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

I have ordered one. I hope to report my impressions of the instrument soon.

@GordonC, You're going to be impressed with the bass on that rig of yours. :)

Well I think you'll be well impressed with the LV-3 Gordon. By the way, those Nixie Clocks are superb. Russian cold war tube technology and what I like is the figure '8' actually looks like that digit displayed and not one cube on top of another like most digital style clocks.

I really can't understand why there are still thermally unstable theremins coming into market. A theremin builder should have systematically studied all existing models before starting his own development, just as a "classical" luthier would do during his apprentice time.

Thus he would have found that there are enough cheap ways either to prevent thermal drift (a) or to make thermal drift of both oscillators synchronous, so that the beat frequency remains the same (b):

- Using a Clapp-Gourriet oscillator design which keeps the tank inductor DC free and makes the resonant frequency independent from the transistor's junction capacitance because the latter tends to vary with the temperature. The one which Anthony Henk used as a variable pitch oscillator is so stable that he could even use an XTAL oscillator as the fixed pitch oscillator. (Method a)

- Using a common current mirror design which makes sure that both oscillators are always at the same working point, thus having both the same DC current through the transistors and the tank inductor as in the Moog Etherwave Pro. (Method b)

- Using a copper shield between both pitch oscillators and coupling the transistors thermally from both sides to it as in the tVox tour theremin. This makes not only sure that both oscillators are always at the same temperature and thus have the same operating point but it greatly prevents at the same time coupling between the oscillators which gives a better bass range. (Method b)

All three theremin models cited above have almost "instant on" characteristics, the settling time is below 1 minute and the impact of these carefully chosen design variants is great in terms of playability while the production costs will only rise by a few cents. 

LOL ;-)

I obviously dont have an artistic bone in my body! ;-)

All I see when I look at things like those clocks is a lot of expense and power and fragility..

The cold VF displays were / are really good - Lovely clear bright display - about 20 years ago I designed a lot of products which used them - But these parts then clocked in at only a little more than competing technology.. Some Futaba parts could be had for about £6 in quantity.. Now one is looking at about £60 for an equivalent VF display.. And a really good backlit LCD clocks in at about £6..

As for seperate Nixie tubes, I think one would need to be a real lover of tubes to find these attractive! - I suppose they have the abvantage that individual tubes can be replaced - But as each tube probably costs the same as a complete high-quality LCD display..

Not where I would be spending my money, even if I had any! ;-)

Fred.

"I really can't understand why there are still thermally unstable theremins coming into market. A theremin builder should have systematically studied all existing models before starting his own development, just as a "classical" luthier would do during his apprentice time." - Thierry

I would be really interested in your opinion of the thermal stability / "warm up" time of the EW, Thierry - It seems some people at least are having 15+ minutes before they are stable - Is this common?

I must admit that seeing the drift on the LV-3 did horrify me a bit - as you rightly say, there are lots of ways by which thermal effects can be reduced.. Some (not all) of these do add cost - so I am not too surprised that with low-end theremins, eliminating drift is not seen as a priority - At £100 retail for a full theremin, there are no margins if one wants to make any money - so even if there is a simple fix, the time required to find / implement a fix could make doing so unworthy of the effort in terms of commercial factors.

And, as you say "A theremin builder should have systematically studied all existing models before starting his own development" - But this takes time, time is money.. If one wants to make money, you reduce the time..

This, I think, is what seperates those who design theremins - and probably those who just knock a theremin together and put it to market, are the ones who make the money.. Those who spend the time as a "luthier apprentice" will, in this "industry" never recoup their costs..

Most people are happy with toys, the standards which we would deem minimum are too high, and if we try to recover our costs the price of our theremins are too high... Even without recovering our costs, to meet our minimum requirements our theremins will be more expensive than the toys - and most people wont notice, and buy the cheaper toys.

I suspect that the LV-3 will mop up a large chunk of the market, simply because the price is right - All other issues (linearity and thermal drift etc) really make no difference to most users.

Fred.

'I really can't understand why there are still thermally unstable theremins coming into market. A theremin builder should have systematically studied all existing models before starting his own development, just as a "classical" luthier would do during his apprentice time.'-Thierry

Maybe not the best analogy Thierry as modern luthiers continue to make fiddles in the same way as Amati and Stradavarius did 300 years ago.

