Leon Theremin's Hidden tones...

The Moog Forum Theremin Forum
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Friends,

I want to share with you a discovery that I made, well I don’t necessarily claim that its my discovery because im sure that im not the only one that has discovered it.

I have an Etherwave Standard Theremin.

I read that Theremin was working on a way to get 2 pitches simeltaneously with his device, the second pitch coming from the left hand VOlume Antenna.

I don’t think that he ever truly developed it.


My discovery

I was running my theremin through an Electro Harmonix Bass Balls pedal. For those who don’t know its a twin dynamic filter for Bass Guitar. When turned on, especially on the overdrive setting where its mostly used, It truly boost the crap out of the theremins initial signal.

Heres how you find the sound:


WHat you do is you let it warm up as much as its going to and tune it in the traditional way of having your body standing outside of the field of capacitance.

There is a realm of sound hidden in the most extreme border regions just before you will hear the first click of the pitch oscilator. Thats where you want your right hand to be, right in the immediate outskirts of ALMOST activating the pitch Osc. Outside of this there is a silence, but as you approach this area it satarts to make a fuzzy sound.

Granted your goal is to put some headphones on with the volume boosted about as high as you can get it being extremely careful not to activate the oscilator as it will be painful to the ears. You want to boost the signal as much as possible with an amp or something.

Then what you do is you move your hand away from the volume antenna and listen close. You don’t want to activate the pitch oscilator. You shoudl hear a cracking or some feedback in the form of what sounds like a waveshape coming from the volume antenna.

Experiment with this and let me know if it is doing that on your theremin and if its not then what Ill do is I will get out my theremin and Ill do it and Ill give even more precise directions, as this is something that I just pulled from my memory.


This is the sounds that I believe Mr Theremin would have eventually developed, of someone hasn’t already. I think its having your left hand controlling the volume and the pitch of one wave and having your right hand control the pitch.


Let me know what you find out.

Eric

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Interesting discovery.

My understanding was Theremin initially had just a single pitch antenna for a number of years in the 1920s and then added the ability to adjust volume with an antenna.

I guess so long as the theremin circuit doesn’t interfere with another theremin, which I know can happen in close proximity, one could always just add another theremin for a second pitch. But if you are using both your hands then you have to use something else for volume or have no volume control.

One of the first things I tried when I got a pair of Doepfer Theremin Controller modules was to connect them to 2 VCOs and patch them through a ring modulator. By the way they just output control voltage, not audio waves so they can control anything that accepts control voltage like a VCO or a VCA, etc.

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I posted this same post on Theremin world and this is the response that I got:


Welcome to Theremin World, EricK. :slight_smile:

The volume loop does indeed produce a tone. That is how theremins work - the pitch rod is effectively part of a pitch-only theremin. The volume loop is part of what is effectively a pitch-only theremin too - except that the pitch from the volume loop theremin is converted to amplitude in the circuitry connecting it to the pitch rod theremin.

It truly boost the crap out of the theremins initial signal

…and when there is too strong a signal in the circuit it feeds back into the theremin and causes “ghost tones.” The easiest to detect is when feedback causes the tone of the pitch rod theremin to bleed through when the volume is muted. I do not have a pedal that powers up the signal as you describe, so I can’t reproduce your experiment, but I imagine a similar effect is happening.

The area of the pitch field that you describe is in the zero beat zone, when the pitch rod theremin is silent or at least sub-sonic, but before the zone where the etherwave’s auto-mute circuitry kicks in. (Without this, the theremin would growl at you if you walked away from it.)

It should be easy enough to tap into the volume circuitry and make it’s tone audible, but I wonder about it’s usefulness - a pitch that is locked to the volume sounds like a darned nuisance to me.

Little is known about Leon Theremin’s two tone theremin, but my understanding is that it did not operate as you describe, but rather created a secondary tone that was at a fixed interval from the primary tone, to create harmonies. It was switched on and off by a hand-held switch.

A similar effect can be achieved using a pitch-shifter. For an example of this using a Boss PS-5 “super-shifter” - with the optional expression pedal, which gives a means of varying the interval between the primary and secondary tones during performance - in an experimental context (you have been warned!) can be found in a piece I did called Butterflies Of Vertigo.

This was recorded in one take - no multi-tracking or overdubbing - just me, an etherwave, one pitch shifter and two delay boxes.

By way of contrast, In The Potting Shed features a fixed interval secondary pitch throughout. (The Devil’s Interval, or tritone - so it’s not exactly harmonious.)

(Oh, and please do be careful not to boost the crap out of your ears!)

:slight_smile:




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I don’t know if i agree with him 100% though. I seem to remember Theremin wanted to control 2 seperate pitches at the same time with one being from the VOL antenna.


Now I run my theremin through my MF-ring mod and the Electro Harmonix Bass Balls. I don’t use the bass balls alot but it is a twin dynamic filter and exactly like an envelope follower, the amplitude of the input signal will correspond with the level of the filter sweep. With the theremin you can essentially sweep the filter with your left hand. Its a neat effect but I don’t use it alot.

I also run the theremin through a delay thats built into my amp but I woudl really love to get it modified to put out Pitch and Volume CV’s so that when i get more synth modules, I can have greater use for the theremin than I currently do now. I don’t practice a lot fo in a song ill go halfway accompanying melody and halfway sci-fi noise hehehe.



Eric