Moog Theremini Owners

Posted: 10/19/2014 5:40:41 PM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as . ...................................

Joined: 12/7/2007

See for my reply to RS post.

I do not want to hijack this thread with a reply, as I believe RS hopes / intends.


Posted: 10/19/2014 8:37:05 PM
Gary Honis

From: Sugarloaf, PA

Joined: 10/17/2014

I plotted linearity curves for my Theremini using the original antenna and also for the larger $5 hollow chrome 20" antenna bought from my local hardware store.  The values used were from my earlier posted tests, when I moved my hand to change pitch near the base of both antennas.  Based on the results, I think I will use the 20" antenna from now on.  The linearity curves and a photo of my Theremini with the 20" chrome antenna installed are below.

Rich said "And I'd love to hear any of the music you Thereminiists come up with."

The first day I received my Theremini, I used it to make a soundtrack for a comet Youtube timelapse animation.  You can see the Youtube video HERE.  The soundtrack was done with the Theremini using its #10 preset "Ethereal". The louder descending effect you hear repeatedly later on was made with a Korg DW8000 synth.  That is one reason I bought the Theremini.  The astrophotography videos I post on Youtube need some type of spacey sounding soundtrack.  I was pleased with the sounds I was able to get out of the Theremini for the soundtrack on the first day I took it out of the box. 

Linearity Curves

Posted: 10/19/2014 8:42:35 PM
Gary Honis

From: Sugarloaf, PA

Joined: 10/17/2014

Here's a photo of the Theremini with 20" Chrome antenna installed.Theremini with 20" Antenna 

Posted: 10/19/2014 9:53:28 PM

From: Northern NJ, USA

Joined: 2/17/2012

"The linearity curves and a photo of my Theremini with the 20" chrome antenna installed are below."  -Gary Honis

Ironically, the default Excel graphing methods very often lead to misleading graphs when doing scientific or engineering work. 

- I've found that I need to use "XY (scatter)" for the graph type. 

- Either the frequency axis needs to be logarithmic, or I need to take the log base 2 of my frequency data. Humans experience frequency logarithmically, and log base 2 is neat because the integers correspond to octaves.  The Excel function is:

  =log(frequency in Hz, 2)

[EDIT] Very nice video!  I bet that was a lot of work!

Posted: 10/19/2014 10:18:32 PM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as . ...................................

Joined: 12/7/2007

Interesting plots, Gary -

I have drawn verticals for each octave 'marker' (110,220,440) so it can be clearly seen that 2 octaves are spanned from about ~30mm to ~220mm.. This is in probably the most linear area of an uncorrected theremin response, so selecting this zone and placing your required not span here is wise!

IMO, this area should be quite playable - but one can see that even in this optimum zone, the higher frequency / nearer antenna (220-440 Hz) zone (horizontal lines showing vertical distances between octaves) is shorter than the lower frequency/further from antenna (110-220 Hz) zone.. This will expand out, and if you had set the theremini for a span of say 50-60cm in order to fit more octaves, the apparent acceptable linearity shown in your chart would disappear completely.

But for 2 octaves, ~200mm in the zone you have shown, should be perfectly playable.

The major problem, the reason why the theremini is difficult / impossible to play, is not primarily due to non-linearity..It is due to the 100ms latency! - As Keven Kissinger said, in terms of use as a theremin, this is a "show stopper".

And yes, it can be seen that the longer antenna is improving near-field linearity a bit.. Dropping the lower horizontal yellow line to track the red trace would reduce the difference in vertical length of the two octaves a bit.. But I am not sure that this tiny improvement is really worth the effort.. It may be if it does anything to compress the far-field (I have my doubts that it would) which is not shown in your plot.


Oh, BTW - I listened to your comet track, and think that its perfect for the video, and a fine example of  use of the theremini for sound effects and pleasing musical background "sound-scape". This is where the theremini can excel, because anyone can create such sound-scapes with the theremini .. It is only when trying to play tunes, as you were doing in your first post, that the problem reveals itself! .. If your primary interest is the stuff you did on comet, the theremini could be ideal for you.

Posted: 10/19/2014 10:50:45 PM
Gary Honis

From: Sugarloaf, PA

Joined: 10/17/2014

Thanks Fred for the analysis of my data.  Yes the frequency data was from F2 to A4, just over two octaves.  

