Oh, so many contradictory views - and I agree with them all :(
[i]"only one big knob which allows to vary the waveform from sine to triangle. That's it and that's enough for this instrument." - Thierry[/i]
[i]"Take the example of the Anthony Henk 1994 prototype. It has a more or less clean sine output and most of us would qualify this sound as uninteresting or even boring. But hear Lydia Kavina playing on it. Her ability to shape the tone with her hands makes it more interesting (in my ears) than any electronic device could ever do." - Thierry[/i]
[i]" Contrast this to the theremin, where no two notes are ever the same, and every note can be subtly shaded in skilled hands" - GordonC [/i]
I have only heard the Tvox played by Lydia, and it sounded unbelievably awesome - I have heard Lydia play a Gakken - and whilst not comparable to the Tvox, it still sounded impressive.. same is true for everything I have heard Lydia play - so it does not surprise me at all that she can instill 'awesomeness' into a pure sine wave..
But I cannot do this - I will never be able to do this - I doubt that even if I spent every waking moment practicing on a Tvox that I would be able to match what Lydia can do on a Gakken! ... and I think there are many Theremin players (the majority?) who need more control over tone in order to compensate somewhat for the fact that they are not Lydia or one of perhaps the top 10 players who can make a boring sound extremely interesting because they are damn good.
[i]"More knobs (or presets) allow perhaps more variation and combinations, but are they (musically) useful and so needed?" - Thierry[/i]
"(musically) useful" - the meaning of this will depend on who one talks to.. but sticking to classical Theremins for the moment.. Having a preset for each Theremin that has been popular (RCA, Moog, Tvox, perhaps even Theremax and Jaycar etc..) with a few knobs assigned to emulate the knobs of these instruments, would surely be desirable to a Thereminist, even if not strictly 'needed' - At present, if you want the tones available on a Tvox and perhaps some of the E-Pro presets, and a genuine RCA sound, you will be spending a lot of money and waiting a long time to acquire the instruments ... <<< PLEASE NOTE - This is hypothetical, and I AM NOT saying that I am designing an instrument capable of accurate emulation of every Theremin!!! >>>
[i]" think we will be falling back on the question if the theremin was to see as an individual instrument or as a synth-like device. - .. As an individual instrument it should rather have its individual and recognizable tonal character." Thierry[/i]
I would agree IF in order to achieve a tone pallet which included tones more usually found in 'synth-like' devices one got rid of the individual character of the Theremin - But I cannot see how expanding the tone palette would detract from a Theremin UNLESS the only sounds you could get would be 'synthesiser' sounds, and it became a "Synth with antenna".. This is the general CV route, but it is possible to make a "real" Theremin with voltage controlled modules - I understand there are a couple of Moog (Big Briar) Theremins that work in this way and do not use heterodyning (I would love to know more about these...)
I will probably regret blabbing this next bit, but it is so difficult to explain without playing "open hand"..What I am looking at is not primarily voltage control or analogue synthesizer technology in the normal way, it is complex pre-heterodyning wave shaping.. I have everything to do any wave shape on both the reference and variable oscillators.. All the wave-shaping parameters are voltage controlled, so (for each oscillator) there is a voltage to control shape mixing, a voltage to control pulse width, a voltage for filter cut-off, and voltage controlled modulation mixing to each of these ... I could have a knob for each of these voltages - this would be 18+ k