An open-source DSP platform combines programmable hardware, an extensible SDK, and field-configurable interfaces to help developers create custom Eurorack instruments and effects.
Hermetic Modular has launched the Alchemy Lab, an open-source digital signal processing (DSP) platform for Eurorack synthesisers that enables users to develop and deploy custom audio algorithms. It is based on the Electrosmith Daisy module featuring an STM32H750 microcontroller.
The 12 HP, skiff-friendly module incorporates six potentiometers, three programmable buttons, the front-facing USB-C port with MIDI support, ten audio and control-voltage (CV) jacks and the rear microSD card reader. Six CV jacks can be configured as inputs or outputs through firmware, whereas the supports stereo audio input and output at up to 96 kHz/24 bit. The platform features a strip of 102 RGB LEDs for real-time parameter, modulation, and system status indication.
It is complemented with the Alchemy SDK open-source firmware framework published under the MIT licence. Based on libDaisy, the SDK supplies hardware abstraction, parameter locking, preset management, LED control and programmable CV routing so that developers can focus on implementing DSP algorithms while reusing common interface functions. The platform can also be expanded through rear SPI and I2C headers.
Two interchangeable firmware-based instruments are introduced in the form of Echoa and Spagyros by Alchemy Lab: Echoa is a stereo delay device with the ability to morph into reverb by employing diffusion techniques, while Spagyros is a multi-effects processor designed to enhance live performances through configurable effects chains. As a result of the same hardware platform, users can switch between instruments or install third-party firmware without replacing the physical module.
By combining open hardware with an extensible software framework, Alchemy Lab provides a flexible platform for DSP experimentation and Eurorack development.
