An expressive, quasi-Ptolemaic semi-modular synthesizer.
Four bodies revolve with uniform circular motion, each around one of the others or, in the case of the first body, a fixed central point. Each body around which no other body revolves serves as an oscillator, producing sound. The interpretation of these terminal bodies as oscillators depends on their positions as viewed from a point that is either at the fixed center of revolution or nearby, at a point called the "equant," more in honor of Ptolemy than in strict adherence to his system (hence "quasi-Ptolemaic"). In the engine's fully modulated state (i.e., with the "Demodulate" knob turned all the way down), only the angle formed by a reference line and the line connecting the equant to the terminal body matters to the sound, just as, in Ptolemy's system, the distances of the heavenly bodies are unknown. This system of sound generation closely resembles frequency modulation (FM) synthesis. The relative speeds of revolution of the various bodies have their analogues in the frequencies of so-called "carrier" and "modulator" (or "operator") waves in traditional FM synthesis. Accordingly, the interface allows both ("coarse") whole-number and ("fine") fractional variation of these relative frequencies, producing a wide array of timbres, from the pure and simple to the densely inharmonic. Many mutually modulatable parameters are configurable by the user, and a robust system of randomization facilitates sonic exploration and discovery.
Features:
"Orbital Modulation" (OM) synthesis
Randomizable modulation matrix
Built-in effects chains