Sofia

Xaoc Devices 24HP
fw 1955/1.1
OSCILLATOR VCO WAVESHAPER RESONATOR

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Analog formant oscillator implementing extended FOF synthesis. Triangle core plus two decaying-sine ripple elements (A, B) produce phase-coherent vocal/organic tones without filters. Per-element ratio, damp, warp, shape, and tracking give wide spectral control.

Patch Ideas · 9

★ Vocal vowel — fixed formants, played keyboard
SHAPE A/B = SINE · RATIO TRACK A/B = OFF (fixed formants) · RATIO A ~3 (F1), RATIO B ~6 (F2) · DAMP sliders mid · FUND·ELEM MIX mid · V/Oct from keyboard
▸ Show diagram
Patch diagramPatch diagram with 5 modules and 4 connections. Modules: Sofia, Keyboard, Env, VCA, Output. Signals: 2 audio, 1 cv, 1 pitch.SofiaKeyboardEnvVCAOutputOCTAVE: 4'RATIO A: 3RATIO B: 6RATIO TRACK A: OFFRATIO TRACK B: OFFSHAPE A: SINESHAPE B: SINEPITCH CV V/OCT1v/octMAIN OUTaudioCV1v/octOutcvCVcvInaudioOutaudioInaudioaudiocvpitch
★ Morphing vowel sequence
Two S&H from clocked random → RATIO A CV and RATIO B CV · attenuators ~5 · fixed formant tracking · creates stepped vowel shifts per note
▸ Show diagram
Patch diagramPatch diagram with 7 modules and 8 connections. Signals: 1 audio, 4 cv, 1 pitch, 2 clock.SofiaSeqClockS&H1S&H2NoiseOutputRATIO TRACK A: OFFRATIO TRACK B: OFFDAMP A: 50DAMP B: 60PITCH CV V/OCT1v/octRATIO AcvRATIO BcvMAIN OUTaudioPitch1v/octOutclkTrigclkIncvOutcvTrigclkIncvOutcvOutcvInaudioaudiocvpitchclock
★ Plucked string via warp and damp
SHAPE A = SQUARE · DAMP A low (short ring) · WARP A full CW (front-loaded density) · RATIO A tracks on · envelope into DAMP A CV extends ring
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: Sofia, Seq, Env, Output. Signals: 1 audio, 1 cv, 1 pitch.SofiaSeqEnvOutputSHAPE A: SQUAREDAMP A: 20WARP A: full CWRATIO TRACK A: ONFUND·ELEM MIX: 8PITCH CV V/OCT1v/octDAMP AcvMAIN OUTaudioPitch1v/octOutcvInaudioaudiocvpitch
Self-FM beast — IMPULSE into WARP
IMPULSE A → WARP B · IMPULSE B → RATIO A · creates recursive internal modulation, producing growling, animal-like dynamics that respond to pitch
▸ Show diagram
Patch diagramPatch diagram with 3 modules and 4 connections. Modules: Sofia, Kbd, Output. Signals: 1 audio, 2 cv, 1 pitch.SofiaKbdOutputRATIO A: 4RATIO B: 7DAMP A: 40DAMP B: 60PITCH CV V/OCT1v/octWARP BcvRATIO AcvIMPULSE A OUTcvIMPULSE B OUTcvMAIN OUTaudioPitch1v/octInaudioaudiocvpitch
Audio-rate Global FM with static formants
External sine into GLOBAL FM attenuated · RATIO A/B fixed, TRACK OFF · fundamental wobbles under stationary formants — vowel-through-vibrato effect
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: Sofia, Kbd, VCO, Output. Signals: 1 audio, 1 cv, 1 pitch.SofiaKbdVCOOutputRATIO TRACK A: OFFRATIO TRACK B: OFFRATIO A: 3RATIO B: 8PITCH CV V/OCT1v/octGLOBAL FMcvMAIN OUTaudioPitch1v/octSinecvInaudio11. low indexaudiocvpitch
Two-tap stereo spread (A vs B outs)
A OUT → delay L · B OUT → chorus R · FUND OUT centered dry — pseudo-stereo from one oscillator with element-specific processing
▸ Show diagram
Patch diagramPatch diagram with 5 modules and 6 connections. Modules: Sofia, Kbd, Delay, Mixer, Chorus. Signals: 5 audio, 1 pitch.SofiaKbdDelayMixerChorusRATIO A: 2RATIO B: 5PITCH CV V/OCT1v/octA OUTaudioB OUTaudioFUND OUTaudioPitch1v/octInaudioOutaudioChLaudioChRaudioChCaudioInaudioOutaudioaudiopitch
LFO / rhythmic formant pulses
OCTAVE = LO · fundamental ~2Hz · DAMP A very low, DAMP B high · ripples become audible bursts on each cycle — a complex pulse LFO / drone
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: Sofia, VCA, VCO, Output. Signals: 3 audio.SofiaVCAVCOOutputOCTAVE: LODAMP A: 5DAMP B: 80RATIO A: 6RATIO B: 9MAIN OUTaudioCVaudioInaudioOutaudioOutaudioInaudioaudio
Zadar-modulated formant scan
Zadar env → WARP A · second Zadar env → RATIO B with different shape · creates moving, breathy vocal gestures per note
▸ Show diagram
Patch diagramPatch diagram with 5 modules and 6 connections. Modules: Sofia, Kbd, Trig, Zadar, Output. Signals: 1 audio, 2 cv, 1 pitch, 2 trigger.SofiaKbdTrigZadarOutputSHAPE A: SINESHAPE B: SINERATIO TRACK A: OFFPITCH CV V/OCT1v/octWARP AcvRATIO BcvMAIN OUTaudioPitch1v/octTrigtrigTrig1trigTrig2trigOut1cvOut2cvInaudioaudiocvpitchtrigger
Reed/brass via square ripples and bright formants
SHAPE A/B = SQUARE · RATIO A ~4, RATIO B ~8 · DAMP B high for sustain · FUND·ELEM MIX high · breath-shaped envelope into VCA
▸ Show diagram
Patch diagramPatch diagram with 5 modules and 4 connections. Modules: Sofia, Kbd, BreathEnv, VCA, Output. Signals: 2 audio, 1 cv, 1 pitch.SofiaKbdBreathEnvVCAOutputSHAPE A: SQUARESHAPE B: SQUARERATIO A: 4RATIO B: 8DAMP B: 80FUND·ELEM MIX: 8PITCH CV V/OCT1v/octMAIN OUTaudioPitch1v/octOutcvCVcvInaudioOutaudioInaudioaudiocvpitch

