MOIRA - Norns Shield Euorack

MOIRA is an open sound computer redesigned specifically for Eurorack systems.

It brings the core experience of the norns shield directly into your modular rack—scripts, sampling, synthesis, looping, algorithmic rhythms, MIDI control, and deep interaction with your Eurorack system—all without requiring additional desktop hardware, external interfaces, or complicated signal routing.

Instead of placing a Raspberry Pi on your desk, MOIRA places a sound computer directly inside your patch.

More importantly, MOIRA is not a fixed-function module. It is a platform that can continuously change its identity. Today it may be a sampler; tomorrow a granular processor. The next time you power it on, it could become a looper, an algorithmic drum machine, a MIDI processor, or an experimental sound environment.
Designed for Eurorack from the Ground Up

MOIRA is not simply a norns shield mounted behind a Eurorack panel.

The electrical environment inside a Eurorack system is significantly more demanding than that of a desktop device. Power rails, grounding schemes, audio levels, and module-to-module interactions all introduce challenges that require dedicated hardware design.

To ensure stable operation within a ±12V Eurorack system while maintaining clean power and audio performance, we completely re-engineered the module's power architecture.

During development, we redesigned the power system three separate times and produced five PCB revisions. Every iteration focused on the same goals:

Reducing system noise
Minimizing digital interference
Improving audio dynamic range
Optimizing signal integrity
Allowing Raspberry Pi processing, MIDI, digital interfaces, power conversion, and analog audio circuitry to coexist reliably within a single Eurorack module

For an open sound computing platform, reliability is just as important as flexibility.

The current version of MOIRA is the result of extensive hardware validation, power testing, audio path optimization, and real-world patching sessions. Our goal was not simply to make it work, but to create a module that feels truly at home inside a Eurorack system and remains a valuable creative tool for years to come.
Audio Path Optimized for Modular Systems

Rather than connecting a standard desktop audio interface directly to Eurorack signals, MOIRA features dedicated analog input and output stages powered from the ±12V rails.

Both the input and output paths utilize custom analog op-amp circuitry with adjustable level controls, allowing precise gain matching across a wide variety of modular scenarios.

Whether you're processing hot oscillator signals, drum voices, feedback networks, or routing processed audio back into filters, VCAs, mixers, and external effects chains, MOIRA integrates naturally into the voltage environment of a Eurorack system.

The audio path is intentionally mono, reflecting the signal-flow philosophy commonly used in modular synthesis, feedback patching, and live performance environments.

Dedicated audio activity LEDs on both the input and output provide immediate visual feedback, allowing signal flow to be seen as well as heard.
Technical Specifications

Power

• Power Requirement: +12V 500mA, -12V 10mA

Mechanical

• Width: 20HP

• Panel: High-resolution UV-printed PCB panel

Audio Input:

• Mono

• ±12V analog op-amp input stage

• Adjustable input gain

Audio Output:

• Mono

• ±12V analog op-amp output stage

• Adjustable output level

Level Controls:

• Independent input and output potentiometers

• Optimized for Eurorack signal matching

Signal Indicators:

• Dedicated input and output LEDs

• LEDs respond dynamically to incoming and outgoing audio signals

MIDI

• 3.5mm TRS MIDI In

• Automatic Type A / Type B detection

• 3.5mm TRS MIDI Out

• Switchable Type A / Type B operation

USB

• 3 × USB ports

Processing Platform

Compatible with:

• Raspberry Pi 3B

• Raspberry Pi 4B

Storage

• Includes a pre-configured 32GB microSD card

• Operating system and software are pre-installed

• Ready to use immediately after inserting the card

Expansion

• Expansion header reserved for future CV-to-MIDI and MIDI-to-CV modules

• Expansion modules currently under development

Customization

• JLCEDA Pro panel design files provided

• Users can customize and manufacture their own front panels

Assembly

• Compatible with user-supplied Raspberry Pi 3B or 4B

• Self-assembly supported

• Assembly tools and resources provided

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