Theremin as synthesiser controller

While I wait for my Etherwave Plus to arrive I've been thinking
more about the theremin as a synthesiser controller issues.

FredM's suggestion that I go the route of CV control of analouge synthesiser
is sound, except for one thing, there is no such thing as a cheap
analouge synth with CV/gate inputs. Even the oldest, least capable
devices are now retro cool and sell for big dollars.
(We won't talk about the fact that I sold a Roland TB303 for $100
back in the 90s when they are now selling for more like $1,000 LOL)
If I was more into DIY hardware maybe something from here:
Music From Outer Space (http://www.musicfromouterspace.com/)
would be cheap enough.

It's much cheaper emulate these type of sounds in digital hardware or
software, which brings me back to MIDI.
(I'll probably get lynched around here for saying something like that LOL)

I don't think the GM2 will get the job done, it only sends pitch bends
in the +/- 2 semitone range.
I believe MCV1a will track pitch via pitchbends over a larger range.

I think the MIDI protocol has enough flexibility to get the job done.
The problem is that there are no MIDI instruments (hardware or software)
that are designed to be played by a theremin controller.

If you created a virtual instrument that could control oscillator pitch
and amplitude directly via NRPN MIDI messages (NRPN so you can get 14 bit
precision) you might get some worthwhile results.
Perhaps you could also do some smarts in software to map this NRPN data
stream to note numbers and trigger notes/pitchbends when playing in a
staccato fashion or be able to switch to this mode via a foot switch.

What voltage range do the EW+ CV outs have? Most CV to MIDI devices
are restricted to 0 to 5v.

some
interesting CV MIDI gear (http://www.smartcontroller.com.au/instruments.html)
These controllers can map input voltages onto MIDI messages in
a fairly flexible way. Once you have the raw data in MIDI you
can do the rest in software, with a MIDI-OX script or the like
or directly in a custom VST instrument.

Greg O.

Hi again Greg, ;-)

You remind me a bit of a potential investor I had, who gave up on me when I refused to focus exclusively on MIDI "Theremins".. He just could not see my arguments!

Ok - my last pitch! ;-)

What is main attraction to MIDI ? well..
1.) You have a wide range of compatible instruments available.. Unless you want to use a Theremin as your controller - in which case you have none - and must make your own.
2.) You can interface to sequencers / PC's etc.

If sequencing / recording [b]MIDI[/b] data is what you are after, then you have no choice but to go for MIDI - And you need a MIDI 'replay' module compatible with the sort of stuff you want to do with the Theremin controller.

[i]There was a time, quite recently, where MIDI was a godsend for recording.. One did not have the facilities for quality multi-track audio recording / editing / processing one has today, even if you were extremely wealthy.. In those days I worked with a six track cassette Sansui "Porta Studio" (which cost me an absolute fortune - £600 !) and could record passages of 15 minutes max (cassette ran at 4x speed).. Without MIDI on my 8086 PC, I could not have done serious multitracking without bouncing..[/i]

Now, you can have almost unlimited audio tracks, you can do almost everything you can do with MIDI (editing, pitch shifting, quantization,effects etc)directly on your recorded audio - you really dont need MIDI.

So - Synthesizers.. No need for huge expenditure.. You need (minimum) a VCO and a VCA, and really a VCF. Even if you have no electronics expertise, you can build such a unit from available modules ..

Doepfer's Dark Energy (http://www.doepfer.de/Dark_Energy_e.htm) is a complete unit with far more than you would really need, and costs 398 Euro’s

The following system from Doepfer should give you an idea:

A132 Dual VCA 55 euro’s
A110 VCO 140 euro’s
A120 VCF 90 euro’s
A100 Mini case / PSU 75 euro’s

Total 360 Euros .. ok – probably best to go for Dark Energy!

Doepfer ar not (by a long way) the cheapest – and their “Theremin controller” is bloody awful! – but this gives you an idea about prices – and the [b]MOST[/b] you would need to pay to get a reasonable analogue synth.

... And as you have CV, there is no need to buy CV->MIDI, so deduct the cost of this, and the "cost" of the hassle that MIDI will cause you, and invest in analogue gear which will retain its value and do more justice to your Theremin!

Fred.

just been looking at available analogue synths.. Hmm.. Quite a lot of modular bits, but not many complete assemblies - and particularly not many (any) ideal for Theremins (oh - they will mostly all work with Theremins, but have things one doesnt really need..)

