Built Robert Moog's Etherwave Theremin

Posted: 5/19/2018 5:01:27 PM

Joined: 5/19/2018

Hello, I wanted to make a quick post about the Etherwave Theremin I built. This is based off of Robert Moog's DIY Guide
Thank you ThereminWorld.com for all your helpful building posts.

Here it is in action, I don't think I have it tuned correctly. Yes, the power supply is outside of the the Theremin, it already worked so I used it. In the future I will build the power supply into the theremin.

Here are some pictures:

It took 6 months total to build the Theremin, from ordering all of the components to getting them to produce a sound. To preface this project, I am relatively new to building electronics, and this was by far the largest circuit I have ever built. Therefore, take whatever advice I have with a grain of salt.

How I built the Theremin:
1) Ordered Components
2) Built the Antennas and Structure
3) Tested on Breadboard
4) Soldered to Veraboard
5) Tested

1)Ordered Components: Since the variable Inductors are obsolete. I did not actually use the Moog's Design, I used kostics design

The fixed Inductors  were hard to find for me, good luck on that. But for the capacitors, I checked what kostics had on his diagram and used materials specified in moogs design. All the resistors/bjts/ICs/capacitors were pretty easy to find, I used Digikey mostly.

2)Built Antennas and structure: I polyurethaned Sapele wood for the base, and I superglued a plexiglass case together. I was able to find all the copper bits and resin at lowes with no trouble.

3) Tested on Breadboard: I tested each oscillator on a breadboard to make sure I bought the right stuff. The oscillators were unstable, but proved that the components I bought oscillated at the correct frequencies. I had to use an oscilloscope to check this, I bought an analog o-scope for 25$ on craigslist. I recommend you pick one up if you are looking to build a Theremin. 

4) Finally soldered the entire thing to veraboard. Which required a lot of troubleshooting. I use fritzig to plan out the circuit board. 

Here are a couple links I found useful when building:

Moog's design and build instructions: https://www.cs.nmsu.edu/~rth/EMTheremin.pdf
A more up to date diagram: http://www.suonoelettronico.com/downloads/HotRodEtherwav.pdf
The model I used: http://www.thereminworld.com/Forums/T/31178/parts-clarification-for-etherwave-theremin-build
Volume antenna help: http://www.thereminworld.com/Forums/T/29255/etherwave-volume-dous-not-work
How the diff pair work: http://www.theremin.us/Circuit_Library/differentialpairosc.html

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