Hi Dewster,
I swing between utter frustration (and sometimes contempt) at the matters you raise, and a curiosity about whats really underpinning the "mysteries". To me, there are mysteries - The Tvox highlights one of these, and actually makes the whole issue of "ideal linearity" even more mysterious.. If I had never played with (I wont say on ;-) a Tvox, I would probably be thinking it was all subjective BS - that the only reason folks believed it was great was because Lydia (who could play anything, except probably a theremini ;-) had made it her primary instrument.
But having played with the Tvox, I know it was by far the most comfortable instrument I have ever played - I was quite new to the theremin when I first played it, but compared to every other theremin I had played before and every one I have played since, it was, for ME, hugely more 'fluid' and controllable and 'natural' and playable than any other - and this feeling has been confirmed every subsequent time I played it... In Lydia's classes, when I couldn't hog the Tvox, I couldn't play! - The E-Pro was playable in the bass registers, but no where near as nice for me as the Tvox, I never got on with the EW (I found Gordon's Enkelaar more playable) - (must admit though that after about a month of fiddling with the EW board and doing modifications, its starting to feel ok to me now)
I assumed the Tvox was the most linear because I found it easiest to play.. Couldn't understand why I found the EW so bad when I knew it had better linearity than the Enkelaar...
So I am back at square one - Something makes the Tvox (for me) great - and if its not linearity (whether linear in the musical / mathematical sense, or linear as in some curve that makes it comfortable and playable to me) then what is it?
In experimenting, I have found that linearity does seem to make theremins more playable, and certainly gross non-linearity makes them unplayable - but there's something more to it I think .. I dont know what this something is, and worse, if I find this "something" to suit me, dont know if it would suit anyone else!
Which is one reason I have been pursuing user adjustable 'linearity' control, or perhaps several user presets to allow curve shaping.
"t's the endless thicket of mysterious circuitry with associated (reported / subjective) holy grail performance that makes Theremin research so needlessly difficult (and, conveniently for sellers, sustains unreasonably high prices in the used market - and, conveniently for buyers, sustains unreasonably high levels of ownership status). " - Dewster
Yes, it does do all of those unfortunate things - and some (much?) of the above is probably BS - but given the state of the art, its no surprise. If, like me, you find ONE theremin that suits you (regardless of whether others find the same or not) and you can only get this theremin on the second hand market at an high price, you have no choice. I would never (other than to examine and re-sell) buy an E-Pro, but based on personal experience, if I saw myself as aspiring to theremin mastery, I would do anything possible to own a Tvox.
As an engineer / theremin developer, I want to know WHY I love the "feel" of the Tvox - and why others love their Epro or whatever .. If I knew this and was able to give a new theremin whatever 'feel' the player wanted, that would be one big step forward ( sound is the other big step IMO).
But I am not sure that the answers will be available purely from looking at schematics and doing the kind of analysis available to us on simulators - Oh, the more information we can acquire the better, but I think it probably comes down to the physics and biology and neurology of the player as to what their ideal theremin is than can be derived from analysis of the theremin.
(I suppose the above sort of makes sense if we stop thinking about the theremin as the box with antennas on it, and think about it as a circuit encompassing a complex changing 'control' capacitor - the performance of this circuit will almost entirely depend on the nature of this capacitor - one circuit may be better suited to one particular complex capacitor and another to a differently constructed complex capacitor.. the players are all differently constructed complex capacitors and sure - we can design the circuit to best cater for the 'mean' performance of these capacitors, but such a circuit may not be optimum for any specific complex capacitor..
Make a circuit which can be adjusted by the complex capacitor so that it performs in an optimum way for them, and one then only has the issue of whether the sound coming out is optimum for the requirements - Make this sound adequately adjustable, and you may have an ideal theremin for everyone! )
And if / when that happens, then things change.. Then one doesn't need to buy some second hand theremin and obtain a mortgage to fund it just because you want something that suits your requirements - you can still buy these for "ownership status" and prices will probably remain high for this reason - but you wont need to.
Fred.
(I am at least an extremely complex capacitor - I condense, therefore I am ;-)
condenser - another (old) name for capacitor