Tonic - Interval Generator

Rebel Technology

Tonic is an additive interval pitch sequencer that turns triggers into melodies.

Tonic is a clever but uncomplicated module which opens up new possibilities in a modular system. It’s a new concept and very different from a step sequencer, allowing a new way of thinking about musical sequences and melodies.

In a slim 6HP format it offers one adjustable and five fixed intervals. Each interval has a trigger input and manual trigger button. Freely combine intervals for more than four octaves chromatic range.


Tonic works by adding intervals when triggered. From top to bottom, the intervals are:

    • Adjustable -6 to +12 semitones

    • +16 semitones

    • +8 semitones

    • +4 semitones

    • +2 semitones

    • -1 semitone

The bottom interval is negative, the middle four are positive. The top, adjustable interval has a range from minus one half octave at fully counter-clockwise, to plus one octave at fully clockwise, with zero in the middle.

The default tuning gives you wholetone steps: +2, +4, +8 and +16 semitones. The bottom, negative interval drops the pitch by a semitone. By adding them up this provides a basic range of 32 semitones, not counting the adjustable interval.

Custom Tunings

Tonic is entirely analog, and the fixed intervals can be tuned with the five 23-turn precision trimpots on the back of the module.

The tunable range for each interval is, from top to bottom:

    • 0V to 2.15V

    • 0V to 2.15V

    • 0V to 1.55V

    • 0V to 1.55V

    • -1.55V to 0V

1V equals one octave by Eurorack convention. Tonic can just as easily be tuned to Equal Temperament, Just Intonation, Meantone, or microtonally.


+12v: < 85mA
-12v: < 15mA
Depth: 25mm