How to build your own chorus sound with Choroboros

Choroboros has five prebuilt chorus engines. Each one is built from two sound cores, and all of them share the same main controls: Rate, Depth, Offset, Width, Color, Mix and Trim. You learn the controls once, then switch engines to change the character.

• Green (classic): warm, for acoustic and synth sends. Free.
• Blue (modern): clean width on vocals and buses.
• Red (vintage): BBD and tape colour with vintage instability.
• Purple (experimental): strange textures and sound design. Free.
• Black (linear): dense ensemble voices.

Green and Purple are complete engines, free with no time limit, card or licence key. Download Choroboros from the downloads page, load it on a synth pad or a guitar, and try both. Green shows you the classic sound; Purple shows how far the same controls can go.

A simple way to learn any chorus:

1. Set Mix to about halfway so the effect is obvious.
2. Move Rate slowly, then Depth, and listen to how fast and how far the pitch moves.
3. Use Width to place the effect in the stereo field.
4. Use Color to shape the tone of the delayed signal.
5. Bring Mix back down until the effect supports the part instead of leading it.

The full licence adds Blue, Red and Black. Each has its own two cores and its own algorithm choice, so the same Rate and Depth settings feel different from engine to engine.

Create is the engine workshop inside Choroboros. It is part of the paid full licence, not the free edition. Create is documented on macOS so far; Windows support for Create is not confirmed yet.

A new engine goes through four stages:

1. Setup. Choose one core or two from the 17 supplied cores: the ten used by the prebuilt engines, plus seven more. Set the panel size and pick an artwork pack, or import your own.
2. Visuals. Choose the main knobs, the Mix knob and the slider thumb. Two-core engines also show switch artwork.
3. Details. Give the engine a name, a thumbnail, a description and tags for its library card.
4. Review. Check the summary, choose Save Engine, then Open Library to load it.

In the Sound workspace you tune the delay, motion, character and saturation controls that define the engine. You can start from a factory recipe with Modify, which makes an editable copy.

The 17 cores, as named in the Create guide: Lagrange 3rd, Lagrange 5th, Cubic, Thiran, BBD, Tape, Phase Warp, Orbit, Flange, Barber Pole, Ensemble, Multi Rate, Granular, Formant, Linear, Stochastic and Phase Vocoder.

Create keeps sound and artwork together. Choose panel artwork, knob sheets, a slider thumb and a thumbnail from the supplied parts or your own PNG files. All 26 Kaizen DSP artwork designs are free to download; using them in Choroboros needs Create, which comes with the paid full licence.

Engines save to your local library. Signed .kzn files can move between Choroboros installs, and .kzn.zip bundles include your artwork. Exporting needs an active saved licence and an internet connection.

• macOS: AU, VST3, AAX and standalone, Apple Silicon and Intel.
• Windows x64: VST3. There is no Windows AAX version.
• Current version: 1.0.5.
• Free edition: Green and Purple, no time limit.
• Full licence: US$49.99 one time, plus applicable taxes at checkout. It includes all five engines, Create, lifetime updates, and a refund if you request it within 30 days of purchase (see the refund policy). No subscription.

• Choroboros: engines, sound examples and download.
• Create: the engine builder in detail.
• Fold: a free stereo width plugin from Kaizen DSP, if you want to shape where your chorus sits in the stereo field.