Dark Energy - Has MIDI and USB as well as CV inputs.. Useful - but you are paying for the MIDI / USB stuff.. and you dont need it for the Theremin..

Also - I think you may need a voltage shifter for the CV... You will need your Theremin to be playing a few octaves higher than The CV out..(3 octaves if you want the Synth to play 32Hz reliably).. and I dont think Dark Energy has the ability to transpose this far without a shifter or modification.

The "Music from outer space" SoundLab Synthesiser is a lot cheaper, and should be well suited - Find yourself a local Electronics hobbyist who can build it for you! ;-)

..

Hi FredM,

I'm not wedded to MIDI and I understand your arguments very well.
However it irks me to spend 398 Euro on a somewhat
limited single oscillator Dark Energy when I would rather use
the Cakewalk Z3TA+ soft synth that only cost me $20 US :)

If I could have a Mini Moog Voyager rack mount for 398 Euro it would
be a different matter LOL.

[i]"If I could have a Mini Moog Voyager rack mount for 398 Euro it would be a different matter LOL."[/i]

;-) .. Yes! I have this horrible feeling that by the time (if ever) I can buy a Moog "Old School" Synth, they will have gone the way of the E-pro!

Hi Greg,

I've just scanned the Cakewalk manual very quickly - it doesn't seem to have any means of getting an external audio signal into it. Which is a shame. It might be worth looking at PureData (or its commercial cousin Max/MSP) or maybe Reaktor or Bidule (I have not used these BTW - only trialled Max/MSP a while ago, but have heard good things of the others) which can accept and process an audio signal. I imagine there are others too.

Once the theremin sound is in your computer, all you need is an envelope follower to extract volume info, and a zero counter to extract pitch info. (The theremin waveform is simple enough that that is all that is required. It would probably work best with the continuous pitch preview from the etherwave plus. I also note that there is no need to track low frequency notes with the associated latency problems - just make the pitch field very large so that you only ever play high notes, then do some simple maths on the extracted pitch info to put it into the range you require before using it to drive an oscillator.)

Z3TA+ can be used as a VST effect and audio can be processed through it's filters and effects. It also has an envelope follower that can be used as a modulation source.

Oh, right. I missed that bit. So that puts you in a similar situation to me with my little modular synth on an iPod - plenty of ways to do interesting waveform shaping, certainly enough to keep me amused for a long while, but it would be nice to be able to do a software pitch to numerical value conversion.

My plan is to have fun doing the things I can do, whilst asking the developer to add the functionality I would like. :-)

FredM wrote:

If sequencing / recording MIDI data is what you are after, then you have no choice but to go for MIDI - And you need a MIDI 'replay' module compatible with the sort of stuff you want to do with the Theremin controller.

********************

The Moog MIDI Ethervox theremin will record to a MIDI sequencer but the only device that is capable of playing back what has been recorded is the MIDI Ethervox itself. Since the theremin does not send "note on/note off" commands to the sequencer, all that is recorded is volume and pitchbend data.

The advantage of recording the Ethervox to a sequencer is that the recorded data (pitch and volume) can be tweaked in any way the user wants. When used for playback, the Ethervox uses its VOICE TWO function which does not produce its sound through heterodyning. It is essentially a synthesizer that is indistinguishable from VOICE ONE (which is a traditional heterodyne theremin).

When Bob Moog was still working on the Ethervox prototype back in 1997, I asked him about the compatibility problems encountered when an Ethervox is used to trigger a MIDI receiver. How do you get rid of the "zipper effect"? Bob said that a special MIDI receiver would have to be built with automatic timed faders on each note so that as the pitchbend data stream was received by the MIDI module, the volume of each note would rise as the volume of its predecessor faded seamlessly. No single note would have to be pitchbent more than a whole tone.

Don't forget, even if a module were able to receive and play pitchbend data over 10 octaves, there is a huge difference in timbre between the sound of C6 when it is triggered independently, and C6 when it is played by pitchbending C3 up two octaves.

The problems with the MIDI Ethervox have nothing to do with the MIDI Ethervox. They have to do with the inability of MIDI receivers to interface efficiently with it and do what it tells them to do.

coalport writes:

[i]The problems with the MIDI Ethervox have nothing to do with the MIDI Ethervox. They have to do with the inability of MIDI receivers to interface efficiently with it and do what it tells them to do.[/i]

Yes. Now to create a MIDI receiver in software
that will do what it is told. A more practical
idea than than hoping for some new hardware to
be created specially for theremins.