Recreating a Theremin Sound "Outside the Box"

Posted: 12/17/2015 4:04:13 AM

From: Northern NJ, USA

Joined: 7/29/2014

Starting a thread for people interested in recreating the theremin sound and experimenting with analog synthesis, sampling, granular synthesis, etc in relation to theremin. I'll also start putting up some waveforms of my instruments to study. Likely will be a small audience. Be nice if we can all post waveforms here and collect a library of them - which will help recreate the sounds. And maybe help others build theremin sound sources.

Being an analog synth lover, from the first time I started playing the theremin I thought about what is so special about the sound? Now with the theremin, the method of playing is totally unique, as is the expressive potential due to the fluidity of pitch and to a lesser extent volume control but I contend that in this day and age, there is absolutely nothing that special about the sound of the theremin (from just a raw tonal perspective). If anything it is among the simplest of oscillator sounds when compared to today's plethora of analog sound sources (ok maybe not counting those magnificent old tube theremins). In fact, its two dimensional sound creates listening issues for me. Really nice to hear for a few minutes, but does anyone really want to hear two hours of the same theremin playing basically the same timbre with little harmonic motion (in the overtone sense). If you ask me, modern thereminists need greater sonic potential to keep an audience's interest.

What makes sense is a digital theremin that can create a multitude of sounds or a method where an analog sound source (i.e. a synthesizer) can be used in place of the internal theremin oscillator. Would be nice if you only had to buy one theremin but could make it sound like any theremin (the Holy Grail of theremin simulation). I assume more digital theremins will be coming soon.

My big issue: Not being the greatest thereminist, but wanting to compose for perhaps the most difficult instrument to play presents a challenge. I want to write pieces and create examples that are realisitc enough for a thereminist to get a good idea of how the piece might actually sound. Sometimes my playing is good enough for that, sometimes not. This presents two major problems:

1. Simulating an acceptable theremin sound

2. Creating a method of playing that sound which emulates the flexibility and nuance of a real theremin.

#1 is not so hard. Just play around with a triangle wave and some filtering and maybe a bit of modulation and perhaps fiddle a bit with envelope. Sooner or later you will find something that sounds like one or more of the theremins you know. In fact with a decent synthesizer there is no reason why you can not get a sound close to virtually every theremin you have ever heard.

Now sampling is another option but that's where #2 kills the deal. MIDI controlled samples have limitations, but I've used the SampleMoog Etherwave sample set effectively - though it still is quite lacking.

So how do we get a way of simulating the theremin expression and nuance? Well we can connect up the Etherwave Plus CV to the synth. But that is not helping the playing problem as you are simply replacing the internal oscillator with an external one and you still have to play the theremin just as you normally would (though you have just vastly opened up the sonic potential of the instrument). 

Using an LFO to create modulation is out. That's too fake and artificial as the modulation is too consistent (though maybe you could throw the modulation source through a random noise generator to model it better - I need to try that with a Wogglebug for those that know what that is). Using a mod wheel and keyboard is even more problematic. You can't get a natural vibrato and portamento that way.

Ah, but enter the Haken Continuum with CV control option. You can get a very nice and natural vibrato with the Continuum and it can create natural portamentos as well. It also has an extra dimension of control (Y axis) that can be used to add varying harmonic content - which may come in useful but will not really do much to help emulate a thermein which is more two dimensional in sound to begin with. I am experimenting with the Continuum's internal sound engine to recreate a theremin sound - and will report back on that later.

In the OPEN.Theremin thread we discussed using an Arturia MicroBrute to simulate a theremin. I just got a MicroBrute Analog synthesizer (monophonic) for modular control but I thought I'd experiment with it and the Continuum for a little bit. Hooked it up to the Continuum's CV gate and pitch, tuned the oscillator (there a knob for that) and then played around with a triangle wave with a bit for filter and resonance control and added a little overtone complexity to it (there is a knob for that). I got something that is very close to the Etherwave Sample library I have been using, only with the Continuum I can add a lot more natural control than I can with the sample library. And with the Continuum of course, I can easily play melodies. Interesting experiment. However I can't seem to figure out how to control the VCA like I can with a modular synth (where I will likely have more success recreating volume control). 

Here's a little sound clip. Need to experiment a bit more here. But lack of a way to control volume with Continuum Z Axis (finger pressure) may kill this deal - you can set the gate to trigger an VCA envelope but that may not be sufficient for theremin like volume response (which can be approached though VCA CV in control on the modular).

Arturia MicroBrute & Haken Continuum Theremin Simulation



Posted: 12/17/2015 1:52:30 PM

From: Canada

Joined: 8/1/2008

In the decades since the theremin was introduced in 1929, people have searched in vain for a simpler and more dependable interface that can take the guesswork out of producing that magical theremin sound. 


All these innovations have had one thing in common - they involve TOUCH. 


The theremin, on the other hand, is unique among musical instruments because touch is the very thing that is not involved with playing it - and this is what gives the instrument its ineffable and strangely human quality of soul. If you add the element of touch, the destruction of the very quality you are trying to reproduce, is guaranteed. You may end up with a viable sound that is the greatest thing since Jascha’s strad, but it won’t be a theremin or anything even close to it.


