moog kit build, makes sound but pitch is not right

Posted: 11/17/2009 10:47:36 PM

From: Texas

Joined: 11/17/2009

First off, I am a professional doublebassist, but I have played theremins many times. it is a great tool to work for any instrument, as the intangibility of it helps pitch. Anyways, I finally decided to buy my own theremin. I purchased the moog kit. I put it together, and it powers on and makes noise. When I am nowhere near the theremin, it produces a high pitch. It doesn't really start to react to pitch until about 1" away from the antenna. Volume, (and volume antenna), brightness, pitch, and waveform all seem to be working. The pitch does change a bit when I move closer, but doesn't start acting like a real theremin until about 1" away. Any suggestions? Maybe a ground problem?

Thanks in advance
Posted: 11/18/2009 1:45:26 AM

From: Colmar, France

Joined: 12/31/2007

1.) Did you put the wooden cover on it? It contains 9 heavy metal screws whose capacitance is important for correct operation. My Etherwave behaves a bit like yours when I remove the cover.

2.) Did you turn the Pitch knob fully counterclockwise? If not, do so.

3.) If the pitch knob is turned fully counterclockwise, at which distance does "reaction" start? How is the "reaction"? Does pitch then go up or down when you come closer to the antenna?

Posted: 11/18/2009 4:06:25 AM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

I agree with Thierry - it looks like a tuning problem.

Moog's main theremin wizard, Amos, recently posted his tuning technique on the moog theremin forum, here ( (Fifth posting down.) It may be helpful.
Posted: 11/18/2009 7:45:18 AM

From: Canada

Joined: 8/1/2008

It's been years since I've diddled with an Etherwave theremin. Do their circuit boards still have those little silver boxes with the adjustable screws for tuning the fixed and variable oscillators?

If they do, it is a good idea to drill three small holes in the lid of the instrument directly above each box so that the oscillators can be fine-tuned without having to remove the top. You can save yourself a lot of time by doing this.

It is very frustrating to tune the instrument only to discover that when you replace the lid it's all screwed up!

Posted: 11/18/2009 9:31:49 AM

From: Texas

Joined: 11/17/2009

Yes, case is on. There are only 4 screws that screw on the case, however.
2. Pitch knob is all the way to the left
3. When I am far away from it, or not even in the room, it still produces a rather high pitch. That pitch fluctuates as I get closer to it, but only minimally. When I get about an inch or so away from it, it gets into normal theremin range, but shoots up the entire range in that one inch. There is nothing within an inch grounding out the pitch knob, as I have tried it in different rooms with different amps.
Posted: 11/18/2009 11:35:03 AM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

[i]Pitch knob is all the way to the left[/i]

What happens when you stand facing the theremin with your right hand by your side and slowly turn the pitch knob to the right?

Doe the sound go down in pitch until it is very low and then become silent and then start to rise again? (If it does, I think I know what the problem is.)
Posted: 11/18/2009 12:44:50 PM

From: Escondido, CA

Joined: 2/6/2008

Hmm ... that's about what the Etherwave at the Museum of Making Music did for me. Maybe they should take some time to tune it?


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