Oscillators

Wave Osc

The wavetable oscillator — scan through banks of single-cycle waveforms to make timbres that morph, drift, and evolve.

What is a Wave Osc?

A wavetable oscillator is a sound source that, instead of generating a single fixed waveform like a VCO, plays back from a *table* of stored single-cycle waveforms and lets you scan smoothly through them in real time. Each waveform in the table — a frame — is one period of audio: 256 samples, sometimes 2048 samples. A position knob picks which frame to play, and as you turn it the oscillator crossfades between adjacent frames, producing a continuously evolving timbre.

Where a VCO gives you four classical shapes (sine, triangle, saw, square) and a fixed harmonic spectrum, a wavetable can hold *anything*: sampled instrument cycles, mathematically constructed harmonic series, formant shapes, organ stops, FM-style metallic spectra, the noisy cycles found in vocal formants. A single table might contain 64, 128, or 264 frames that morph through completely different timbres. The instrument becomes less about choosing a waveform and more about *navigating* a small library of them.

The technique was invented by Wolfgang Palm at PPG in the late 1970s and reached its full expression in the PPG Wave 2.2 and Waldorf Microwave. Hardware Eurorack modules like the Synthesis Technology E370 and Erica Synths WTx brought it into modular. The defining sound — bright, slightly digital, *animated* — comes from one thing: smoothly modulating the position over time, so the timbre never sits still.

Modern wavetable oscillators use bandlimited tables (one version of each frame for each pitch range, to prevent aliasing when playing high notes) and either linear or higher-order interpolation between samples and frames. The result is a digital sound that, when scanned slowly, can be as expressive as any analog oscillator and far richer in spectrum.

Our Wave Osc

Our Wave Osc ships with 98 wavetables, each containing 264 frames of 256 samples. The tables come from a wide cross-section of synthesizer history — PPG-style classic shapes, Microwave-style harmonic morphs, formant tables, FM-style metallic banks — selected to give a useful range without being overwhelming. The currently active table is shown live in the panel as you scan.

Position morphs through the table with linear crossfading between frames, controlled by the Pos knob and the Pos CV input. There are also Start and End knobs that constrain the position to a slice of the table, so you can lock the morph into just the section that sounds best for your patch — useful when a table has 264 frames but only 30 of them are what you want.

Standard 1V/Oct tracking, ±24 semitone coarse + ±100 cent fine tuning, FM with attenuverter, hard sync, and a separate SUB output (a clean sine, one octave down) for bass reinforcement. Stays clean and glitch-free even when sweeping position fast under modulation.

In a patch

A wavetable oscillator slots into the same place as any other voice source: WaveOsc → VCF → VCA → output. The interesting part is what you do with position. Patch a slow LFO (say 0.05 Hz) into the position CV and the timbre slowly evolves over ~20 seconds — perfect for ambient pads. Patch an envelope and the timbre sweeps once per note, like a filter sweep but in spectral space rather than frequency space.

Two wavetable oscillators detuned by a few cents and morphing through different positions give an enormous, animated stereo sound — the trick used in countless modern preset libraries. Add a sub-oscillator for low-end weight, route through a chorus for thickness, and you have a complete super-saw replacement voice with far more character.

Audio-rate position modulation is its own world. Patch one wavetable's audio output into another's position CV (with attenuation), and you get a chaotic, ringing, FM-adjacent timbre — somewhere between wavetable scanning and phase distortion. This is where the technique stops being a *cleaner* sound source and becomes its own kind of synthesis.

Inputs

V/Oct (cv) — Pitch input. 1V per octave standard. 0V = C4. Controls the playback rate of the wavetable frames.
FM (cv) — Frequency modulation input. Amount scaled by the FM attenuverter. Use for vibrato or FM-style timbral effects.
Pos CV (cv) — Position modulation input. Adds to the Position knob value. Patch an LFO here for scanning through wavetable frames, or an envelope for per-note timbral evolution.
Sync (gate) — Hard sync input. Resets the oscillator phase on each rising edge. Creates harmonically complex tones when synced to another oscillator at a different pitch.

Outputs

Wave (audio) — Main wavetable output. The current interpolated waveform at the given position. This is the primary output for most patches.
Sub (audio) — Sub-oscillator output. A pure sine wave one octave below the main pitch. Level controlled by the Sub knob. Mix with the main output for added bass weight.

Controls

Position — Wavetable frame position from 0 to 1. Sweeps through all frames in the current table. At 0 you hear the first frame; at 1 the last. Values in between crossfade smoothly. This is the most important knob - try sweeping it by hand first.
Coarse — Coarse tuning in semitones, +/-24 (two octaves up or down).
Fine — Fine tuning in cents, +/-100 (one semitone). Use for detuning against other oscillators.
FM Atten — FM attenuverter, -1 to +1. Scales the FM input. Negative values invert the modulation.
Sub Level — Sub-oscillator level from 0 (off) to 1 (full). Blends the sub-octave sine into the Sub output.
Start — Start frame position (0 to 1). Limits the low end of the Position sweep range. Useful for focusing on a specific section of the wavetable.
End — End frame position (0 to 1). Limits the high end of the Position sweep range. Together with Start, you can isolate the best-sounding portion of any wavetable.
Table — Wavetable bank selector, 0 to 198. Each bank is a different set of 264 waveform frames. Explore these to find wildly different timbres - from analog emulations to digital textures to vocal formants.

Inspired by

A classical wavetable oscillator topology: a bank of single-cycle frames, a position knob that crossfades between them, V/Oct tracking, FM, and a sub-oscillator. Linear-interpolated frame morphing follows the Wolfgang Palm / PPG lineage; the 98 included tables come from a wide range of synth sources.

PPG Wave 2.2
Waldorf Microwave
Synthesis Technology E370
Erica Synths WTx

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