Oscillators

The oscillator is the part of a synthesizer that makes the raw sound. Before any shaping, this is the tone you start with. Kiwisynth has three main oscillators, a sub oscillator and a noise source, and you mix them together. The third oscillator (OSC3) is silent by default — turn its Level up to bring it into the mix.

Choosing how an oscillator works

Each main oscillator has a mode. The mode decides how it makes its sound.

Mode. Five choices.

• Wavetable. The oscillator plays through a row of waveforms and you can move between them. This is the main mode, and the controls below assume it.
• SuperSaw. The oscillator becomes a thick stack of slightly detuned sawtooth waves in one step, the wide sound used in dance leads.
• Karplus-Strong. The oscillator models a plucked string instead of playing a waveform. Its controls are described further down.
• Modal. The oscillator becomes a tuned resonator, like striking a bell, a marimba bar or a chime. It rings at the played pitch and then decays. Its controls are described in the Modal section further down.
• Granular. The oscillator becomes a cloud of tiny overlapping grains read from a source, either a loaded sample or the oscillator's own wavetable. It is the mode for time-domain texture, evolving pads and broken, scattered sounds. Its controls are described in the Granular section further down.

Wavetable controls

WT Pos. Wavetable position. A wavetable is a row of single-cycle waveforms. This control chooses which point in that row you hear, and moving it changes the tone. Adding movement here gives a sound that evolves as it plays.

Warp. A second way to reshape the waveform, on top of the wavetable. Choose a style: Bend reshapes the wave, PWM thins and fattens it, Sync adds a hard edge, Wavefold drives it until it folds over for bright harmonics. Off means no warping.

Warp Amt. How much the chosen warp is applied. At the lowest setting there is no effect.

Importing your own wavetables

Beside the wavetable display, the Import WAV... button loads your own audio file as the oscillator's wavetable, so you are not limited to the factory set. It is available on OSC1 and OSC2 in the advanced editor. Clicking it offers two ways to read the file:

• Single cycle / short table. Treats the file as one waveform and resamples it to a clean, pitched table. Use this for a single-cycle wave or a short, clear tone when you want a precise custom timbre.
• Scan long source (evolving). Slices a longer file into many frames laid out in order, so the WT Pos control scans through the recording as a moving sound. This is the one for vocal phrases, field recordings and other evolving textures: sweep WT Pos, by hand or with an LFO or envelope, to travel through the source.

Importing switches the oscillator to Wavetable mode so you hear the result at once. After import, every wavetable control applies as usual, and the imported table is a normal modulation destination through WT Pos.

A preset that uses an imported wavetable is saved as a self-contained .kwsz file that carries the audio data alongside the preset. Share that file and the person who opens it hears exactly what you made, with no need for your original .wav. Presets that use only factory wavetables stay in the plain .kwpreset format.

Tuning

These set the pitch of the oscillator.

Octave. Shifts the oscillator up or down in whole octaves. Use it to place the two oscillators in different registers.

Semi. Shifts the pitch in semitones, the steps between neighbouring keys.

Tune. A fine pitch offset, smaller than one semitone. A small amount of tune between the two oscillators makes the sound thicker.

Unison and drift

Unison stacks several copies of the oscillator for a fuller sound.

Unison. How many copies are stacked. One is a single, plain voice. More copies give a wider, thicker sound.

Detune. How far apart in pitch the copies are spread. A little gives gentle thickness, more gives a broad, shimmering sound.

Drift. Each copy slowly wanders in pitch on its own. Drift sets how far it wanders. This keeps the sound alive and stops the copies locking into a fixed pattern.

Drift Rate. How quickly that wandering happens.

Level and placement

Level. The volume of this oscillator in the mix. The second oscillator starts silent, so you will not hear it until you raise its level, or until you use it as an FM source described below.