Thanks Dewster for the Excel advice.  I redid the curves using the "XY (scatter)" for the graph type and formatted the frequency axis to be logarithmic as you recommended, and the result is below:Curves with Log Frequency & XY Scatter Type

Posted: 10/19/2014 10:51:19 PM

From: Scotland

Joined: 9/27/2012

Hi Gary,

I totally agree with all that has been posted here...


I had a look at your comet video and have to say that the soundtrack is pretty cool, which goes to show that sounds from the Theremini do have a place in the soundscape of the enjoyable...  :-)


Posted: 10/19/2014 11:59:09 PM

From: züriCH

Joined: 3/15/2014


looks like the perfect instrument for you and your video soundtracks. slow and spheric. btw.:you probably have seen these posts already:

and i like your antenna tip.

may the starry knights be cloudless and with you

Posted: 10/20/2014 8:19:58 AM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

Peter wrote, "I would really like to do something creative and interesting on it - I'm just not sure what."

I have some thoughts on that. In all probability I'll be teaching my grandmother to suck eggs, but I'm darn well going to share my thoughts anyway!

A lot of the criticism of the theremini has focused on its limitations.

Limitations are not necessarily a bad thing, when it comes to creative endeavours. Paintings are limited by the edge of the canvas, haiku have a very restrictive format, classical musicians spend years learning the conventions of classical music and tend to observe them rigorously. 

The trick is getting the right amount of limitations. Too many, and you are too constrained in what you can achieve, too few and you get either chaos or writer's block.

This is one of the points made by Cage's 4'33" - it is the example of total limitation. Do Nothing. To ram home the point, he incorporated a joke into the composition - Do Nothing Three Times! It's a shame in a way that Cage didn't balance this with the composition at the other extreme - Do Anything. But I'm wandering off topic.

When it comes to the theremini (or indeed any instrument) three sets of limitations are at play. The conventions of any given musical style, the abilities of the musician and the restrictions imposed by the instrument itself. 

The big limitation of the theremini is the latency. This severely limits what the musician observing classical conventions can play on it - it's going to be pitchy, the timing is going to be sloppy, no matter what the musician's abilities. 

So the choice is to either throw out the instrument or to throw out the conventions. As you're determined to keep the instrument, it's time to throw out the conventions and replace them with a much simpler rule - Play What You Like. (By which I mean explore what the theremini is capable of in your hands, find out through this exploration what is pleasing to your ear and use that as your musical palette from which to create a composition.) 

As to the limitations of the theremini, here's the surprise news. Autotune mitigates some latency problems. Timing is still going to be a bit loose - finding the next note up or down in the scale by moving your hand towards or away from the pitch rod will always be a bit unpredictable, time-wise. But by gosh it will be in tune! Larger intervals will require a leap in the dark (unless you want to hit every note on the scale in between the start and end of the leap) but if you dial up a pentatonic scale you can be sure that whichever note you hit it will be acceptably consonant with the previous note. Not a very theremin-like approach, but the theremini isn't a theremin, so that's OK. (And it still has a theremin volume loop, so it still has half the magic!)

The theremini also loosens a significant restriction inherent in the theremin - it has a fair old number of timbres. More if you figure out how to access via MIDI the controls that aren't available on the front panel. Take advantage of them.

I think the reason that you're unsure what to do is that you're in unfamiliar territory. You know Classicalmusicland very well, where some interesting places are and how to get to them. But you've just parachuted into a foreign country without a map. Don't stand there complaining that you don't know where to go, pick an arbitrary direction and head of like you know what you're doing. And if that direction doesn't bear fruit, head off in another. I bet you'll find something good and probably not at all what you anticipated. 

(And if you really want a map, my favourite cartographer is Brian Eno - I was fortunate enough to buy a copy of More Dark Than Shark by Eno and Mills when it was still in print and I count it as a treasured possession. I see on that second hand paperback editions are available and a bit pricey but not absurdly so.)

Posted: 10/20/2014 12:27:07 PM

From: Canada

Joined: 8/1/2008

Gordon wrote: ".....This is one of the points made by Cage's 4'33" - it is the example of total limitation. Do Nothing. To ram home the point, he incorporated a joke into the composition - Do Nothing Three Times! "





A "specialist" is someone who knows more and more about less and less until he knows everything about nothing. ☺☺




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