It is true that some modern makers will perhaps utilise modern tools to make instruments but they will strive to make instruments having specifications very similar if not exactly the same as those of the classic master makers.

A few modern makers do try to vary the design and parameters of the instruments but the fiddle playing world is extremely conservative (with a small 'c') and do not embrace change readily.

That said, the traditional fiddle design as made by Strad is debatably as good as it can get so any 're-design' would be a retrograde step.

"A few modern makers do try to vary the design and parameters of the instruments but the fiddle playing world is extremely conservative (with a small 'c') and do not embrace change readily." - RoyP

The above is possibly truer for the theremin world.. At least with a fiddle, one could probably expect reasonable return if one built a close equivalent to a Stradavarius .. and there are enough fiddle players who would be interested even if the masters werent..

With theremins, the tiny market for instruments is fought over and dishonest competitors speak utter rubbish, (but the theremin playing public are hoodwinked)  and new ideas are castigated or de-valued ruthlessly.. I believe that the reason Bob Moog kept his "deviant" designs a secret was because he believed that even he / his sales would have been damaged if his new ideas came to light.

Its far safer to make a conventional theremin toy, or to make a high-end theremin but not disclose ones new ideas, than to play "open-hand". Honest disclosure gets you jumped on and pounded - the threat (anyone who deviates from convention) must be discredited at any cost.

Just to make it absolutely clear - I believe this reaction is natural.. One has "in the box" almost "mystical" ideas sometimes as a developer - you fall in love with your irrational beliefs. I have unjustly "slammed" theremins and ideas which didnt conform to the "mythology" - Its only since becoming a "heretic" that I can see this folly. Some theremin engineers / developers / producers have however been deliberately and wilfully dishonest in their dismissal of new ideas, and in their advertising.

"That said, the traditional fiddle design as made by Strad is debatably as good as it can get so any 're-design' would be a retrograde step."

I think this is the idea underpinning the thinking of some theremin purists.. "tubes" "large air coils" "analogue" "heterodyning" being seen as essential, and anything else being retrograde.

Is this true? Are Levs theremins "as good as it can get" ? I dont believe so, but even if it was so, part availability forces modern theremins to deviate from the original - If deviation is forced, IMO total redesign may be the only way to get to the standard of the original, or better.

I've only been involved in the world of the theremin for a relatively short time but in that time, from what I have seen and heard I think you are pretty much right in what you say Fred.

The fidle world has taken up a larger amount of my years and whilst what I have said about the fiddle as it is just now being as good as it can be, possibly being misunderstood to mean that I'm agin change, it is pretty much the case. There is nothing in the traditional fiddle which is in some way redundant nor there for a reason.

Of course I defer to those much more experienced than myself in the world of electronics to comment on the theremin.

'Is this true? Are Levs theremins "as good as it can get" ? I dont believe so, but even if it was so, part availability forces modern theremins to deviate from the original - If deviation is forced, IMO total redesign may be the only way to get to the standard of the original, or better.' - FredM

Even with my limited electronics experience but with experience in other areas I agree with this-the equivalent in fiddle making terms would be the advent of carbon fibre. e.g. With a carbon fibre fiddle it would be very difficult to include purfling but then again with carbon fibre plates there would be no need for purfling, and so on.

RoyP

The fiddle world has taken up a larger amount of my years and whilst what I have said about the fiddle as it is just now being as good as it can be, possibly being misunderstood to mean that I'm agin change, it is pretty much the case. There is nothing in the traditional fiddle which is in some way redundant nor there for a reason.

Traditional fiddle to me is not declaring all your income on your tax form to the UK government/IRS !!!!

Well, I have just done a sort of non scientific test and would say that the Moog Etherwave modified and LV-3 are about eight to ten minutes each to totally sort themselves out in my studio at this moment in time. Now that might be due to temperature stability/instability by me shutting the door (to reduce sound output into the house) and therefore raising the room temp with the theremins turned on, less airflow around the warmed-by-radiator room (test was done at 0.5*C external temp and 16*C in the room) plus my physical approx 1Kw production. Who Knows...............yes Fred, you'll baffle me I'm sure but go ahead anyway :)

It's nothing that turning the unit on, going and making a cup of tea/coffee and returning has cause to concern me.