Mute. Each oscillator tab has a small mute button beside it, marked with three dots. Click it to silence that oscillator without changing its Level, then click again to bring it back. Because it leaves the Level untouched, it is the quick way to audition one oscillator on its own while you shape it: mute the other two, listen, then unmute. Alt-click a mute button to isolate that oscillator in a single step, muting the other two at once, and alt-click it again to bring all three back. The button lights when the oscillator is muted, and the mute is saved with the preset. The mute buttons stay visible on every tab, so you can silence OSC2 and OSC3 while you are looking at OSC1.

Pan. Places the oscillator to the left or right.

Width. How widely the unison copies are spread across the stereo image. More width gives a bigger, more spacious sound.

Curve. Shapes how the unison copies are distributed across the detune range and stereo image. The middle setting spreads the copies evenly. Turn Curve down to pull the copies in toward the centre — the inner voices cluster near the centre pitch and the centre of the stereo image, leaving a strong fundamental with a halo of detune around it. Turn Curve up to push the copies out toward the edges — voices fan out away from the centre, giving a hollow, swarming sound with no clear fundamental. Centred is the versatile starting point; clustered is the right shape for chord stabs and trance leads that need a present centre; pushed-out suits psy growls and aggressive wavetable scrubs where the spread is the sound.

In SuperSaw mode the Curve knob owns the JP-8000-style shape that was previously fixed. A value just above the middle (around 0.6) matches the classic JP-8000 character; the default centre is slightly more even, and the extremes give characters the JP-8000 could not.

SuperSaw splits its character across two controls, the same way the original hardware did. Detune sets how far the stacked saws spread in pitch, from a tight, focused stack to a broad, shimmering wall. SS Mix sets the balance between the centre saw and the detuned side saws: low keeps a strong, present centre pitch, high pushes the side saws forward for the hollow, wide chorus. The saws are band-limited, so the stack stays smooth and clean as you play up the keyboard instead of turning harsh and gritty in the high register.

Choosing SuperSaw sets up a ready-made stack at once: it raises Unison and Detune to a classic seven-saw spread, so you hear the wide sound straight away without dialling it in. Adjust Unison, Detune and SS Mix from there to taste. Loading a preset never triggers this, so a preset's own settings are kept.

FM

FM, frequency modulation, uses one oscillator to modulate another. It produces metallic and bell-like tones that the oscillators cannot make on their own.

FM Mode. Switches FM on or off.

FM Depth. How strongly a modulator shapes its carrier. More depth gives a more extreme, more metallic result.

FM Feedback. Lets Oscillator 2 also modulate itself, adding a rougher, brighter edge.

When FM is on, a modulator is heard through its carrier even if its own level is down.

FM Algorithm

The algorithm chooses how the operators are wired. An operator is just an oscillator acting as a carrier (heard directly) or a modulator (heard only through the carrier it shapes). There are four operators: Op 1 is Oscillator 1, Op 2 is Oscillator 2, Op 3 is Oscillator 3, and Op 4 is an extra pure-sine modulator with its own ratio and feedback.

Off and Two Op Stack. The classic pair: Oscillator 2 modulates Oscillator 1. Oscillator 3 plays on its own. This is the original FM behaviour.

Dual Pair. Two modulator and carrier pairs played together: Oscillator 2 modulates Oscillator 1, and the Op 4 sine modulates Oscillator 3. The two carriers are summed. This is the bell and carillon sound, where two independently moving pairs give a rich, inharmonic ring.

Stack Of 3. A three-deep chain: Op 4 modulates Oscillator 2, which then modulates Oscillator 1. Deeper, more complex spectra from a single carrier.

Dual To One. Both Oscillator 2 and the Op 4 sine modulate Oscillator 1 together. Oscillator 3 plays on its own.

Per-operator envelopes

Each operator has its own attack, decay, sustain and release. For a modulator the envelope shapes the modulation amount over time, so a fast decay gives the bright metallic strike of a bell that quickly settles into a purer tone. For a carrier the envelope shapes that carrier's own level, so one carrier can ring long while another fades fast. By default every operator envelope holds a steady full level, so the FM behaves as if the envelopes were not there until you shape one.

