Questions about

Posted: 12/4/2015 10:29:03 AM

From: London, England

Joined: 1/27/2015

Hi all!

I read a bit about the project in this forum, where some theremin players found it very playable, and I have a couple of questions.

A few months ago I asked for advice about buying a theremini, but finally decided to save money for an EW plus. Unfortunately I couldn´t buy one yet, so, as I NEED a theremin :) I thought that the open.theremin could be a good starting point.


The main problem I find with the Theremini is its digital sound, I don´t like it compared to the rich and warm analog moog EW sound. But Open.theremin is digital aswell, isn´t it? So my question is:

I saw that has a CV/Gate out.  If I connect it to the Gate In in my Arturia Microbrute, could I control pitch an volume of my synth with the I mean if I would be able to play my Microbrute via the o.t.o

In moog forums someone says that you need two CV out and 1 Gate trigger to do this:

"by some reasons no one really understands, the theremini features only one cv output. you can feed that one by three different sources: note, pitch or volume. no gate. :cry:
to control the basics of a cv-synth, regarding you want to play it like a theremin with pitch&volume control, one needs 2cv out and a gate/trigger, to get the party started. this was done on the earlier etherwave plus theremin by moog. i'm playing my slimphatty with that, some adjustements, and it's awesome.
on the slim phatty one get's continuos gate on, drones galore, by pluging a jack into the gate socket. not sure if the Little Phatty does that too."


I ask this because I got a great theremin tone wit my microbrute (sorry to the purists :P) and if I could play with the o.t.o. my synth I would be happy enough till I can get a EW plus or even more, I would be happy with my open.theremin forever! :D

This is the sound I got with my brute, more ´real´ than the Theremini sound, I think (Artutia Microbrute is pure analog) and it could be modified to get a ´more realistic theremin sound´, I guess:



 Thank you!


Posted: 12/4/2015 12:55:51 PM

From: züriCH

Joined: 3/15/2014

hi werewolve,

with the .uno you can have one cv signal that goes from 0-4 volt. v/oct. you can use that for pitch or volume. no gate. info here: cv and midi instructions  . sounds like half of the sandwich to me, but with a sequencer you could get a gate function, arpeggios etc.  on a slimphatty you can make the gate constantly open, by plug a jack into the gate. not sure if the microbrute has that feature too.

whatsoever, if you like to get  control over your synth, you need more cv's. like on the ew+. (then you could replace that lfo-vibrato of the microbrute with a real hand-vibrato.) 

the audio/midi converter i2m musicport could be another way to control a software synth maybe. i think it's unbeatable in it's price range.

just my opinion: the uno v2 is good and fun to play with but the ew+ is the better solution for what you're up to.




Posted: 12/5/2015 12:44:58 AM

From: Northern NJ, USA

Joined: 7/29/2014

Nice thermein sound. What Microbrute settings did you use? I have one on order I plan on controlling from my Etherwave plus - so I'll post some stuff when I get it if you are interested.

I agree if you could cut out the constant LFO-like vibrato and control that through CV dynamically, you would get a much more realistic sound.



Posted: 12/5/2015 5:35:24 PM

From: London, England

Joined: 1/27/2015

#2 xtheremin8 Oh bad news for me :( The 'problem' is that if I bought an EW or an Etherwave Plus I didn't need to replicate a 'real theremin sound' with my Microbrute, so I didn't need 2CV outs or a Gate out :p

Maybe I try the just for playing a theremin till I can buy an EW :)

Thank you very much for your help!

#3 rkram53 Good choice Rich, you won't be disappointed with the MB, really good synth for its price, even with no memory presets or arpeggiator I'm really happy with it. Its sound is impressive.

You can find the patch image in my webpage:

You can control manually the LFO vibrato with LFO knobs in the MicroB to get a more realistic 'theremin experience' I didn't tried it as I am not a keyboard player and I was too focused on the right hand :D

I will be uploading more interesting sounds and patches for the Micro regularly and of course I would love to see an EW Plus and a Microbrute together in action!


Posted: 12/5/2015 9:39:01 PM

From: Northern NJ, USA

Joined: 7/29/2014

Hey Werewolfsound - thanks! I guess the software that comes with it lets you print out your current patch configuration - nice.

Looking forward to your patches. While it doesn't have an arpeggiator, the Microbrute does have a sequencer that can transpose based on the key you press. So you could program it to act like an arpeggiator and you get sequencer control - which I'm planning on using through the CV. From what I gather its a better choice over the Minibrute for someone who does a lot of CV work - and less expensive.


Posted: 12/5/2015 11:24:27 PM

From: London, England

Joined: 1/27/2015

Hi Rich, really good idea the arpeggiator trick! How didn't I even think about it! Maybe not for live improvisation but really useful.

About the software, I think you cannot print out your patches but users usually take pictures or you can use templates like the one I have in the description of my video. You can edit and save your own patches here:

Then you can capture the image from the screen and save it to your computer. Maybe you find an editor which alows you to save as a picture directly.


