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Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Repair Windows errors before they cause bigger problemsFix Now →EuroPi is an open-source Eurorack module that you can program to perform different control-voltage and gate tasks. Built around a Raspberry Pi Pico and MicroPython, it is a flexible platform rather than a fixed-purpose synth voice: its behavior depends on the script installed. Allen Synthesis publishes its hardware documentation, software, and build guidance, and says kits can be purchased directly from the project.
What can the EuroPi do?
EuroPi lets you write or install scripts that use its knobs, buttons, and incoming signals to control its outputs. That can make it a programmable utility or modulation source; there is no single immutable function that describes every setup. Allen Synthesis provides a MicroPython API, while community-contributed scripts offer ready-made behaviors to explore. See the EuroPi project repository and API documentation.
Out of the box, the behavior is determined by the firmware and script on the module. Check which script is installed and its requirements before expecting a particular function.
What are EuroPi’s controls and connections?
Allen Synthesis publishes the following specifications for the project. These are the project’s listed figures, not independent bench measurements.
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#1 Best Overall
- This simple passive mixer is suitable for mixing both audio and control voltage sources.
- Three channel inputs mix down to one output.
- It is not suitable for additive voltage applications.
- All the jacks are switched to ground to minimize external interference when not patched.
- Module screws included.
| Feature | Published specification |
|---|---|
| CV outputs | Six outputs, each 0–10 V, with an indicator LED |
| CV input | One 0–12 V input with 12-bit resolution |
| Digital input | One input for external clock or gate signals |
| Knobs and buttons | Two knobs with 12-bit resolution and two push buttons |
| Display | 128×32-pixel OLED |
| Expansion | Rear I²C header for added sensors or outputs |
The six CV outputs, CV input, and digital input make the published I/O primarily suited to control and modulation. The knobs, buttons, and display give scripts local controls and a way to present information. The rear I²C header is an expansion point; added devices require appropriate hardware and software support.
How do you program a EuroPi?
EuroPi software is written in MicroPython. Programming it means preparing the module according to the project’s instructions, then using or adapting a script through the documented firmware API. The project’s repository links to setup instructions and community scripts; the API documentation describes the available software interface.
Rank #2
- Ideal for beginners and modular synth gurus alike, Plaits promises a vast sonic palette that could find a home in any modular synthesizer setup.
- 8 Pitched Synthesis Models
- 8 Noise and Percussion Synthesis Models
- Width: 12HP Depth: 25mm
- Confirm the hardware. Identify the controller model and hardware revision in your build, then compare them with the current software configuration documentation.
- Prepare the firmware and script. Follow the project’s current programming instructions for setup and for installing or writing the script you intend to run.
- Calibrate the outputs. Use the project’s calibration instructions and choose the procedure that matches the voltage references you can provide.
- Check the script’s behavior in your rack. Confirm what it expects at its inputs and what voltage or gate behavior it produces before connecting other equipment.
Calibration references
The documentation describes a lower-accuracy calibration method using another Eurorack module or an external source that can provide 5 V or 10 V. Its higher-accuracy method calls for precise voltage references from 1 V through 10 V. These are calibration procedures specified by the project, not a guarantee of measured accuracy for every build.
Can you build a EuroPi yourself or buy one?
There are two routes: source the hardware and assemble a DIY build, or look for a kit or built module from Allen Synthesis if currently available. The repository publishes hardware materials and build documentation and says kits can be bought directly from Allen Synthesis. It does not establish current stock, kit contents, prices, or support terms, so verify those details with the seller before ordering.
Rank #3
- This is a "finish-it-yourself" kit. The surface mount parts are all pre-soldered, and the latest firmware is already installed. The panel and all other parts (including the Rogan knobs) for the circuit are included. You can swap our panel for another manufacturer's panel too! Assembly instructions are available on the Sound Study Modular website.
- TEXTURE SYNTHESIZER: Clouds is a granular audio processor that creates textures and soundscapes by combining multiple overlapping, delayed, transposed and enveloped segments of sound taken from an audio recording buffer.
- COMPREHENSIVE CONTROLS: Classic controls such as grain position, size, and pitch are provided. Clouds can superimpose up to 16 grains simultaneously and thus create thick textures. Control over texture density, independently of grain size, is thus provided. An external trigger input allows grains to be seeded in sync with LFOs or rhythmic generators.
- To provide a richer variety of timbres, Clouds allows the shape of the grain’s envelope to be morphed – from sharp rectangular edges to a smooth bell curve. In addition, a diffusion network can further dissolves the edges of grains into blurry textures.
- “Grain mesh” modes automatically adjust grain density, size, and the offset between successive grains in order to generate a continuous stream of audio that can be pitch-shifted / time-stretched in the manner of old-school samplers (or time-domain pitch/time processors).
| Route | What to weigh |
|---|---|
| DIY build | Assembly effort and required skills; sourcing components; matching the hardware revision to the instructions; and completing firmware setup and calibration. This route offers more scope to work directly with or modify the hardware. |
| Kit or built module | Check current availability, what is included, hardware revision, calibration and firmware status, and warranty or support terms. Those details depend on the current listing and are not established by the project repository alone. |
For a build or replacement controller, the configuration page lists Raspberry Pi Pico, Pico H, Pico W, Pico 2, and Pico 2W. Treat that list as the project’s stated selectable models, not as a guarantee that every model suits every hardware revision. Verify compatibility against the current instructions before sourcing a board.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Can EuroPi process audio?
The project FAQ says a community script has produced some audio, but cautions that accurate, full audio processing would likely require extra hardware. That does not establish EuroPi as a finished audio-effects processor or synthesizer voice. Whether a particular script can produce or process audio depends on its implementation and any additional hardware it uses. See the project FAQ.
Quick Recap
Best Value
- Amazing Dual VCA module from the 80’s
- Authentic reproduction of original “System 100M“ circuitry
- Each VCA features manual gain control and 2 audio outputs (low/high) with signal & clip indicators
- Linear/Exponential switch per VCA allows for increased flexibility
- 3-channel mixer per VCA allows independent mixing of all input signals
Rank #4
- 2x 1-to-3 passive multiplier or one 1-to-6 passive multiplier
- Input one cascades to all 6 output jacks, or can be interrupted by plugging a cable into input two.
- Width: 2HP
- Depth: 14mm
- Current draw: none!
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