What you can build

Music

Analog-purist voices, digital grooveboxes, and hybrids.

Analog

No MCU. Voices, filters, envelopes, headphones.

Analog builders want gain as a current, not a multiply in firmware. This board is a guitar-or-synth voice with no MCU: a high-Z instrument jack, a split-rail LM13700 VCA, a panel pot for volume, and a real headphone amp. Describe the voice; Ohmni wires the analog chain.

music · analog

Analog synth

A complete analog voice with no firmware in the path: a triangle-and-square OTA oscillator, a voltage-controlled filter, an attack/release envelope from a gate jack, and an OTA VCA into headphones. Describe the voice; Ohmni wires the analog chain.

music · analog

Analog drums

Hats and snares start as noise, not as samples. This board is a gated analog drum: a transistor noise source into an OTA filter, an attack/release envelope from a gate jack, and an OTA VCA into headphones. No MCU. Describe the hit; Ohmni wires the analog chain.

Digital

MIDI, I2S, and firmware-owned sound.

music · digital

Pocket groovebox

Digital instruments live on I2S and MIDI, not on OTAs. This board is a USB-C ESP32 groovebox: TRS MIDI in and out, a stereo DAC into a real headphone amp, and a bank of panel pots on one ADC. Firmware owns the sound; Ohmni owns the hardware.

Hybrid

Guitar in, DAC in, one analog mix bus.

music · hybrid

Guitar + MIDI mixer

The interesting boards sit between analog and digital. This one takes a high-Z guitar jack and an I2S DAC, sums them on an analog mix bus, and drives headphones — MIDI in so the firmware can play along. Mid-rail analog is AC-coupled into the amp so the jack stays quiet.