Posted: 12/9/2015 11:51:07 PM

From: Scotland

Joined: 9/27/2012

Hello all,

not wishing to hijack this thread but it mentions the Open Theremin and MIDI in the same place so it kind of is relevant to my query.
My question is really basic – I have an Open Theremin, what do I have to do to have it make sounds through my PC via USB MIDI?
I have visited the Open Theremin page and downloaded various programmes but do not know how I put them all together so that I can stand in front of the theremin and hear via the USB, MIDI sounds activated by the theremin.

Apologies for not getting it!


Posted: 12/10/2015 1:50:48 PM

From: Canada

Joined: 8/1/2008

The raw sound/timbre of this keyboard is not bad. The problem is, it its present form, it is soul-less because the notes are not individually “sculpted” and “shaped” to each note and musical phrase, the way they are on a theremin. 


A few years ago, I was talking to some people who were telling me about their impressions of the City of Venice and how charming it was and how much they enjoyed their visit. I asked them if they had toured the inside of the Doge’s Palace and seen the fabulous Tintoretto ceilings.


“Oh, we didn’t go to Italy. We didn't have to. We saw Venice at the Epcot Center in Orlando. It’s the same thing.”


For these good folks it really WAS the same thing, and there was nothing I could say to change their minds.

Posted: 12/11/2015 12:57:28 AM

From: Northern NJ, USA

Joined: 7/29/2014

I suggest you send an email to the contact list on the Open.Theremin site. Trying going to the horse's mouth. 

As for the theremin sound of the Microbrute. What I want to try is connecting up the Etherwave Plus and controlling a theremin patch with that. But I don't want to impose vibrato through an LFO and trigger an envelope with a gate. You will never approach the expression you can with a theremin that way. You want to remove the envelope and trigger the sound directly by connecting your CV input to volume response. Then control pitch dynamically through 1V/Octave CV. Thus you will create a very similar slow envelope as on the real theremin and be able to reproduce theremin vibrato.

In truth, if you have a CV controlled oscillator - you have the back end of the theremin right there. IMHO there is absolutely nothing special about the sound of a theremin's oscillator vs. an oscillator you can find on some analog synth if set correctly (not counting the older tube sound which I admit is harder to reproduce). Theorectially, you should be able to connect the Etherwave Plus to a CV controlled analog synth and create a sound that is virtually indistinguishable from a theremin that has a similar oscillator waveform internal to the instrument. This is an experiment I am working on with my modular - to try and get a variety of theremin sounds from the analog synth controlled by EW+ CV - so in effect I can have many theremin back ends from my EW+ (hopefully some that will approach the sound of some of the tube theremins I love hearing).

Here's a theremin challenge. Play a real theremin and then somehow (with gestural controller counts) play a synth and see if no one can tell which is which. I contend this is possible - especially with my playing.


Posted: 12/11/2015 3:41:13 AM

From: Northern NJ, USA

Joined: 7/29/2014

As an example (of the technique - not great playing) - and I want to test using my dropbox account here instead of using Soundcloud for sound examples -  compare the sound of this analog synth oscillator (just a triangle wave so a lot more could be done to try and emulate different theremin sounds) with the MicroBrute example (which I have to say I kind of like).

Here I am controlling the pitch using the Etherwave + CV pitch out going into the 1V/Octave CV input of the modular oscillator. Then I send the output of the oscillator to a VCA (voltage controlled amplifier). Instead of using an envelope generator on the sound which would give me the same ADSR profile for each note (unless I alter that dynamically somehow - which you can do on some synths), I feed the CV Volume out of the Etherwave + into the VCA's CV control and turn up the CV gain until I get to a max volume I like at full theremin volume. This way when I mute the theremin's volume, the VCA mutes as well and the envelope I create is based on how I use the volume antenna - as it would be on the theremin. The MicroBrute should be able to be controlled like this as well.

This creates a much more theremin-like sound that follows pitch in the right hand as it would on the theremin and volume in the left as it would. But you want to do something like this with MIDI - forget it!

Now I might want the MicroBrute theremin-like effect for some spaced out piece, but if the goal is to play an external synth expressively as if it was a theremin this is a more realistic approach. Of course you can now say - why bother - just use the theremin. But the theremin has a very limited sonic potential compared to my modular synthsizer where I can get all kinds of sounds - some very theremin like - others not.

So now lets go back to the Open.Theremin. I believe you can get a CV out on that. If not you certainly can add pins to get voltage outs programming the Arduino. So it could be feasible to create a Arduino-based gestural controller from the Open.Theremin design. But two CVs minimum are required to do much with CV (one of the Theremini's big flaws as a controller - if they had given us one more CV (hint, hint)  it would really have made a big difference). And at times its nice to actually have four CVs (for simultaneous Gate, pitch, volume and filter control). That MicroBrute actually has numerous CV ins and outs which makes it a wonderful CV interface.

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