Oscillators

Synome features two independent oscillators with saw/pulse morphing, FM synthesis between them, hard sync, and a noise generator. Both oscillators feed into a mixer before the filter stage.

Oscillator 1

Parameter	ID	Range	Default	Unit	Description
`osc1_shape`	0	0.0–1.0	0.0	—	Waveform morph: 0 = sawtooth, 1 = pulse
`osc1_coarse`	1	-24–+24	0	st	Coarse pitch in semitones
`osc1_fine`	2	-100–+100	0	cents	Fine pitch in cents
`osc1_mod_lfo`	3	on/off	off	—	Enable LFO → pitch modulation
`osc1_mod_env`	4	on/off	off	—	Enable Mod Envelope → pitch modulation
`osc1_fm_amount`	5	0.0–1.0	0.0	%	FM depth (OSC2 → OSC1 frequency)
`osc1_fm_env`	6	on/off	off	—	Mod Envelope → FM amount
`osc1_fm_lfo`	7	on/off	off	—	LFO → FM amount

FM Synthesis

OSC2’s output modulates OSC1’s frequency. The FM amount is the modulation index:

osc1_freq_effective = osc1_freq × (1 + osc2_output × fm_amount)

FM amount can be further modulated by the Mod Envelope and/or LFO for dynamic timbral changes.

Oscillator 2

Parameter	ID	Range	Default	Unit	Description
`osc2_shape`	13	0.0–1.0	0.0	—	Waveform morph: 0 = sawtooth, 1 = pulse
`osc2_coarse`	14	-24–+24	0	st	Coarse pitch in semitones
`osc2_fine`	15	-100–+100	0	cents	Fine pitch in cents
`osc2_sync`	16	on/off	off	—	Hard sync: OSC2 resets OSC1 phase
`osc2_mod_lfo`	17	on/off	off	—	Enable LFO → pitch modulation
`osc2_mod_env`	18	on/off	off	—	Enable Mod Envelope → pitch modulation

Hard Sync

When enabled, OSC2’s phase wrap resets OSC1’s phase to zero. This creates complex harmonics that change with OSC1’s pitch. Classic sync sweep: tune OSC1 higher while synced to OSC2.

Waveform Morphing

Both oscillators morph continuously between sawtooth and pulse:

output = saw × (1 - shape) + pulse × shape

Shape Value	Waveform
0.0	Pure sawtooth
0.25	75% saw / 25% pulse
0.5	50/50 blend
0.75	25% saw / 75% pulse
1.0	Pure pulse (50% duty cycle)

Oscillator Modes (Future)

The oscillator engine supports pluggable synthesis modes:

Mode	Index	Description	Status
Analog	0	Saw/pulse morphing (current)	✅ Available
Wavetable	1	Scan through wavetable frames	🔮 Planned
Granular	2	Granular cloud synthesis	🔮 Planned
Physical	3	Physical modeling / Karplus-Strong	🔮 Planned

Mixer

The mixer blends the two oscillators with a noise generator before the filter:

Parameter	ID	Range	Default	Unit	Description
`mix_osc1`	8	0.0–1.0	0.7	%	OSC1 level
`mix_osc2`	9	0.0–1.0	0.0	%	OSC2 level
`mix_noise`	10	0.0–1.0	0.0	%	Noise level
`mix_noise_type`	11	0–1	0	—	0 = white noise, 1 = pink noise
`pitch_mod_source`	12	0–1	0	—	Pitch modulation source selector

Noise Types

Type	Value	Spectrum	Use Case
White	0	Equal energy per frequency	Bright, hissy — cymbals, wind
Pink	1	Equal energy per octave (−3 dB/oct)	Warmer, natural — ocean, rain

Pink noise uses a 7-stage Voss-McCartney algorithm for accurate 1/f spectral rolloff.

Pitch

Parameter	ID	Range	Default	Unit	Description
`pitch_bend_range`	67	0–24	2	st	Pitch bend wheel range
`pitch_mod_amount`	68	0–24	0	st	Pitch modulation depth
`vibrato_rate`	69	0.1–15	5.0	Hz	Vibrato speed
`vibrato_depth`	70	0.0–1.0	0.0	st	Vibrato depth

Pitch Modulation Routing

When osc1_mod_lfo or osc2_mod_lfo is enabled, the LFO modulates that oscillator’s pitch by pitch_mod_amount semitones. Similarly, osc1_mod_env / osc2_mod_env routes the Mod Envelope to pitch.

final_freq = base_freq × 2^((coarse + fine/100 + pitch_mod) / 12)

Where pitch_mod is the sum of enabled modulation sources × pitch_mod_amount.

Output

Parameter	ID	Range	Default	Unit	Description
`volume`	28	0.0–1.0	0.7	%	Master volume
`mono`	29	on/off	off	—	Mono mode (single voice)
`legato`	30	on/off	off	—	Legato (no envelope retrigger on overlapping notes)
`unison_mode`	31	0–3	0	—	Unison voice stacking
`pan`	32	-1.0–+1.0	0.0	—	Stereo pan (equal-power law)
`glide`	33	0–2000	0	ms	Portamento time

Unison Modes

Value	Mode
0	Off
1	2× unison
2	4× unison
3	8× unison

Master

Parameter	ID	Range	Default	Unit	Description
`master_drive`	71	0.0–1.0	0.0	%	Soft saturation (tanh waveshaper)
`voice_count`	72	0–3	2	—	Maximum polyphony (4/8/12/16)
`master_tune`	73	-100–+100	0	cents	Global tuning offset

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