by Robin Vincent | 5,0 / 5,0 | Approximate reading time: 1 Minute
Opera Rotas

Opera Rotas  ·  Source: Spherical Sound Society


Based on the Yamaha soundchip from the Sega Megadrive the Opera Rotas is a mutant generative drum machine full of FM synthesis.


Opera Rotas

The sound engine is the Yamaha OPL2 sound chip and can handle a world of sounds from simple tones, bells and chimes through edgy FM, clash, smash, chiptune and fuzzy logic beeps. But the trick with this drum machine lies somewhere in the meddling of rhythms and generation of beats.

It has 8 channels of sound with 8 notes of polyphony with 16 knobs and 16 buttons to kick off your programming and sound sculpting. Quite what happens after that is not entirely clear but Spherical Sound Society describe is as:

Opera Rotas has the weirderst workflow. Even if you can insert and edit notes and parameters one by one, like “normal” drummachines, where the magic happens is when you engage in his “auto” mode. In this mode it performs a kind of parameter lock of the current channel setting, and in every step in jumps to the next channel, editing the parameter that you are currently tweaking. It produces all kind of serendipitous movements and sonic mutations, ranging from techno, to chiptune and sometimes touches of classical mussic and alienesque landscapes.


The firmware is open source and there’s plenty more development to come in the shape of MIDI implementation. You can obtain one fully built, as a full kit, part kit or just the PCB. New stock should arrive in 2-3 weeks.

Check out the video below for sound examples and how the rhythms develop.

More information

  • Spherical Sound Society website.


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More Information

Opera Rotas

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