NEW UK DESIGNED & BUILT THEREMIN with volume loop & pitch rod etc

"yes Fred, you'll baffle me I'm sure but go ahead anyway :)" - Chris

LOL - No, you have baffled me!

(as has Thierry a bit with his posting) - It gets to the point where one doesnt know what to believe with the stories one hears - More and more I realize that I can only trust what I have seen for my self - And with theremins, can I even trust that ?  LOL ;-)

1.) To me, getting the oscillators stable has never been the major problem - the problem has been the equalizing coil / circuit - I think the ferrite is probably a bigger contributor the thermal variation than anything else.

2.) I had a fairly detailed discussion with someone some years ago who I believed to be really "in the know" about the Henk theremins, and was told that the one problem which bugged Anthony Henk and his theremins more than any other was thermal drift - The implication (it might even have been said) was that this problem was a major factor in him abandoning the theremin

This person knew Anthony personally.. Like I say though, you never know in the theremin community whether one is hearing the truth.

3.) As I understand it, The T-Vox does not have an equalizing inductance.. So I wonder if this could be another reason for its stability?

4.) If equalizing inductance change due to temperature is a major factor (as I think it probably is) in theremin thermal drift, then the extra cost to fix this problem is not cents - these are probably the most expensive parts in a theremin.. Even good ferrites like the Hammond inductors are expensive - Air coils would probably double the cost of an EW.

But, as with all things theremin, we will probably never get any definitive answers - And it is probably a complete waste of effort to seek answers, as so few care as to make it pointless..

Herein lies the difference between a luthier and a theremin engineer - The luthier has hundreds of years of "the art" to refer to, with established theory and little nonsense. The theremin engineer has a few decades to look back on, and most of the information (even that of the "Stradavarius" which was wrongly detailed by those who first documented it) isnt worth the paper it was written on.

Add to this the mythology which has been deliberately created to promote the theremin as something it is not, and something it never could and never can be (starting right back with RCA's BS about it being a really easy - perhaps the easiest instrument to play) - combine this with the populations ignorance, and one has everything in place for confusion which can be exploited... Add a goddess and a "RCA switch" and you have the technical joke of the century!

Fred. 

Fred wrote: "More and more I realize that I can only trust what I have seen for my self - And with theremins, can I even trust that ?"

Yes, you can trust that, but only insofar as it applies to YOU because so much about theremins has to do with personal taste and preference. 

That is why I always advise people never to take any advice about theremins or theremin playing from anyone whose playing they do not admire, or have not heard.

I love the name that Maurice Martenot's biographer chose for his book: MAURICE MARTENOT, LUTHIER DE L'ELECTRONIQUE.

"Yes, you can trust that, but only insofar as it applies to YOU because so much about theremins has to do with personal taste and preference. " - Coalport

A valid comment, in terms of subjective matters - what one "likes" or "dislikes" in particular..

But from a "technical" perspective (as you often rightly declare with regard to pitch) a player is either "on key" or "of key" and the degree of "error" is measurable - How much such "error" bothers the player or listener, and whether this "error" ever imparts something "positive" would, as I see it, fall into "subjective" -

And this is where I sometimes have difficulty - Yes, I have my subjective preferences.. But my test instruments shouldnt have! ;-) .. Even if I dont notice drift (and I do) my data logger notices it, and tells me exactly what it "hears".. I may like (or not notice) a non-linear field, but when I have a lazer focussed on my hand measuring its distance from the antenna, and the pitch and distance data going into my data logger, I can see how linear the response really is..

Except that I cant.. because it seems that one fart is enough to change everything! - And this is one of the things I mean by "And with theremins, can I even trust that ?  LOL ;-)"

It is not possible in my remaining lifetime to evaluate every aspect of every theremin ever built - it may not even be possible to evaluate any of Lev's theremins comprehensively without getting my hands on one - and even with "hands on" unwrapping every aspect which makes its sound - every ancient capacitor and transformer and tube, not realistic .. Apart from which, even these theremins wont all sound the same or have the same response..

So we cannot use "what was" as a template from which to build todays instruments - We are not crafting violins, we are designing and building electronic instruments.. "Luthier" may have been applicable in the early days, when these instruments were new - but the idea is, I feel, taken too far if one talks about "qualifying" as a theremin "luthier" by studying prior instruments.. Maurice Martenot had no electronic violins or theremins to study - He may have been a Cellist, but what he worked with bore no reseblence to any acoustic instrument, and derived from his understanding of radio and heterodyning.

After discovering the series-resonant nature of the RCA tank, and seeing notes from engineers I most respected who missed this, and realizing that (in terms of copying the "Stradavarius") every theremin had gone in the "wrong" direction, I realised that I could no longer trust anything I read.. Many of my "explorations" started from stuff which came before, and I realised that my direction had been influenced by trusting the perceptions of others.. But whats far worse, is that I can now see mistakes I made, and some "understandings" I had were based on observations which could not possibly have been real..

Most disconcerting!

Fred.

Fred,

I fully can understand you. That's why I stopped a long time ago including things like "I've been told" into my considerations. And that's why I make any possible effort to put my hands on real instruments. 

