Open Theremin Project An Open Source DIY Theremin

open-thereminThe Open Theremin is an open source hardware and software project, with the aim is of building a next-generation, DIY theremin.

Two Open Theremin designs are available:

  • The Open.Theremin.UNO is a full Arduino-based theremin that offers both audio and control voltage outputs.
  • The Open.Theremin.RC is a more basic one-antenna (pitch) design.

The project is documented under a creative commons license.

Open.Theremin.UNO Features:

  • Pitch and volume antenna with excellent linearity and digital tuning
  • Arduino compatible shield for easy programming
  • 12bit digital to analog converter generates audio out signal
  • Waveform can be reprogrammed freely (stored in a look-up table)
  • Audio plug can be reprogrammed to provide Control Voltage (CV)
  • Connector for audio or control voltage on board
  • USB powered, no extra power supply required
  • Can be powered by battery
  • Low profile SMD design for simple shipment
  • Pads to screw or solder on antennas or antenna cable
  • One button interface
  • Distance of hand to antenna is converted to a digital value that can be used for other applications than theremins
  • Pads to connect analog potentiometer (or digital encoder)
  • Pads to connect grounding directly to board

Here’s a video of the Open.Theremin.Uno in action:

Here’s an example of a DIY Matryomin Matryoshka Doll Theremin, based on the Open Theremin:


The Open.Theremin.RC is a simple and basic theremin circuit with one pitch antenna.

The circuit will run on a 9V battery and produce a triangular output signal. The circuit is good to explore the basic theremin principle of heterodyne oscillators.

Kits for both theremin projects are available via the Open Theremin site.

One thought on “Open Theremin Project An Open Source DIY Theremin

  1. PAiA has sold theremin kits for years, not exactly cheap, but they make good stuff.

    Then Moog came out with that modern versions Etherwave and Theremini– I’m sure those are amazing as well.

    This seems like a very functional and versatile entry level version. The cost of an Arduino Uno is about 25 USD, and this shield (if you solder yourself) is about 54 USD. The option to use the antenna to generate CV or MIDI control data makes this a very appealing & flexible option.

    Makes a great gift!! Hint hint.

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