Debian on a synthesizer

Bela is a low latency optimized platform for audio applications built using Debian and Xenomai, running on a BeagleBoard Black. I recently stumbled upon this platform while skimming through a modular synthesizer related forum. Bela has teamed up with the guys at Rebel Technologies to build a Bela based system in eurorack module format, called Salt. Luckily enough, I managed to secure a unit for my modular synthesizer.

Picture of the front panel of a Salt and Salt+ module

Inputs and Outputs

Salt features 2 audio (44.1kHz) in, 2 audio out, 8 analog (22kHz) in, 8 analog out, and a number of digital I/Os. And it also features a USB host port, which is what I need to connect a Braille display to it.

Accessible synthesizers

do not really exist. Complex devices like sequencers or basically anything with a elaborate menu structure are usually not usable by the blind. However, Bela, or more specifically, Salt, is actually a game changer. I was able to install brltty and libbrlapi-dev (and a number of C++ libraries I like to use) with just a simple apt invokation.

Programmable module

Salt is marketed as a programmable module. To make life easy for creative people, the Bela platform does provide integration for well-known audio processing systems like PureData, SuperCollider (and recently) Csound. This is great to get started. However, it also allows to write your own C++ applications. Which is what I am doing right now, since I want to implement full Braille integration. So the display of my synthesizer is going to be tactile!

A stable product

Bought in May 2018, Salt shipped with Debian Stretch preinstalled. This means I get to use GCC 6.4 (C++14). Nice to see stable ship in commercial products.


pepper is an obvious play on words. The goal for this project is to provide a Bela application for braille display users.

As a proof of concept, I already managed to successfully run a number of LV2 plugins via pepper on my Salt module. In the upcoming days, I hope I can manage to secure enough spare time to actually make more progress with this programming project.



Github Activity