Raspberry Pi Real-Time Audio Mixer

A custom Linux distribution for Raspberry Pi 4B (8GB) that turns it into a professional digital mixer with VST/LV2 plugin support, touchscreen UI, web/mobile control, MIDI, recording, and streaming.

Quick Links

Build-Instructions — Build your own SD/USB/NVMe image from source
Audio-Stack-Configuration — JACK2, ALSA, PREEMPT_RT kernel tuning reference
Hardware-Reference — Tested USB audio interfaces, NVMe HATs, displays, MIDI controllers
API-Reference — REST, WebSocket, and OSC API documentation

Features

Low-latency audio — PREEMPT_RT kernel + JACK2, 5-8ms round-trip at 48kHz/128 samples
Multi-channel routing — 16-18 channels to USB audio interface
Plugin host — Carla with LV2, VST3, Neural Amp Modeler support
Touchscreen UI — Kivy-based local display (5-7 inch)
Web app — Mobile-responsive mixer surface
MIDI control — Learn mode, clock sync, HID discovery
Recording — Multi-track WAV with session management
Streaming — GStreamer H.264 audio/video pipeline

Boot Options

The same image supports three boot targets. See Build-Instructions for flash commands and EEPROM configuration.

Media	Build Flag	Performance	Reliability
SD Card	`--target sd` (default)	Good — SDIO bus, some latency variation	Moderate — limited write endurance
USB SSD	`--target usb`	Good — shares USB with audio interface	Medium — test for xruns
NVMe HAT	`--target nvme`	Best — PCIe 2.0 x1 dedicated bus	Best — no bus contention