Close / Far Pitch Antennas?

Posted: 5/8/2012 11:32:33 AM

From: Northern NJ, USA

Joined: 2/17/2012

Theremins seem to vary quite a bit with the nearness of the pitch antenna to the player.  On the original "music desk" variety, the antenna is set more forward and therefore located farther away from the player's hand and body.  (It is also often higher, making it look a little like the player is conducting an orchestra - which may have been the intent?)  On the EWS and other modern models the antenna is usually located more or less the same distance away from the player as the volume antenna.

Because the physical operating range of the pitch section tends to be much broader than that of the volume, the earlier models strike me as more ergonomic.  But I'm wondering what people here think about this, particularly those who own or have some experience with both styles of Theremins.

Posted: 5/8/2012 1:19:38 PM

From: In between the Pitch and Volume hand ~ New England

Joined: 12/17/2010

Well, I end to play and feel better on my Subscope. It's a thin theremin and feel I can get closer to the pitch antenna without having to extend my arm too far as I would have to do when I play my Wavefront, which I dislike.... I am not tall nor have long arms, so anything helps for me :)

Posted: 5/8/2012 1:25:48 PM

From: A Coruña, Spain

Joined: 9/26/2010

Many thereminists seem to find it more natural to play the EW theremin not straightly facing the theremin, but at a slight angle towards one side. Maybe this has something to do with what you say, dewster? If your body looks slightly rightwards while playing, the pitch antenna will be slightly farther away from your body than the volume loop.

Posted: 5/8/2012 1:55:59 PM

From: In between the Pitch and Volume hand ~ New England

Joined: 12/17/2010

I don't know why, but I never can find a comfortable position for the volume antenna. It's ok, i manage without pain, but it would help if the antenna position would be in a different position than what it is now. not sure if lowe or higher would be better since i never experimented other than what it is now. 

Posted: 5/8/2012 2:25:14 PM
Thomas Grillo

From: Jackson Mississippi

Joined: 8/13/2006

Hi all. Regarding the location of the pitch and volume antennas. If I had my druthers, I prefer a theremin that has the pitch antenna well above the volume antenna by a few inches at least. Very much like the RCA and WF Classic, and EW Pro Theremins. The reason for this, is the extra few inches of vertical separation between the two antennas keeps the volume hand from intruding too far into the pitch antenna's feild.

Now, as long as your pitch hand is well between the volume hand and pitch rod during playing, you'll likely not have any problems with coupling issues. However, once your pitch hand is equal to, or greater than the distance the volume hand is from the pitch rod, the volume hand becomes the prime interacting component of the pitch feild, and will be able to affect changes of pitch as it rises up into the pitch feild during crascendo.

This "little" problem is rarely encountered. It's usually noticed when doing bass playing, and theremins such as the B3s, EW Standards, and any modle in which the volume antenna is equal to the level of the base of the pitch rod will exhibit this minor issue, and there's no way round it unless you build a custom cabinet that places the pitch rod well above level of the volume antenna.

Regarding the horizontal positioning of the pitch rod, I've noticed that it's much more comfortable, for me anyway, to have the pitch rod near the audience side corner of the theremin, but not too far. Any more forward, and I'd have to lean over to reach the pitch rod, and I'm certainly not as tall as coalport, so I'd still have a spot of difficulty even using Coalports method of stance at a floor model theremin like an RCA, WF Classic, or even my WF Travelcase. But I suppose I could adapt over time. ;)

From a standpoint of universal user interface architecture, the Subscope, B3 Deluxe / Pro are certainly there, because when turned round, the lay out is exactly mirrored. This makes it just as easy for a lefty to play as for a righty, well except for the fact the controls und up facing the audience in lefty mode. The EW Standard comes in a close second as the horizontal situational positioning of the pitch rod is only a couple of inches forward (toward the audience) in righty mode.

Oh, regarding the new version of the B3 Pro, and EW Standard, the volume antenna on these theremins can be flipped when switched round to lefty mode.

Posted: 5/8/2012 2:28:36 PM
RS Theremin

From: 60 mi. N of San Diego CA

Joined: 2/15/2005

dewster said: “Theremins seem to vary quite a bit with the nearness of the pitch antenna to the player.”

On my own theremin designs the nearness to the antenna is set by the player, this is as easy and variable as the pitch knob turns. Due to the design, perfect linearity will allow the pitch field to be 10” to 20” wide, the whole field is a sweet spot.  The real distance from the pitch antenna is determined by how many playable octaves are available on the upper end, even if never used.

I have always created my volume controls as stand alone so they can be placed anywhere, especially for bass playing, around the Thereminist at any height. Personally I like to stand sideways to the raised pitch antenna and have the volume on my opposite left side set much lower for my long arms, then use the adjustable volume shading (2" to 10") distance I enjoy. Also my volume response direction is reversible with a switch. Both controls of the theremin adapt to the artist, not the other way around. Easily play standing up or sitting down. Here in the states my theremin design is allowed to park and setup in the blue parking zones.

