Glitchy goodness from an open-source granular synthesizer — April 6th, 2026 A granular synthesizer — or more appropriately, a granular audio processor — is a device that chops audio samples into small “grains” that are just a few milliseconds long. It then manipulates them and rearranges them, before outputting the result. The auditory effect is interesting and appealing to experimental artists, but even low-end granular synthesizers are pricey. So, Sid Rockett used an Arduino Nano R4 to build his own open-source granular synthesizer called Arena Digitalis. Granular synthesizers are expensive because they have to store audio samples, which takes memory, and then manipulate them in real-time, which requires processing power. Luckily, the Arduino Nano R4 ’s Renesas RA4M1 microcontroller has generous memory (32kB of RAM) and processing power (48MHz clock speed) at a low price. It also has analog input pins and a digital-to-analog converter (DAC).…