Ref: Silicon Chip Magazine January 2018
Originally invented in 1919 using valve technology, and as featured on the soundtrack for the 1951 film "The Day the Earth Stood Still", the all "new" completely transistorised Theremin will give you a truly retro sound. This new model is easier to build than ever with the volume plate incorporated into the circuit board. Also, most components, the switch, the pot and the power socket are mounted on the circuit board to eliminate messy wiring; the use of on board voltage regulation to suit a 9V AC power supply eliminates the noise that results from modern switch mode power supplies; and it can also be powered by an external 12 volt battery. We'll be honest, it is tricky to play and generally suits someone experienced with string instruments like a violin (Leon Theremin himself was a cello player), but with a little practice you can play some basic tunes, or just use it to make eerie sci-fi sound effects.