Behaviors

FOF formant synthesis — time-domain formants non-zero RATIO + finite DAMP

Each cycle of the fundamental spawns a pair of decaying sine/square bursts (elements A and B). RATIO sets ripple density ≈ formant centre frequency, DAMP sets decay rate ≈ formant bandwidth. Because both elements are derived from the core, the spectrum stays strictly harmonic even with 'detuned-looking' ripples.

Two independent formants (A vs B) distinct RATIO A vs RATIO B

Classic vocal vowel approximation uses two formants spaced asymmetrically. Set RATIO A to a low ratio (F1) and RATIO B higher (F2), adjust ELEMENTS MIX for balance. Different vowel shapes emerge from distinct RATIO pairs.

Ratio tracking vs fixed-formant RATIO TRACK switch

Track ON → ripple density scales with fundamental, so the waveform shape is constant across pitch (sounds like a timbre). Track OFF → ripple frequency stays fixed, formant stays fixed in Hz — the hallmark of vocal/acoustic-sounding pitched playback.

Damp tracking vs fixed decay DAMP TRACK switch

Track ON → decay time scales with pitch (constant shape). Track OFF → decay time stays fixed in seconds, so at high pitches each cycle rings over the next, blurring toward a sustained resonance; at low pitches the ripple fully decays within a cycle.

Shape switch — sine vs square ripple SHAPE A or SHAPE B switch

Per-element selection of the ripple carrier. Sine is smoother and vocal; square adds odd harmonics producing more aggressive / buzzy / reed-like tones.

Warp reshapes density across the cycle WARP knob off-noon

Bends the ripple density distribution within one fundamental period. CW front-loads the density (strong attack, sparse tail); CCW pushes density to the end (sparse front, dense tail). Creates asymmetric articulation — plucks, bowed gestures, breathy attacks.

Pitch FM preserves waveform shape CV into PITCH FM

All elements follow modulation together. Audio-rate FM produces classic FM sidebands around the fundamental; the ripple density tracks so the formant shape remains coherent.

Global FM preserves spectral shape CV into GLOBAL FM

Only the base tone responds, ripples stay at their current frequencies. Yields formant-locked pitch wobble — source moves under fixed resonances, like a vocal tract with a changing pitched source.

Base tone mix — smooth sine to elements-only FUND·ELEM MIX

Min position: only the saturated fundamental — a warm, slightly driven sine. Max: only the ripple elements, which can be very bright. Intermediate positions emulate source+filter relationships without actually filtering anything.

Self-patching for wild timbres cables from A/B/IMPULSE OUTs to CV inputs

Manual explicitly encourages self-patching. Routing IMPULSE A → RATIO B, or A OUT → WARP B, or FUND OUT → DAMP A creates recursive internal modulation producing animal, metallic, or chaotic textures beyond static FOF.

Individual outs for multitracking / FX splits use A OUT / B OUT / FUND OUT separately

Each ripple is available at full amplitude without decay, plus IMPULSE outs give the raw decay envelopes. Route each to a different processor (delay on B, reverb on A, dry fundamental) for a pseudo-stereo spread from one oscillator.

Subsonic / LFO operation OCTAVE = LO

Fundamental drops below 1Hz. Ripple elements become audible grains riding a slow cycle — Sofia effectively turns into a rhythmic formant generator or complex LFO cluster.

