Eurorack Reference / modules /make-noise/spectraphon audit site v0.1 — milestone 3
make-noise/spectraphon

Spectraphon

Make Noise

The Make Noise/soundhack Spectraphon is a dual Spectral Oscillator coded by Tom Erbe of soundhack, the first module built by Make Noise on their new digital hardware platform engineered by Jeff Snyder and Tony Rolando. It uses real-time spectral analysis and resynthesis to create new sounds from those that already exist, inspired by spectral processors, additive synthesis, vocoders, and resonators including the Buchla 296 and Touché, in the lineage of the Buchla 259 and Make Noise DPO. Each of the two sides (A and B) operates independently in Spectral Amplitude Modulation (SAM) or Spectral Array Oscillation (SAO) mode.306

Capabilities 3

Envelope Followerenvelope-follower
Sub/CV output acts as an envelope follower in SAM mode, outputting a positive CV representing the current amplitude of the sound at the input.306
FM Oscillatorfm-oscillator
Internal FM bus allows high-definition frequency modulation between the two sides in both directions simultaneously, without cross-modulation or feedback, and without affecting the core frequency at the Sine and Sub outputs.306
Spectral Oscillatorspectral-oscillator
Dual spectral oscillator with two independent sides (A and B), each operating in SAM (spectral amplitude modulation from input) or SAO (oscillation from stored spectral arrays). First Make Noise module on new digital hardware platform engineered by Jeff Snyder and Tony Rolando with DSP by Tom Erbe (soundhack).306

Jacks 22 — 14 in / 8 out

NameSignalVoltageDescription
Inputs (14)
A 1v/octcv306
A Clock Inclock306
A FM Index CVcv306
A Focus CVcv306
A Partials CVcv306
A Slide CVcv306
A-In CVcv306
B 1v/octcv306
B Clock Inclock306
B FM Index CVcv306
B Focus CVcv306
B Partials CVcv306
B Slide CVcv306
B-In CVcv306
Outputs (8)
A Even OutaudioOutputs even harmonics of Side A's current spectrum. Normalled to Odd output. In SAO, can be offset in pitch by up to an octave using the A-In attenuator or modulated with an external signal.306
A Odd OutaudioOutputs the odd harmonics of Side A's current spectrum. When Even output is unpatched, both Odd and Even are summed here.306
A Sine OutaudioSine wave that always oscillates at the A side core frequency, unaffected by FM, Partials, or other modulations.306
A Sub/CV OutmixedIn SAM outputs an envelope follower; in SAO outputs a sub-sawtooth oscillator. Can also be set to Stepped Random CV, Smooth Random CV, Triangle LFO, or Ramp LFO via Shift+CV.306
B Even Outaudio306
B Odd Outaudio306
B Sine Outaudio306
B Sub/CV OutmixedIn SAM outputs an envelope follower; in SAO outputs a saturated sub-sine oscillator. Can also be set to Stepped Random CV, Smooth Random CV, Triangle LFO, or Ramp LFO.306

Parameters 16

NameTypeRangeBehavior
A FM IndexknobSets the depth of internal FM applied to Side A from Side B's core frequency. This FM is calculated internally at high resolution without altering the core frequency as represented at the Sine and Sub outputs.306
A-Inknob≤1octaveIn SAM: sets the input signal level (modulation depth) with tickmarks for typical modular and line level signals. In SAO: acts as a frequency offset/detune for the Even harmonics only, with a range of up to one octave when unpatched; accepts bipolar signals for pitch sequencing or secondary FM of Even harmonics.306
B FM IndexknobSets the depth of internal FM applied to Side B from Side A. Becomes an input attenuator when B FM Index CV Input is patched.306
B-Inknob≤1octaveIn SAM: sets the input signal level (modulation depth). In SAO: acts as a frequency offset/detune for the Even harmonics only, with a range of up to one octave when unpatched.306
Fine TuneknobFine tuning of the side's core frequency. Summed with Frequency and 1v/oct input.306
FocusknobMode-dependent. In SAM: sets width/sensitivity of harmonic bands — lower values give more pronounced individual harmonics, higher values let more harmonics ring longer. In SAO (linear mode): spectral compression (CW) or expansion (CCW). In SAO (planar mode): fine spectrum selection. In Noise mode: sets high-pass filter frequency for modulating noise. In Chaos mode: sets harmonic ratio of the paired sine oscillator.306
Focus Attenuverterknob306
Follow/Sync ButtonbuttonSelects Follow or Sync behavior for Side B. Button lights for FOLLOW (Side B pitch tracks Side A with B's Pitch as offset), flashes for SYNC (Follow + hard sync of B to A), OFF for neither. Also switches CV mode for Sub/CV output.306
FrequencyknobSets the core frequency of the side, summed with Fine Tune and 1v/oct. The sine wave output always oscillates at this core frequency.306
PartialsknobSets relative emphasis of harmonics at Odd/Even outputs. At fully CCW: silence. Increasing from CCW adds lower harmonics first, then middle and high harmonics, until fully CW where all harmonics play at full amplitude per the current spectrum. Odd and even harmonics are increased alternately as control is raised.306
Partials Attenuverterknob306
SAM/SAO/Array Button AbuttonSwitches Side A between SAM and SAO modes. Button lights to indicate SAO. When held with Shift-A in SAM, begins/ends Array creation. In sp52+, also accesses Noise and Chaos modes. Shift+Array in oscillator modes switches Side to low frequency.306
SAM/SAO/Array Button Bbutton306
Shift ButtonbuttonPress to manually clock the Spectraphon (same as Clock input). Hold to access Shift functions: Shift+ARRAY begins/ends Array creation in SAM (or switches to low frequency in oscillator modes in sp52+); Shift+CV selects Sub/CV output mode; Shift+Shift shifts the active Array. Also used as tap tempo for LFO rate when clock input is unused.306
SlideknobMode-dependent spectrum modulator. In SAM, selects the fundamental frequency (first harmonic) for spectral analysis. In SAO (linear mode), selects which spectrum is output across the full array range (fully CCW = first, fully CW = last). In SAO (planar mode), coarse selection through the array. In Noise mode, sets low-pass filter frequency for modulating noise.306
Slide Attenuverterknob306

Firmware history 3 versions

VersionReleasedNotes
sp671. Linear Array Modulation in SAO: Slide now selects spectra linearly; Focus provides spectral compression/expansion. Original Planar modulation still accessible via holding Shift 2 seconds in SAO. 2. New Ramp LFO shape on Sub/CV outputs. 3. CV output LFOs' minimum clock rate increased to 8 seconds.306
sp521. Two new oscillator modes: Noise and Chaos. 2. Low Frequency behavior added to SAO, Noise, and Chaos modes (Shift+Array to activate). 3. All Mode options reset to factory settings when powering on while holding SHIFT A & SHIFT B. 4. Improved low frequency compensation for Partials in SAO. 5. Minor bug fixes.306
sp381. Sub-Oscillator now available as Sub/CV output mode in SAM (previously SAO only). 2. Adds option to delete currently selected User Array and return to Default (hold Shift on deleting side, then hold opposing Shift for 2 seconds). 3. Fixes critical bug where calibration for panel controls and/or v/oct scaling could be accidentally erased. 4. Minor bug fixes.306

References 3

  1. [306]
    Make Noise / Soundhack Spectraphon Manualmanual
    verified 2026-05-11
  2. [307]
    Make Noise Spectraphon Zine (companion documentation)manual
    verified 2026-05-11
  3. [308]
    Make Noise Spectraphon product pageproduct_page
    ⚠ verified 2026-05-11 · manufacturer changed since last verified