TherAsynth - New product under development - What do YOU want?

Thanks Thierry - I have already used heat-shink on tubular antennas (direct galvanic connection with the metal of the antenna is a bad idea - so I use this as an insulator) - The fact that the parts are standard plumbing parts is not hidden by doing this.. But your idea of using colored heat shrink is a good one .. I have used clear shrink to date - fine for bright brass, but colour may add something and be better on copper!

FredM,
I knew Gordon would tell you the Truth.
If, you can truely bring your Theremin promises into reality, many more Humans shall embrace the freedom of expression of the Theremin as a musical instrument. Many people, lacking the inherent musical ability of the very few that play this instrument well, may have a better chance at playing in the 'Ether".
That would be my true emotional hope for your new Theremin.

Intellectually: 1)Pitch Rod and Volume Loop Control,(anyway with less cost but sturdy); 2)Straight Linearity; 3)Tuning Stability; 4)11 to 18 Inch Pitch Field; 5)Volume Loop Control Range 4 to 10 Inches; 6)True Volume Control to '0', (Volume Off); 7)Pitch Preview With Volume Control; 8)Midi Output,('Note-On' Protocol Implemented); 9)Control- Voltage Output,(1V/Oct); 10)Timbre Shaping,(Your Design); 11)Kit Option; 11)Assembled Option; 13)Case Option; 14)Deluxe Case Option; and 15)Wall-wart Power,(Mains Adapter), Supply.
Good Luck!

teslatheremin

FredM, I have three thoughts for you:

1) Yes, identifiable plumbing parts in the antenna would put me off. If I'm going to spend a bundle of money on an instrument, I want it to look attractive, not like something I ripped out of my basement ceiling.

2) Price, price, price. Compare your prospective price to other theremins on the market and make sure that you're confident that the features in your instrument justify its place in the lineup of prices. Remember that Moog's $5000 (US dollars) Ethervox only sold 48 units.

3) Modularity. Try to design your circuit as a set of modular pieces that you can combine in different ways on the board to create different models. That way, if for example you decide it's too expensive as desired, you could sell an instrument with your new sensors and not the modular synth, and then sell the synth as an add on, and also offer a different model where they're bundled together.

Best wishes, and please keep in touch with us.

I think it's important to keep in mind that production of this instrument may take a while to go from prototyping to high volume mass production.

I would expect prototypes, and early production models to use the common plumbing fixtures in the beginning, and I would not have a problem with this, so long as the end result was a fully functional instrument.

The K I S principal appies here for the time being. Keep It Simple.

Once it looks like high volume mass production is feasible, then I'd consider looking into the custom machined parts.

Also, it's important to keep in mind, that the Etherwave Standard uses antenna connections which featue the very stuff you can find at a hardware store. The PAIA theremax is evin simpler with antennas just a bit thicker than heavy coat hanger wire.

In my book "functionality" comes first, then form.

Thank you all again..

The antennas are coming along nicely – Combining readily available hardware (spent most of yesterday browsing electrical + plumbing trade suppliers, and finding bits I never knew existed!) – and closely examining other Theremins – and have put together a construction which is tidy and robust, looks a lot better and more stable than most of the other Theremins I have examined, and doesn’t look like a plumbers nightmare! – in fact, unless one examines closely, I don’t think the origin of these parts is obvious.

I have also been re-examining videos of professional Thereminists, and Thomas’s great tutorials and performances – and constructed the antennas to better suit playing techniques.

[b]One issue which concerned me was the SPACING of the antennas – I would really like some feedback on this..[/b]

It seems to me that the distance between antennas varies quite a lot from instrument to instrument, but that the Moog Pro (with its extension arm for the pitch antenna) looks like a comfortable arrangement.

I have designed my new antennas so that they both have a retractable horizontal extension tube which slides into the body of my instrument, the volume antenna is a plastic soft-sided box 8cm x 11cm (WxL), with a conical focused field and about 30cm range, and the pitch antenna is (in normal set-up) a conventional vertical brass antenna (brass tube 10mm diameter – length to be determined, but at present 25cm).

