OPERA ROTAS is a mutant, generative drum machine. It's built around a Yamaha OPL2 FM audio chip, a close cousin of the one used in the Sega Genesis / Megadrive consoles.

At the core, it has a real Yamaha OPL2 audio chip and live sounds bonkers, brutal. It's all body and weight while being crystal clear and punchy. The videos don't do aural justice but it serves to get an idea.

The original firmware is the generative drum machine of the demo, but there´s another alternative firmware that turns it into a 9 voice polyphonic synth. You can get both. In fact I recommend it, as it as having 2 machines in one.

The project will go open source at some point while I retain the hardware fabrication rights.

It comes in 3 flavours:

• Full kit. Everything you need to build one (The Yamaha chips of the OPL2 tested). You need to solder it. Beginners level.

• Basic kit. The PCB, the OPL PCB plus a programmed SMT32 microcontroller and the tested Yamaha chips of the OPL2.

• The main PCB, the OPL2 PCB and the programmed microcontroller. You have to source the rest of the components, and build it.

The PCB comes with all passive components presoldered except that ones that you have to source (that comes included in the full kit):

-16 switch buttons. -16 pots (vertical b10k. Any linear vertical pot will be ok) -OLED Screen. -2x20 pin female sockets (for the bluepill microcontroller) -The programmed bluepill itself. -And components for the OPL2.

Manual, schematics and interactive BOM available in the github https://github.com/spherical-sound-society/OPERA_ROTAS

You can watch additional videos and gather info in this thread: https://www.muffwiggler.com/forum/viewtopic.php?f=17&t=233199