Op 4 and ratios

Op 4 Ratio. The pitch of the Op 4 sine relative to its carrier. Whole numbers stay harmonic; in-between values like 3.5 or 7.02 give the inharmonic, clangourous partials that make convincing bells.

FM Ratio Offset. A small global detune of the modulators against the carriers. Just off 1.0 the modulators beat slowly against the carriers for a living, shimmering drift. At 1.0 it is off.

Op 1, Op 3, Op 4 Feedback. Self-feedback for each of those operators, the same rough, brighter edge as FM Feedback (which is Op 2) but per operator. A little feedback on the top modulator gives a noisy strike at the attack.

Karplus-Strong controls

When an oscillator is in Karplus-Strong mode it models a plucked string. These controls replace the wavetable controls.

Damping. How quickly the string loses energy and the note dies away. Less damping rings longer.

Brightness. How bright or dark the string sounds.

Pick Pos. Where along the string it is plucked. Plucking near the end gives a thinner, sharper tone; nearer the middle gives a rounder one.

Stretch. How much the decay differs between low and high notes, so the string behaves more or less evenly across the keyboard.

Pick Dir. The direction of the pluck, up or down. A subtle change to the attack.

Modal controls

When an oscillator is in Modal mode it becomes a tuned partial-bank — a physical model of an idiophone, the family that includes bells, marimbas, glockenspiels and tubular chimes. Striking the keyboard excites six tuned partials that ring and decay together. These controls replace the wavetable controls.

Damping. How quickly the partials die away. At the lowest setting the note rings for a couple of seconds; at the highest it taps and is gone. Lower partials always sustain longer than higher ones, which is how real bells and bars behave.

Inharmonicity. Where the partials sit relative to the played pitch. At zero the partials are pure harmonics, giving a rod-like, near-tonal sound that still has a struck character. At maximum the partials follow the stretched series of a tubular bell, with that characteristic shimmering, slightly-out-of-tune bell tone.

Pos. Where on the imaginary bar or bell the strike lands. Edge strikes (near 0 or 1) excite every partial brightly. Centre strikes (around 0.5) sit on the nodes of even partials and kill them, leaving a warmer, hollower tone.

Modal mode is mono and ignores Width, Unison and Detune. Like a string, the resonator is a one-dimensional object.

Granular controls

When an oscillator is in Granular mode it stops playing a continuous waveform and instead sprays a cloud of short, overlapping grains. Each grain is a tiny windowed snippet read from a source. Play a note and the cloud tracks the keyboard pitch, the same way a sampler would. These controls replace the wavetable controls.

Source. Where the grains read from. Wavetable scans across the oscillator's own wavetable, turning a static table into evolving texture. Sample reads from a loaded audio clip (see Sample sources below). With no sample loaded, Sample falls back to the wavetable scan so the slot always makes sound.

Density. How many grains are spawned each second. Low densities are sparse and rhythmic, with audible gaps between grains. High densities pack the grains into a continuous, smooth cloud. This is the main control for how thick the texture feels.

Size. How long each grain lasts. Short grains buzz and sound granular and broken; long grains are smooth and tonal because each one carries more of the source waveform. Size and Density together set how much the grains overlap.

Pos. The point in the source the grains read from. Sweep it slowly, by hand or with a slow LFO, to drift through the source material for a continuously evolving pad.

Spray. Random scatter applied to each grain. It jitters both the read position and the stereo placement, so higher values spread the cloud wider and make it looser and less repetitive.

Jitter. Per-grain random detune in cents. A few cents adds gentle shimmer and chorus-like thickness; large values pull the cloud into chaotic, dissonant territory.

Reverse. The chance that any given grain plays backwards. A little adds a sucking, blurred quality; at maximum every grain reverses.