All this positioning is accomplished using two inexpensive 1/4-20 camera tripods for mounting a 3" x 8" pcb. Very transportable.

Sound Byte: bi-polar transistor - the buzz is deliberate for an early era effect. The highest note/freq ~1400 Hz  F6 is 6" from the pitch antenna. Raw, direct theremin to sound card.

What is disappointing about my well tuned EtherWave Standard is I must adjust it's pitch field to one width, the one that works best and suffer through the non-linearity. Notes outside of one octave are more of a premeditated guess for location with a quick finger readjustment for accuracy. This is probably why vibrato is so valuable and a natural characteristic of the theremin.

Theremins do not have to work this way and one day that chosen engineer will figure it all out and the community will stand amazed! The time is very near...  I am only a messenger and for most people what you have is all you have known so unfortunately you adapted, maybe to develop irreversible bad habits!

Bad habits reminds me of my Yamaha dirt bike back in 1970 which braked on the right side, then I got a BSA 441 from Europe which braked on the left side. In an emergency riding the BSA bad habits made me push down the shifter into a higher gear and what a disaster that was. Why is Europe backwards?

Posted: 5/9/2012 3:20:11 PM

From: Northern NJ, USA

Joined: 2/17/2012

Thank you for all the informative replies! You have helped me quite a bit with the direction I'm going.

My digital Theremin prototype is currently just a pitch antenna mounted on a 2" x 3" x 5" aluminum box containing the simple AFE circuitry (passives: one inductor and two capacitors with an additional four inductors in series within the antenna itself; actives: a single CD4011B for buffering & thresholding) hooked up to an old Xilinx Spartan 3 FPGA (field programmable gate array) demo board.  Pitch is somewhat cramped near the antenna and somewhat splayed out far away, but fairly linear over three or four octaves in the middle.  The DPLL (digital phase locked loop) in the FPGA is working quite smoothly with no dead or sticky spots, - this was the main engineering hurdle (famous last words).  Simple square wave output at the moment ("It's alive!").  Currently working on the logarithmic LED frequency display ("tuner") then plan to work on linearity correction and voicing.  I'm trying to avoid hardware multipliers in the logic so that I can target simpler / less expensive devices for the final design.

Physically my plan for the first prototype is to replace the top of a sheet music stand with a board cut to roughly same the dimensions (around 13" x 20").  The pitch AFE box & antenna will be mounted underneath the far right corner (with the antenna on a 90 degree UHF adapter) and the left hand controls will be at the near left corner.  By tilting the board and rotating the antenna back to vertical the player will be able to vary the distance to, and the height of, the pitch antenna as it relates to the left hand position.  An of course the overall height would be adjusted as normally.  Is that description clear or would a drawing help?

I anticipate the final design will be similar, but the board will be replaced with a shallow box, allowing all circuitry to go inside, along with small speaker(s) &  amp(s).  I hope to keep the top mostly clear so that it actually can be used as a music desk, with the LED tuner running horizontally along the edge closest to the player.

Posted: 5/9/2012 11:45:59 PM

From: germany, kiel

Joined: 5/10/2007

dewster - i guess you might have seen: DIS*PLAYER: Theory and Construction already. If not, ...

Posted: 5/10/2012 5:40:37 PM

From: Northern NJ, USA

Joined: 2/17/2012

"dewster - i guess you might have seen: DIS*PLAYER: Theory and Construction already. If not, ..."

I did stumble across that a month or so ago, thanks!  That's way more work to build than some logic in an FPGA, and almost certainly would not be as quick to respond.  I'm taking the integrated error from my PLL loop filter and driving an NCO for audio output - this same data can be low pass filtered and sent to a digital log2 and x3 circuit for direct pulse width modulated display with no calibration or drift issues.  I have it coded and hope to try this logic out in the next day or so. 

It would be a neat trick to incorporate this display into the linearity adjustment procedure, I'm still pondering that.  Doing it without dividers (or with divides that are 2^n shifts) is the issue, as is making the procedure simple and straightforward.

Posted: 5/10/2012 6:23:28 PM
RS Theremin

From: 60 mi. N of San Diego CA

Joined: 2/15/2005

Don Lancaster of Arizona told me over 20 years ago, if it uses more than three chips go with software.

Below is what I have used for 10 years and it is very fast using 1/10 of a sec sampling. An upgrade occurred in the past six months after chatting with William Steer. Without his program I never would have known true linearity was occurring. The UK does have talent!

351 kb actual size for Windows Tuner 1.3  Actual Screen Size, easily visible. Free!

Just set your sound card on "What you hear" and monitor your theremin. This is great for that first note but don't try watching as you play. The screen capture is my theremin sound in three flavors displayed in two dimensions.

Pictures and sound bytes add so much to a thread!

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