Wavetable synthesis scans across up to 512 single-cycle frames via a Morph parameter to create evolving timbres

A wavetable in Surge XT contains up to 512 single-cycle waveforms (frames), each up to 4096 samples. The Morph parameter sweeps the playback position between frames; adjacent frames are interpolated for smooth timbral motion. Modulating Morph with an LFO creates animated, evolving tones. Holding Ctrl while dragging Morph snaps to exact frames for abrupt switching between distinct shapes. The wavetable oscillator intentionally outputs stairstepped waveforms without smoothing, creating harmonic aliasing (overtones repeating in the spectrum) — a characteristic 1980s wavetable synth quality distinct from the inharmonic aliasing of poor digital design. Formant shifts the pitch of the frame while the window pitch remains constant. Surge XT imports wavetables from Serum, Native Instruments, and others.

Examples

Load a vocal wavetable, modulate Morph slowly with an S-LFO to create a slowly morphing vowel formant motion. Use Ctrl-drag to snap between vowel frames for abrupt timbral jumps.

Assessment

What is harmonic aliasing in a wavetable oscillator, and why does it sound ‘musically pleasing’ compared to inharmonic aliasing? What does the Formant parameter do that Morph does not?