A curated directory of theremin schematics spanning multiple design approaches including tube-based, transistor, optical, and Arduino-powered implementations, ranging from beginner-friendly projects to advanced custom builds by notable designers.
A DIY tutorial for constructing a simplified Enigma machine from toilet paper tubes and cardboard, with step-by-step instructions to demonstrate rotor-based substitution cipher mechanics and historical context about Polish codebreaker Marian Rejewski's role in breaking the Nazi Enigma code in 1932.
Kyiv-based Sitka Instruments released the Gravity Eurorack clock module as open-source hardware under CERN-OHL-S and GPLv3 licenses, with Arduino-based design and alternative firmwares already available from the community.