I don't know the details of the Ondes Martenot but only the Trautonium and
Theremin.

From my knowledge the (original) Theremin always outputs a pure sine wave as
the audio signal is generated by the multiplication of two high frequency
sine waves which generates - among other things - a sine wave with a
frequency that is the difference of the to HF sine waves (other components
like a sine with the sum of the frequencies is out of the audible range).
Maybe recording the Theremin with a microphone (room reverb/formants) or
"unintentional" signal processing in the amplifier/speaker system (e.g.
distortion) causes the additional coloring.

Best wishes
Dieter Doepfer

> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com
> [mailto: Doepfer_a100@yahoogroups.com ]Im Auftrag von jalmari3
> Gesendet: Mittwoch, 15. November 2006 13:25
> An: Doepfer_a100@yahoogroups.com
> Betreff: 1 Theremin oscillator
>
>
> I think we need one!
>
> How to make a Theremin or Ondes Martenot sound Obviously, those
> instruments have their unique playing controls and Ondes Martenot
> also has those special speakers. Still, even their raw sound seems
> to be somewhat magical. I don't think it can be properly reproduced
> with standard analog synthesizer components.
>
> - It is often said, that Theremin sound resembles sine wave.
> However, for example the sound used by Clara Rockmore (often referred
> as the best ever Thereminist) is actually quite "earthly". And Ondes
> Martenot can even make a nasal or buzzy sound especially in the low
> register. Listen here:
> http://www.archive.org/details/Harada (track no 5 "Thermal
> Conductivity")
> http://www.cmusge.ch/recherche/zea/martenot.html (lots of different
> sounds)
>
> - The Theremin/Ondes Martenot timbre correlates with pitch. This is
> musically important and sounds different from the normal VCO+VCF
> application. It is explained here:
> http://www.paia.com/ProdArticles/thereton.htm
> Note the part: "Some listeners find the sound of the current crop [of
> Theremins] to be lacking in this kind of character"
>
> A "Doepfer Theremin (and Ondes Martenot) oscillator" might be very
> useful and musical. Think about the status value! :) - The Ondes
> Martenot is practically the only electronic instrument, which is
> used in symphony orchestra...
>
> The hypothetical module should have an adjustment for timbre and
> perhaps for timbre/pitch correlation too... What do you think
>
> Best regards
> Jari jokinen
>
>
>