Granular mode is its own time-domain process and ignores Unison, Detune, WT Pos and FM. When density and size are pushed very high the engine caps the number of simultaneous grains and reuses the oldest, so the cloud stays smooth and never runs away.

Sample sources

A Granular oscillator set to the Sample source reads from an audio clip loaded into that slot. The factory clips (a struck metal tone, a breath noise bed and a vinyl-crackle texture) are built in and ready to granulate. This is also the path that brings your own recorded audio into the synth: a granular cloud over a sampled voice, field recording or drum loop is a very different starting point from a wavetable, and it is what lets Kiwisynth granulate both a resynthesized wavetable and a real recording in the same patch.

Import Sample... Beside the wavetable display, the Import Sample button loads your own audio file (WAV or AIFF) as the granular sample for the current oscillator. It is available on all three oscillators. Importing switches that oscillator to Granular mode with the Sample source selected, so you hear the grain cloud at once. Stereo files are summed to mono and the clip is capped at about 30 seconds. The imported audio travels with the preset: saving a patch that uses an imported sample writes a self-contained .kwsz bundle (the same format the wavetable importer uses), so a shared preset keeps its sample.

Layering with three oscillators

With three oscillators you can build patches that need three independent voices breathing inside one note:

• Chord-octave stacks for keys and pads. Set OSC1 to the root, OSC2 to +12 semitones, OSC3 to +19 (a fifth above the octave) and route ModEnv2 to OSC3 Level so the top voice rises in after the chord. The result is the breathing-octave feel of a Rhodes chord or drawbar organ.
• Pluck = transient + body + ring. Use OSC1 in Wavetable for the body, OSC2 in Karplus-Strong for the ring, OSC3 in Modal for the bell-like attack transient (high damping, low position).
• Pad layer-cake. OSC1 for the analog body, OSC2 for a vowel/formant mid layer, OSC3 in Modal with high inharmonicity for the slowly-evolving bell-like top.
• Bass = sub + body + grit. Sub oscillator for the fundamental, OSC1 for the mid-body saw stack, OSC3 with low damping and high inharmonicity for the formant-grit top.

Each oscillator's amplitude can be shaped independently by routing one of the Mod Envelopes to its Level — see the Modulation page for the ModEnv → OscN Level pattern.

Sub oscillator

The sub oscillator adds weight below the main oscillators. It plays an octave down.

Sub Shape. Morphs the sub between a pure, smooth sine and a fuller square.

Sub Level. The volume of the sub in the mix. Raise it for more low end.

Noise

The noise source adds an unpitched layer: air, breath, or the noisy part of an attack.

Noise Level. The volume of the noise in the mix.

Noise Cutoff. Noise has its own simple filter. This sets where that filter acts, which controls how bright or dark the noise sounds.

Noise Filter Mode. Whether the noise filter keeps the low part of the noise, the high part, or a band in the middle.

Pick Attack. Adds a short burst of noise at the start of each note, like the click of a pluck or a key. Used mainly by Simple Mode.

Voice behaviour

These controls sit with the oscillators because they affect the raw voice.

Warmth. A gentle saturation added before the filter. It thickens the tone and adds harmonic richness. It is always slightly present, and is part of the Kiwisynth character. Peak-preserving — heavy settings add tube-like grit without making the patch noticeably louder than a clean note.

Note Bloom Rate. While a note is held, its tone slowly fills out, gaining harmonic richness over several seconds. This happens on every preset, and short notes never trigger it. Note Bloom Rate sets how long a held note takes to reach its full bloom: a low setting fills the sound out within a second, a high setting keeps it opening for many seconds. The same timing drives the Bloom modulation source described on the Modulation page.

Glide. When raised above its lowest setting, the pitch slides from one note to the next instead of jumping. Also called portamento.

Voice. Poly lets several notes sound at once, for chords. Mono allows only one note at a time, the usual choice for basses and solo lines.