Controls

Global PITCH Continuous pitch over a two-octave range. Sums with OCTAVE switch and all pitch CV inputs.
±12 semitones · fundamental range ~0.4Hz–12kHz combined with OCTAVE
Global OCTAVE 8-position rotary selecting octave band. LO enters LFO/subsonic territory.
LO · 64' · 32' · 16' · 8' · 4' · 2' · 1'
Global ELEMENTS MIX Balance between ripple elements A and B. Noon = 1:1.
CCW = A only · noon = equal · CW = B only · CV ±5V offset
Global FUND·ELEM MIX Balance between the fundamental (base) tone and the summed ripple elements at MAIN OUT.
min = fundamental only · max = elements only · CV ±5V offset
Global PITCH FM attenuator Attenuator for the PITCH FM input. Modulates the whole oscillator including ripples — preserves waveform shape.
0–10 · shape-preserving FM
Global GLOBAL FM attenuator Attenuator for GLOBAL FM input. Modulates only the base tone — preserves overall spectrum, ripples stay put.
0–10 · spectrum-preserving FM
Element A RATIO A Density of ripple A relative to the fundamental — sets the spectral peak / formant position. Min ≈ no ripple, max ≈ 8 octaves above fundamental.
0–10 · ~1 to ~240 ripples per cycle
Element B RATIO B Density of ripple B relative to the fundamental — second formant peak. Same scaling as RATIO A.
0–10 · ~1 to ~240 ripples per cycle
Element A RATIO A CV attenuator Bipolar attenuator for RATIO A CV input.
0–10 · for ±5V CV
Element B RATIO B CV attenuator Bipolar attenuator for RATIO B CV input.
0–10 · for ±5V CV
Element A DAMP A (slider) Decay rate of ripple A — behaves like Q/resonance (narrow spike at bottom, long ring at top) but is not a filter.
0 = narrow spike ~1% period · 100 = nearly undamped
Element B DAMP B (slider) Decay rate of ripple B.
0 = narrow spike ~1% period · 100 = nearly undamped
Element A WARP A Bends density distribution of ripple A across the cycle. Noon = uniform.
CCW = density rises toward end of cycle · CW = density front-loaded
Element B WARP B Bends density distribution of ripple B across the cycle.
CCW = density rises toward end of cycle · CW = density front-loaded
Element A RATIO TRACK A Miniature switch. Tracks element A's ripple density to pitch or keeps it fixed.
track = constant waveform shape · off = constant spectrum (formant)
Element A DAMP TRACK A Miniature switch. Tracks element A's decay rate to pitch or keeps it fixed.
track = constant waveform · off = constant decay time
Element B RATIO TRACK B Miniature switch. Tracks element B's ripple density to pitch.
track = constant shape · off = constant spectrum
Element B DAMP TRACK B Miniature switch. Tracks element B's decay to pitch.
track = constant shape · off = constant decay time
Element A SHAPE A Per-element switch between sine-like and square-like ripple.
SINE = cleaner tone · SQUARE = richer spectrum, more aggressive
Element B SHAPE B Per-element switch between sine-like and square-like ripple.
SINE = cleaner tone · SQUARE = richer spectrum, more aggressive

I/O

IN · 13

  • PITCH CV V/OCT 1V/oct · ±10V CV
    1V/octave pitch input, accepts voltages from -10V to +10V. Usable range depends on manual OCTAVE/PITCH settings.
  • PITCH FM audio rate capable · scaled by attenuator AUDIO
    Pitch FM that modulates fundamental and ripples together — preserves waveform shape.
  • GLOBAL FM audio rate capable · scaled by attenuator AUDIO
    FM that shifts only the base tone — preserves the overall spectral shape of the ripples.
  • ELEMENTS MIX -5V to +5V CV
    CV offsetting the A↔B balance.
  • FUND·ELEM MIX -5V to +5V CV
    CV offsetting the fundamental↔ripples balance.
  • RATIO A ±5V CV
    CV for ripple A density. Scaled by its attenuator.
  • RATIO B ±5V CV
    CV for ripple B density. Scaled by its attenuator.
  • DAMP A ±5V CV
    CV offsetting ripple A decay rate.
  • DAMP B ±5V CV
    CV offsetting ripple B decay rate.
  • WARP A ±5V CV
    CV offsetting ripple A density warping across the cycle.
  • WARP B ±5V CV
    CV offsetting ripple B density warping.
  • IMPULSE A ENV
    Individual decay envelope for element A — the raw amplitude curve without ripples. Useful for self-patching and triggering external gear.
  • IMPULSE B ENV
    Individual decay envelope for element B.

OUT · 6

  • MAIN OUT
    Final mix of the fundamental and the two ripple elements per the MIX controls.
  • FUND OUT
    Pure sinusoidal fundamental, unaffected by the triangle-core saturation.
  • A OUT ENV
    Element A ripple at full amplitude, without its decay envelope applied.
  • B OUT ENV
    Element B ripple at full amplitude, without its decay envelope applied.
  • IMPULSE A OUT GATE
    Decay envelope of element A, without the ripple carrier. Pulse-like shape spawning each cycle.
  • IMPULSE B OUT ENV
    Decay envelope of element B, without the ripple carrier.