Make Noise tELHARMONIC
Three-algorithm additive, noise, and phase mod harmony engine
14 HP Eurorack module
The tELHARMONIC is a multi-voice, multi-algorithm synthesizer module coded by Tom Erbe (Soundhack) offering three simultaneously available tone generation algorithms: Additive Harmonic synthesis (inspired by Thaddeus Cahill's Telharmonium), Noise synthesis (inspired by James Tenney's 1961 'Analog 1: Noise Study'), and Phase Modulation synthesis (inspired by 1980s commercial digital synthesis). Its left side provides voltage-controlled music theory — Tonic, Interval, Degree, and D-Gate — enabling patch-programmed chord progressions, scales, and melodies without manual performance or MIDI, while the right side sculpts timbre via Centroid, Flux, and H-Lock across all three simultaneously available audio outputs.
Features
- Three simultaneously available audio outputs: Noise (N), Harmonic (H), and Phase Modulation (P)
- 24-partial harmonic oscillator with H-Lock for additive synthesis preset building
- Voltage-controlled music theory: quantized Degree, Interval voice spacing, Tonic transposition
- D-Gate Track and Hold for Degree enables extracting melodies from non-melodic CV sources
- Gate Output fires on every Degree change for synchronized envelope triggering
- Meantone temperament for triad voicings with 1V/oct equal temperament transposition via Tonic
- H-Lock button and CV input for locking individual harmonics at full amplitude
- FM Input for linear frequency modulation of all three algorithms simultaneously
- Color Sta visual indicator showing Interval and Degree state while pulsing at Tonic frequency
- Hidden Spiratone mode: Shepard Tone generator accessed by holding H-Lock 5 seconds
- Hidden 3-Voice Shift Register mode accessed by holding H-Lock 2 seconds
- Phase Modulation Flux response is inverse to N and H Outputs
Controls & Jacks (27)
- P Output — Three-voice phase modulation algorithm; 10Vpp
- Interval — Sets pitch spacing of three Harmonic and Phase Mod voices; triads with inversions, fifths, unison, octaves, and continuous in-between tuning
- Interval CV Input — Voice spacing control; 0-5V range
- Flux — Unipolar combo knob; with no CV patched acts as panel control; controls timbre differently per algorithm: N focuses noise around fundamental
- Tonic — Panel control for main pitch across 6 octaves; sets base frequency for Interval and Degree
- Centroid — Modulates or selects harmonics for H Output; sets phase modulation ratio for P Output; has no effect on N Output
- Degree CV Attenuator — Bi-polar attenuator for Degree CV Input
- Centroid CV Attenuator — Bi-polar attenuator for Centroid CV Input
- N Output — Single-voice noise algorithm; 8Vpp
- FM Input — Linear frequency modulation for all algorithms; AC-coupled
- H Output — Three-voice harmonic algorithm; 10Vpp
- Centroid CV Input — Harmonic selection or phase mod ratio control; 0-8V range
- Tonic CV Input — 1V/octave pitch control; 0-6V range
- Degree CV Input — Quantized note selection; +/- 2V range
- Flux CV Input — Timbre modulation control; 0-8V range
- D-Gate Input — Track and hold gate for Degree; normalled high
- Gate Output — 10V gate signal at each Degree change
- H-Lock Input — Gate input to lock harmonics on
- Gate — Visual indication of activity at Gate Output
- H-Lock LED — LED brightness indicates number of harmonics locked on
- Interval CV Attenuverter — Bi-polar attenuator for Interval CV Input
- Degree 2 — Quantized note selection relative to Tonic pitch; 7 possible values per octave for triads, 12 for other intervals; determines chord sonority
- Degree 1 — Bi-polar attenuator for Interval CV Input
- Color Staff — Visual indicator that changes color to display state of Interval and Degree while pulsing to show Tonic frequency; for entertainment purpose
- Degree CV Attenuverter — Bi-polar attenuator for Degree CV Input
- Centroid CV Attenuverter — Bi-polar attenuator for Centroid CV Input
- H-Lock — With Flux above 10%, locks selected harmonic at full amplitude; [HOLD] 1 second to clear all locked harmonics; [HOLD] 5 seconds to find Spir
How-To Guides
- Drone with Sequential Harmonics
- Additive Presets via Sequenced H-Lock
- Diatonic Chord Progression
- Parallel Techno Chords
- Ascending and Descending Run
- Solar Wind Chimes
- Intelligent Bass with Phase Modulation
- Colored Noise Texture Sculpting
- 3-Voice Shift Register Chord Builder
- Artificial Deceleration with Spiratone
- Vibrato and Pitch Bend via FM Input
Explore the interactive tELHARMONIC panel on BleepDex — tap any control to learn what it does.