The definition of what constitutes a “theremin” has changed over the last twenty years, and now includes a huge variety of electronic sounds that emulate that spooky wobble familiar to fans of 50’s SciFi and horror flix. I have seen and heard dozens of so-called “theremin” performances that have been produced using all sorts of computer software, MIDI modules and what-have-you, and I have noticed something I find quite interesting.


As everyone here knows, I am no shrinking violet, and will not hesitate to say exactly what I think about a theremin performance. When I hear a recording that is billed as a theremin, but is clearly not a theremin, I usually post the following comment to the musician involved.


“Really loved the music, great composition, but that’s not a theremin.” 


The remark is not entirely sincere because I usually do NOT like the music but that’s beside the point. If you start by saying that, the person will be so angry they will probably just tell you to go fuck yourself. So I begin with a compliment and a little flattery. The reaction is always the same: “thanks…Y do u say it’s not a theremin?”


In any exchange that follows, the person usually expresses surprise that I could declare with absolute certainty that what I was hearing was not a true theremin but some kind of electronic simulation (something that anyone in this group of dedicated theremin fanatics could identify equally well). 


The ability of an emulation of any musical instrument to pass for the real McCoy depends on two things: the quality of the emulation itself, and the familiarity of the listener with the instrument being emulated. 


To put the shoe on the other foot, I once played a recording of a theremin emulation of a “walking bass” for a friend of mine who is a professional acoustic bass player, and asked him what he thought about it. 



He listened, and replied, “Please tell me you’re kidding!”

Posted: 12/17/2015 11:18:55 PM

From: Northern NJ, USA

Joined: 7/29/2014

Of course, my intent is not to say I'm using a theremin - just a theremin-like sound to allow me to better produce examples of my works for the instrument. And I think I can get a better sound with the Continuum playing CV analog sources now than I can with a sample library and MIDI manipulation.

But now the gauntlet has been thrown down and my new life's purpose is to create a faux-theremin performance that you think is a real theremin. 

By the way, is an Etherwave plus playing a Moog Synth through CV a theremin or not? We're already on a slippery slope there.



Posted: 12/18/2015 3:08:13 AM

From: Canada

Joined: 8/1/2008

rkram rote: “…….Of course, my intent is not to say I'm using a theremin - just a theremin-like sound…”


I think I see where we part ways (artistically speaking). You hear a “theremin-like sound” but I do not. I hear a sound that is light years away from anything even close to a theremin. 


There is no “right” or “wrong” here. This is a matter of personal taste and preference.


Create a faux-theremin that can fool me, and that takes the risk and guesswork out of playing the real thing, and I will follow you to the ends of the earth and you will never have to work again.

Posted: 12/18/2015 1:22:22 PM

From: Northern NJ, USA

Joined: 7/29/2014

Not working sounds really good - other than the fact it would take me all of my remaining time on earth to do this job, so that kind of defeats the purpose.

Even the Continuum is not totally continuous in pitch like the theremin. It's that dynamic pitch flexibility that sets the theremin apart from anything else I have ever heard - not the sound of the oscillator (except maybe for that Hoffman theremin you have that is totally unique to my ear). You have some issues with its sound. But I really love it. I'd love you to post a static waveform of that thing.

Posted: 12/18/2015 6:12:45 PM

From: Canada

Joined: 8/1/2008

With the Continuum, as with all other music-making devices I have ever seen or heard of, there is an INSTRUMENT. With the theremin, YOU are the instrument. 


As for the RCA, there is a hum that comes with the Radiola 106 speaker. According to the experts, this is inevitable but when the volume is up the hum is fairly unobtrusive. Apparently there is a way to get rid of it (something to do with chokes….). The trade off is a particular vintage sound that you can’t get with modern speakers.

Posted: 12/19/2015 4:54:25 PM

From: Northern NJ, USA

Joined: 7/29/2014

Well if I'm the instrument, I think it needs to go back to the shop for repairs!

I'll start posting the waveforms and spectral/FFT plots of all my theremins for those like me who are interested in the sound. I can't believe there is no library of waveforms of all the theremins out there for study. I think the way to do this is to just capture a static constant tone without vibrato to get a basis for comparison.

Posted: 12/19/2015 7:38:18 PM

From: Northern NJ, USA

Joined: 7/29/2014

OK. Downloaded an oscilloscope and spectral display (Spectrum Analyzer) program from the app store to run on my iphone - uses the iphone microphone so I'm recording this about three feet in front of the amp. I'm sure this is not as fine data as from a scope directly connected to the line out but it seems to do a decent job. For a similar comparison, I'm just placing a fixed object in front of the theremin to create a constant tone without vibrato.

Burns Pro

I'll start with my Burns Pro. You can't adjust the timbre - just volume, but frankly I like the more sine-like flutey, vocal character this instrument creates, especially in the higher register. In fact, I don't at all mind it with other instruments (here with a continuum string patch in the second example). My other theremins don't play so well with others as the Burns (though the Etherwave can be set to a similar sound). Still I really like the Burns, and it doesn't respond quite as quickly as the Etherwave - which in effect makes it feel like there is a bit of quantization on it and hence I find it the easiest theremin I have to play. I really like it. Will never get rid of it.