My observations above result from the fact that the Henk prototype built for and optimized together with Lydia in 1993/1994 is actually in my hands (after almost 20 years it has several problems with oxydated potentiometers, broken solderings, capacitors which lost parts of their capacitance and so on). I can't naturally tell how other Henk theremins behave, but this one is really rock stable. BTW: It is more linear than the tVox tour (which I play most of the time since more than a year) although it has also no EQ inductors.

What I found out for me is that even if I think that I might have discovered the one or the other explanation for a specific behavior, I do not always trust the combination of my perception and my conclusions. But I note all that "for later" to see if I cross one day a different instrument which will either confirm or not my ideas.

Thierry.

Can see where you're coming from with the observations; especially the last paragraph.

I had a quick email conversation with the designer and these were his thoughts on 'his' LV-3 and the economics of production.

"It's always the way if you try to make something "affordable". You have to compromise here and there or your costs are too high and so few people buy; it's not worthwhile. The goal is to make the instrument good sounding, reliable, playable and add some unique features which I think we've done".

"But I note all that "for later" to see if I cross one day a different instrument which will either confirm or not my ideas." - Thierry

Probably a good idea.. Its not my way though - My "problem" is that I need to test my hypotheses (its just something I am almost always compelled to do if I have any doubt), so I deviate from my primary direction and get "hands on" testing ideas with simulation, and then with prototypes if the simulation doesnt show me an error in my thinking.. Waiting for something else someone else may / may not have done is not my usual way - Even if delusional, the only fun I get is when I think I have found or invented something a bit clever! ;-)

The only things I leave alone are observations for which I cannot see a mechanism or produce any hypothesis - Sadly, there have been a couple of  observations of this kind with theremins .. it is this that I find Most disconcerting!

But I know these "observations" are either themselves in error, or that I am missing something obvious - The most bothersome are the non-repeatable observations - I hate anything non-repeatable! ... What this sort of observation shouts out is "You have done something stupid!" - That either I made a mistake when I did the original experiment or observed it, or that (almost worse) that I failed to document something essential but un-noticed, and am unable to repeat the results because I am not exactly duplicating what was done before.

Its only a couple of such events in the last 5 years, but thats a couple too many!

Fred.

But I know these "observations" are either themselves in error, or that I am missing something obvious - The most bothersome are the non-repeatable observations - I hate anything non-repeatable! ... What this sort of observation shouts out is "You have done something stupid!" - That either I made a mistake when I did the original experiment or observed it, or that (almost worse) that I failed to document something essential but un-noticed, and am unable to repeat the results because I am not exactly duplicating what was done before.

Its only a couple of such events in the last 5 years, but thats a couple too many!

Fred.

Only twice? Good for you Fred! I must not have as methodical a mind as you, 'cause I can cock something up at least twice a year!!! Also, when I do duplicate a result that shouldn't be.......................it's because I made the same mistake twice!!!! Consistent & wrong  : )

It's an age thing.

"Only twice? Good for you Fred!" - Chris

LOL ;-) .. I think it comes down to the investment which follows the error which defines its significance - not talking about a wiring error or layout error or anything like that in everyday circuits (where mistakes and duplicating mistakes is common) - I am talking about exploratory investigations into fundamental operations - about making what must have been a flawed observation followed by flawed "understanding" to explain the observation, followed by spending a lot of time based on this.. And yes, that couple is a couple too many!

The trouble always comes when I have observations or hypotheses which I cannot verify in simulation..  Most things can be simulated - but some things (tubes, inductor equalizing etc) are difficult or even impossible without spending ages..

The other trouble comes when I fail to accurately document any and every change.. I then cannot know if my original observation was valid - but usually I must assume it wasnt, or at least that any hypothesis I had to explain the observation was wrong - because, if the hypothesis stands up, then even if the original test cannot be duplicated exactly, I should be able to create something similar by applying the hypothesis.. If I cannot do this, it is highly likely that the observation was faulty.

Fred.

"Only twice? Good for you Fred!" - Chris

LOL ;-) .. I think it comes down to the investment which follows the error which defines its significance - not talking about a wiring error or layout error or anything like that -

Im talking about making what must have been a flawed observation followed by flawed "understanding" to explain the observation, followed by spending a lot of time based on this.. And yes, that couple is a couple too many!

The trouble always comes when I have observations or hypotheses which I cannot verify in simulation..  Most things can be simulated - but some things (tubes, inductor equalizing etc) are difficult or even impossible without spending ages..

The other trouble comes when I fail to accurately document any and every change..

Fred.

 Ah yes. WRITE IT DOWN! Another thing I've learned over the years (and I'm not trying to lecture anyone here by the way) is to only make one change to something at a time, because if you make more than one change & it fails or succeeds you have no idea which change failed/worked!!!!

Well, I am now the happy owner of an LV3 Lost Volts theremin. :-)

I'll post my opinions in a while, when I have had chance to form some. (Other than BASS! WOW! - right down to infrasound. :-)

But for now, a quick comment, having met John - the maker. (Who incidentally visits TW from time to time, so feedback here will be appreciated. And, like so many theremin makers and players, he's a charming, smart guy.) 

The instrument is built to a price. He is aware of its imperfections, but feels there is insufficient demand for high-end instruments at premium prices. He is interested in developing capacitive controllers for MIDI, CV etc, but has a lot of projects on the go, so don't hold your breath.