♾️ Ouroboros Loop Station

DIY 5-Track Audio Looper

Ouroboros is a DIY 5-track (Layers) stereo loop station designed for musicians, producers, and synth enthusiasts. Built on the Electrosmith Daisy Seed platform, it offers real-time looping with zero menu diving — just buttons and knobs.

Key Features

• 5 independent stereo tracks (33 seconds each at 48kHz)
• Real-time per-track control:
  • Speed: 0.3× to 2.0×
  • Pan: Left/Right positioning
  • Volume: Individual + Master
• Multi-input support: Guitar, Mic, Line
• Instant control — no menus, just hold button + turn knob

Audio I/O

• 🎸 Guitar (Hi-Z)
• 🎤 Microphone (with analog preamp)
• 🎧 Stereo Line In
• 🔊 Stereo Output

Hardware

• Daisy Seed (STM32H750 microcontroller)
• Through-hole components only — easy to solder and mod
• DIY-friendly design

Front Side:

Back Side:

Hardware

It’s free to use. If you build one and fancy buying me a pint, you can do so here:

Paypal

Ko-fi.com

Links

• Schematic: PDF
• PCB v1.1 (Tested): Gerber Files
• PCB v1.2 (Beta): Gerber Files
• BOM: Excel File
• 3D-printable enclosure: 3D Files
• Front Panel: Design Files

Firmware

Ready-to-flash firmware is available in the Firmware Master/ folder.

Flashing Instructions

Option 1: USB Mass Storage (Easiest)

1. Download the .bin file from Firmware Master
2. Put Daisy Seed in USB Mass Storage mode:
   • Hold BOOT button
   • While holding BOOT, press and release RESET
   • Release BOOT button
3. Daisy appears as USB drive on your computer
4. Drag and drop the .bin file to the USB drive
5. Firmware flashes automatically and Daisy restarts

Option 2: DFU Flashing

make program-dfu

Building from Source

make
# Creates main.bin in build/ folder

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Release notes v1.1 (important)

• IDC 16-pin ribbon. I planned to use a standard IDC ribbon to simplify assembly, but I mistakenly used a 1.27 mm pitch instead of 2.54 mm. You’ll either need a matching cable or to hand-wire the connection.
• The output is stereo. Always use a stereo (TRS) jack — a mono plug will short one side of the op-amp. I’ve added protection, but it’s still best to use TRS.
• Analogue and digital grounds are separated and tied at a single point. You must bridge them under the Daisy Seed before power-up. I left this open for easier debugging.
• This PCB does not fit standard Hammond aluminium boxes as-is. Potentially, you can abandon PCB for a socket and fit it with just wires. A 3D-printable enclosure is included.

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In progress — v1.2 (draft)

I’ve reworked the socket I/O board and corrected the IDC footprint. It should fit a larger Hammond enclosure. If anyone is willing to test the new PCB, you’re very welcome.

• V1.2 files: PCB Gerber Files
• Notes:
  • Socket / I-O board fully redesigned (new layout, different switch/jack footprints).
  • IDC 16-pin footprint corrected; please confirm the pitch before fabrication.

When time allows (between work and family), I plan to design a single-board version combining the Daisy and I/O section, properly sized for a Hammond enclosure.

Feel free to ask questions – always happy to help.

How to Use

Recording a Track

1. Select layer - Press any layer button (1-5)
2. Choose input - Press channel button to cycle: Guitar → Mic → Line
3. Record - Hold record button to start recording
4. Stop - Release record button to stop and start playback

Playback Control

• Play/Pause - Single click record button
• Clear track - Double click record button
• Volume - Turn individual layer volume knob
• Master volume - Turn master volume knob

Real-time Effects

• Speed control - Hold any layer button + turn speed knob
• Pan control - Hold any layer button + turn pan knob