Let's look at the waveforms:

Here's one shot at about A=440 and an octave lower A=220 (note the sampling is different so they are not scaled visually as I think I had an autoscale on in one case). As expected there is not a lot of "edge sharpness" to it to create a buzzing sound.

Burns Pro Waveforms

Here's another go at around 500Hz with the accompanying FFT plot. Waveforms with the iphone shift around a bit and but the general shape is there in both sets. And the theremin sound is not totally static. But the Burns has very little of that "buzzing" theremin character some instruments have by nature or can be applied with tone/filtering dials.

Burns Pro 500Hz with FFT

The FFT is interesting. Basically from the 500Hz fundamental it, rolls off with descending amplitude every multiple of the fundamental (500Hz, 1000Hz, 1500Hz, 2000Hz, 2500Hz, etc). So we're seeing a waveform with even and odd harmonics descending in a rather proportional way through the first 7-8 overtones. The first overtone also appears to get stronger as the fundamental increases which can be seen in the 220Hz FFT below (though I need to do more samples to confirm this but this does seem to indicate that the harmonic content changes perceptibly as the tones get higher and of course it is a little more gutsy in the lower register). So The Burns has a sound that should be rather faithfully reproduced by a wave table constructed by adding the first 8 harmonics in an amplitude shape per the FFT. But the key thing is I want to compare this more sine-like tone with the theremins that produce a much more raspy/gutsy sound.

Burns A220FFT

For example, compare this to the wonderful sound "Old Temecula" achieves with his tube-based creation that tries to emulate "Clara's sound". That sharp edge there makes all the difference. I just love the sound he gets here. See the following thread:

Finding Clara's Voice

Christopher's "Clara's Voice"

Christopher - can you set this wave to a static fixed tone around 500Hz and post an FFT plot?



Posted: 12/21/2015 3:55:08 AM

From: Northern NJ, USA

Joined: 7/29/2014

Now lets look a bit at the Etherwave which has Waveform and Brightness controls so you can get a variety of sounds from the instrument from more sine-like to more gritty (this is not with Thierry's module). 

Etherwave Sine-like Setting

With all knobs left the Etherwave can get a mellow sine-like sound very similar to the Burns Pro - though the overtones appear to be much more pronounced on the Etherwave. Here we get a waveform and FFT very similar to the Burns though more overtones seem to be emphasized in the plot. This is even more evident when we dial up a grittier sound with the waveform and brightness knobs moving to the right.

Etherwave Plus All Left

So know I have to ask myself how might I recreate this kind of waveform if I want to use this kind of sound in a simulated theremin piece. Now I've been playing around with fixed oscillators to simulate the theremin but they have some issues in being a bit too static. For example this example using an Arturia Microbruet analog synthesizer (played with the Haken Continuum to get a more realistic vibrato).

Well its a bit too high to get a good feel for one and there isn't enough dynamic variation.

But now lets look at a much more sophisticated sound source - the Mutable Instruments Braids Eurorack module that can call up all kinds of sounds and many are using complex modeling techniques. They happen to have a vocal modeling patch (all patch can be controlled with a Color and Timbre knob so already we are getting into Moog Waveform and Brightness territory in terms of control). The patch in question uses a "combination of 3 oscillators arranged in a clever ring-modulation/hardsync patch to emulate formant synthesis – a technique named VOSIM and described by Kaegi and Tempelaars". Playing with the knobs I can recreate a waveform very much like the sine-like Etherwave and Burns sounds:

Braids VOSM

I can trigger this with the 1/V per octave output from the Continuum and send the output to a VCA and then control the output volume of that from the Z Continuum Axis (finger pressure). Also run through an Eventide stompbox delay/reverb. Of course I could have connected up the Etherwave Plus's CVs in the same manner. Now I can play the Continuum and get a result which I think is a lot more similar to the Etherwave. It have that more sine-like character but there is the element of a much richer harmonic structure like the Etherwave. Hopefully my Dropbox account is accessible.

So it may not fool all of the people all of the time, but its going to fool most of the people most of the time - and for my purposes of creating theremin mock ups for compositions, I think this is quite acceptable for this kind of theremin sound.

The nice thing is that I can dial up a very much more complicated sound and so next I want to take a look at some theremin sounds that have a much more complex harmonic content (we'll start with the Etherwave and then try and emulate those big old beasts). Now of course this discussion may well be of interest for the Open.Theremin community that can create their own wavetables.

Why am I doing this? Who the heck knows. It just interests me.






Posted: 12/21/2015 5:44:19 PM

Joined: 10/23/2014


If I understand Peter correctly, you are barking up the wrong tree in in searching for the "right" waveform.  Lydia, Carolina, and Peter all have instruments that sound different from each other, yet all sound like theremins. I believe that for Peter the thing that defines the theremin sound is the human quality of how the player transitions between notes, articulates the notes, etc.  It's like the difference between a drum box and a live drummer - the drum box is too precise and mechanical and sounds a bit artificial.

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