Each horizontal extension tube can extend 11cm – I could make this 22cm by offsetting the positions, but this would add complication and cost (and also make left-handed / right handed swapping more difficult)

The width of the box is 29cm, and with the bend radii etc taken into account, the minimum spacing between antennas is about 35cm, and the maximum spacing (both horizontal rods fully extended) about 55cm.. [b] Is this distance sufficient?[/b]

I have developed a focuser for the pitch antenna – this is a construction which simply clips onto the pitch antenna, and can be angled to give a 90 degree (+ fringing field – only the crudest of tests have been done at this time – but it certainly eliminates any capacitive interference from any object behind it) focused field

Antennas can be exchanged (they are simply gripped tightly by a gland on the horizontal bars, and when released, expose a miniature in-line plug and socket, which can be disconnected and reconnected to a different antenna – The plug also carries ‘information’ about the antenna ‘type’ – so exchanging the pitch and volume antennas will automatically cause re-assignment of the electronics – no need for a left-handed switch) and this allows fitting of the smaller field box antennas (with less distance range) to both sides for portable or desktop use.

There has been a down-side to the above.. The space occupied by mechanics to implement the new antenna scheme means that I cannot fit a full synthesizer into the first units (I will need to go to surface mount components to do that).. So I will be implementing a greatly scaled down version of the synth – perhaps only a couple of extra sonic features than what is found on other top range Theremins.. Still enough to class it as a TherAsynth, but not enough to boast Mini-Moog facilities.

[b]Thanks for the checklist, teslatheremin![/b]

1)Pitch Rod and Volume Loop Control,(anyway with less cost but sturdy); [b] Yes [/b]
2)Straight Linearity; [b] Yes [/b] Also adjustable to allow other profiles.
3)Tuning Stability; [b] Yes [/b] – Patent applied for new thermally insensitive multiple analogue exponential converter {Analogue Function Duplication, or AFD – The exponential converter is the main cause of tuning instability in voltage controlled music systems)
4)11 to 18 Inch Pitch Field; [b] Yes [/b] – being worked on
5)Volume Loop Control Range 4 to 10 Inches; [b] Yes [/b]
6)True Volume Control to '0', (Volume

The spacing between pitch, and volume antennas should be about 20 to 24 inches to accommodate the pitch field.

You'll want to have the volume antenna positioned a few inches below the lowest part of the pitch field so the volume hand can't interfere with the pitch field. ( I suspect the pitch field focuser may eliminate this problem. )

I'm assuming this could be done by the user by adjusting the volume support arm?

Thanks again, and keep up the great works!

Fred, sorry to drag on about linearity, but I've just reread the thread and I think I didn't quite make my point clearly enough.

As noted, players with non-linear theremins can compensate by moving their whole body into and out of the field to stretch out the high notes and compact the low notes, thus linearizing portions of the field as they play. (One advantage of this is that one can have a large playing area without having to play with one's arm at full stretch - fine control is easier with the hand near the body.)

BUT... it depends on the body being in the field. My question was - would this still work with your directional sensors, and would it still work if the body, hand and sensor are not in a line?

If the answer is no, then all a linearity knob would do for the majority of players is give them the option of making the instrument less playable, which would be silly.

An interesting alternative use for a knob that varies the way the theremin responds to intrusions into the pitch field would be have it vary between linear theremin and linear air harp. (By air-harp I mean pitch quantised - the "Cher Effect".) At the air-harp extreme end it would be an audible effect, at intermediate settings acting like bicycle stabilisers, subtly increasing the size of the sweet spots where notes are in tune. Training mode, if you like. (Or cheat mode, if you don't like.)

Hi [b]Gordon[/b] – [i]“An interesting alternative use for a knob that varies the way the theremin responds to intrusions into the pitch field”[/i] – This would be extremely difficult.. Few things are impossible – but this would probably be getting close!
The field focusing is quite a simple principle – I am simply screening off the direction that I do not want sensitive, by effectively placing a large ground capacitance in that orientation – ‘grounded’ objects falling within this ‘ground field’ have the same potential as the ‘ground field’ and are therefore capacitively ‘invisible’ – The reason why this works with my sensing system but would be difficult (but probably not impossible) to implement with a conventional Theremin is that an extremely large capacitance (compared to the capacitance of the player) is introduced, which is extremely difficult to compensate for if the antenna is directly driving the pitch oscillator. My system overcomes this because the effect of background capacitance is ‘computed away’ by the processor – leaving only the capacitance changes introduced by the player.

