Wavetable Synthesis — A Tiny Buffer Becomes an Oscillator

A sampler usually reads a longer recording. A wavetable oscillator repeatedly reads a very short stored waveform. Loop that tiny buffer fast enough and it becomes a pitched oscillator.

Sampling and synthesis meet here: we are still reading samples from memory, but instead of treating the buffer as a recorded event, we repeat a short cycle continuously.
Akai S1100

1. One cycle in memory

Choose a waveform or draw your own. The dots are the stored table values; the blue read head repeatedly scans from the beginning of the table back to the beginning.

Drag directly on the table to draw a custom single-cycle waveform.

128 samples
0 → 127 → 0 → …
oscillator pitch is controlled by how quickly we move through the table

2. The buffer is tiny — but it repeats

Sampler
Longer buffer
Usually read as an event
May use start/end/loops
Granular
Longer buffer
Many tiny windows
Many independent read positions
Wavetable
Tiny cyclic buffer
Repeated continuously
Acts like an oscillator
The storage principle is the same. What changes is the strategy for reading the buffer.

3. More than one table: move through timbre

Modern wavetable synths commonly store a sequence of related single-cycle waveforms. The wavetable position chooses where we are between them.

Here the table moves through four frames: sine → triangle → saw → complex. Intermediate positions are interpolated.

table A + interpolation → table B
Interpolation again. We met the same idea when the sampler read between discrete sample positions. Here it can also estimate a waveform between two stored table frames.

4. Wavetable position becomes a modulation destination

Once position is a controllable number, everything from the synthesis chapter applies again. An LFO can move through the table slowly; an envelope can sweep it once; velocity or another controller could select a different timbral region.

LFO / ENVELOPE / CONTROLLER → WAVETABLE POSITION → TIMBRE
Nothing fundamentally new happened. We created another parameter that can be changed over time.

5. And all our synth architecture still applies

The wavetable is only the sound source. After it, we can use everything we already learned.

WAVETABLE OSCILLATOR → ADSR → FILTER → FILTER ENV → LFO → EFFECTS → OUTPUT

Exactly the same is true for the sampler and granular engine:

SAMPLE / GRANULAR SOURCE → ADSR → FILTER → LFO → EFFECTS → OUTPUT
This is the big synthesis/sampling connection: oscillator, sample buffer, granular cloud and wavetable are different ways of creating or reading the source signal. The later stages of the instrument can remain largely the same.

6. Sampling chapter summary

Buffer
Store recorded samples.
Key spanning
Change read speed to change pitch.
Interpolation
Estimate values between stored positions.
Time stretch
Rearrange/window material to separate time from pitch.
Granular
Many tiny independently controlled reads.
Wavetable
Repeat tiny waveform buffers as oscillators.
Before DSP: all of these source techniques can feed the envelopes, filters, modulation, polyphony and effects architecture from the synthesis chapter. We have been changing the source, not throwing away the rest of the instrument.