Minor
  • Dorian Mode
  • Locrian Mode
  • Lydian Mode
  • Mixolydian Mode
  • Phrygian Mode
  • Harmonic Major
  • Double Harmonic (Byzantine / Arabic)
  • Acoustic
  • Altered
  • Neapolitan Major
  • Neapolitan Minor
  • Persian

Manual & Tutorial


  1. Left/Right Root Buttons - This moves current root backwards or forwards along the circle of fifths
  2. Left/Right Scale Button - This moves the current scale backwards or forwards.
  3. Freeze - Holds the quantized output at the moment the button was pressed, regardless of gates or the state of the hold switch. Resumes normal behavior once toggled off. This can allow interesting performance control.
  4. HOLD - Changes the hold mode behavior between hold and gate (see above)
  5. Root-7th Buttons - These buttons toggle on or off if the given scale degree is allowed to be assigned during quantiation. An unlit button will not allow the degree, while a lit button will
  6. Root-7th Button (Double Click) - Degree buttons can also be double clicked to change their mode to invert mode. In Invert mode, the scale degree is included when the gate is low, and excluded when the gate is high.
  7. Invert Button - Inverts the allowed degrees selection. For example, if only Root is toggled on, activating invert will allow 2nd, 3rd, 4th, 5th, 6th and 7th degrees to be quantized, but not the root.


  1. IN - The base pitch CV in which to quantize.
  2. GATE - Quantization happens when a gate signal is received at this jack. How the gate/trigger signal modifies the output is dependent based on the state of the HOLD switch (see below).
  3. ROOT - Modulate the root note using CV. Root follows the same standard as 1v/oct, so +1v will modulate the root not
  4. Root-7th, Invert Gate - Allows a gate signal to modify the state of the degree or invert toggle. When a cable is connected to the gate jack, the actual toggle state will be modified, and will remain in the modified state once the cable is disconnected


  1. OUT - The quantized pitch output or the value currently at the IN jack depending on hold mode and gate

Patch Ideas

Lead-in Glide (Envelope Over Gate)

Septitone considers the gate "high" if it exceeds 4v. An AR, AHR, or ADSR envelope can be used to delay quantization to allow initial glide through. Take the gate signal that would have been given to Septitone, but pass it through an evenlope instead. Longer attack becomes a longer delay before quantization happens.

Exclude Root

In electronic music, it's common for the bass line to play only the root note on an interesting rhythm. In these instances, it can add some sonic intersting to have other voices in the patch not playing the root note, thereby creating harmony. Patch the gate signal of the bass line to the root, setting the root degree button to invert mode (double click). Each time the bass line hits, the other voices will not be allowed to play the root. To create additional contrast, also remove the 2nd and 7th voices.

Sequenced Chordal Quanitization

Using a multi-trigger sequencer, such as Misfit Audio's Drum Trigger Sequencer, connect multiple trigger channels to the scale degrees. Through clever placement of sequenced triggers, it can be possible to change the quantization settings to only allow tones of a certain chord. For example, feeding the Drum Trigger Sequencer a 2 whole note clock, the first step could enable the root, 3rd, and 5th scale degrees (tonic), while the second step could enable the 4th, 6th, and root (subdominant) degrees, and finally the 3rd step could enable the 5th, 7th, and 2nd (dominant) degrees.

Analog-to-Digital Conversion

Septitone degree gates and invert are exactly 8 gates, so they pair well with an analog-to-digital (ADC) module. Try patching all 8 outputs of an 8-bit ADC module to control Septitone and see what the results are.

Change Log

May 1, 2022 - build 15

  • Removed a small amount of slew that was occuring on the quantized CV. This should eliminate extra notes when converting quantized pitch to MIDI.

September 16, 2021

  • Improved module response to specific input cases around negative voltages and exact pitch values
  • Improved module handling of root modulation
  • Septitone is now rated for input voltages -5.0v to 8.0v
  • LCD now updates at a regular cadence independent of input gate
  • Thanks to R_ for all the input and testing on this build

August 24, 2021

  • Fixed a bug where scale degree gates were being assigned to the wrong degree

July 19, 2021

  • Fixed a bug where scales with a root of F were incorrectly wrapping back around to the wrong degree or octave

February 13, 2021

  • Module is now bypassable
  • Hold mode will now always be enabled when randomizing
  • Improved the behavior of channel inversion to be slightly more intuitive
  • Fixed a rare bug that tried to select a non-existent scale when randomizing

Jan 19, 2021

  • Initial release