Watching some performances, I notice quite marked differences in the way players control pitch - In particular, I noticed that Lev Theremin seemed to play the pitch using only his hand – his arm tucked back, wheras Clara Rockmore seems to use position her arm in a way which I would think should contribute to the overall sensed capacitance – Other players seem to use their arms / bodies in various ways to increase or decrease sensed capacitance..

My new method of obtaining a directional field is a lot less focused than the former – the field shaper is now 90 degrees, so (if one ignores the fringing which will occur) by Pythagoras, the field (assuming both sides equal length) width will be the square root of the sum of the squares at the distance – cant be bothered doing the sums right now – they will only result in approximations anyway – but at about 8cm from the antenna, the field should be at least 16cm wide.

Unclipping the director will make the antenna omnidirectional (normal) – so having a linearity control would allow a player to set the response close to what they are used to, and in combination with the span control, it should be possible to do any kind of field distorting one can do with conventional Theremins… So I think the extra £2 cost to fit this feature is worth it.. If everyone prefers linearity, then I can leave it out at a later date – MUCH easier to take something out than to add something – specially in this core area.


Hi [b]Thomas[/b] -

[i]”The spacing between pitch, and volume antennas should be about 20 to 24 inches to accommodate the pitch field.”[/i] Phew! – got that a bit close! About 22” is my maximum extension with this present construction

[i]”You'll want to have the volume antenna positioned a few inches below the lowest part of the pitch field so the volume hand can't interfere with the pitch field. ( I suspect the pitch field focuser may eliminate this problem. )”[/i]
Yes – it should.. however, if the pitch antenna is used without a focuser, movement of the volume controlling hand could perhaps be detected by it – I want to keep all options covered!

[i]”I'm assuming this could be done by the user by adjusting the volume support arm?”[/i]
Yes – the volume antenna can be positioned below the pitch antenna.

I have made the volume antenna in my original sensor housing, as I do not think its range needs to be increased – and I think that having this antenna directional (to eliminate any effects from objects underneath it) is something people are going to want and never need to change – This simplifies antenna construction, as the traditional loop would be difficult to make directional – and also simplifies desktop / mobile use, as it can be oriented for these applications. I intend to supply an extra identical boxed antenna which would act as

[b] ANOTHER QUESTION ! [/b]

The sensor electronics is struggling a bit in dealing with the increased capacitances of the pitch antenna, particularly as it must automatically compensate for the massive increase in capacitance when the focuser is fitted - I am absolutely determined to have primary tuning fully automatic, so that the player never needs to worry about trimming anything an this area.

A solution is to change th processors I am using in the sensor electronics - this increases cost, but leaves a lot of spare processor pins and capacity to do other functions..

[b]The question is this..[/b] - If I was to add a small LCD, and implement a system wherebye [b]control[/b] of the sound generating section was done in a digital manner (Select the parameter, such as waveform, filter charactaristics etc from a [b]simple[/b] menu system,and edit this) would this put people off?

I personally love knobs one can freely twiddle, and shun digital access - but I am an analogue synthesist.. not primarily a Thereminist.. The advantage to digital parameter control is that the panel looks simpler and is not full of knobs, and that sound patches can be stored and recalled with ease.(Unit would be pre-loaded with preset patches which could be over-written.. Create a sound you like,and save it as a numbered preset.. Do people want the ability to give presets names? I would prefer not to have alpha/numeric character entry - I find this process laborious, and never use it - but would YOU want this?)

Presets would include a full range of Theremin 'emulations' so that those not wishing to get into the synthesiser (or those who have problems with their sight) would never need to.

The sound generators will still be entirely analogue, and primary user controls (things like antenna sensitivity, preview and volume level controls, etc) will still be standard knobs - it will only be the 'deeper' parameters of the sound generators etc which will be through digital access.

Implementing the above will offset the extra cost of the processors (it may actually end up being cheaper) and also provides a simple route to full MIDI implementation in the near future - (having a GUI already implemented, and all relevant signals and parameters available to the processors - the processors will be dealing directly with the antennas and user interface, so implementing a GOOD MIDI interface becomes a lot easier)
Do other people have my aversion / detestation of digital user interfaces? On this occasion I hope I am in the minority - a luddite stuck in the analogue past!

I have no issues with a digital interface, love the idea of being able to create and store patches, and don't care whether it's got an alphanumeric or purely numbered labelling system.