deiosc is a user oscillator for the KORG Minilogue xd. It is aimed at creating pads: sustained textures that evolve while a note is held. It does not generate monotone notes or sequences; it produces a continuous signal whose timbral content changes autonomously.
Sound composition
The oscillator combines two components:
- Sine base with saturation: provides a smooth and stable timbre.
- Inharmonic component: built from partials at powers of the golden ratio (φ). It adds a brighter character and introduces a slight tension.
The mix between the two varies automatically over a cycle of approximately 51 seconds. This modulation is internal and does not use the synthesizer’s LFO. The user can adjust the overall presence of the inharmonic component, but not the speed or shape of the modulation, which are fixed by design.
Beating
The oscillator includes beating whose intensity depends on the presence of the inharmonic component. When this component decreases, the beating becomes more audible; when it increases, the beating is attenuated. The beat period is fixed and does not depend on the note played.
Sub-oscillator
Optionally, a sub-oscillator can be added to reinforce the low frequencies.
Controls
- SHAPE: controls the overall presence of the inharmonic component. 0 = base only; 1 = maximum.
- SHIFT + SHAPE: controls the intensity of the beating. 0 = no beating; 1 = maximum.
- EDIT 1: controls the sub-oscillator level.
These controls adjust the overall presence of the components, but do not alter the automatic internal modulation.
Usage
Load the unit file into a user slot of the minilogue xd’s Multi Engine. Select the oscillator and adjust the controls according to the desired result. The synthesizer’s LFO remains available for other functions.
The source code and unit file are available in the repository: https://github.com/deibit-dev/deiosc
Design details
For the visitor interested in delving deeper into how the construction process was carried out, I created a post with design details, some implementation details, and the creation process: Building a custom oscillator for the KORG Minilogue xd.
