One day I will explain in detail on my Acoustics Effects webpage how I give a theremin voice character.
This would be an excellent and original webpage for someone else to develop.

(These are my personal notes while I develop this. Your ideas are always welcomed)

8/15/04 The Ultermen 5 etch-your-own PC Board is finished.

6/05/04 I finished the RS Theremin etch your own circuit board layout, it's time to layout the Ultermen board.

5/10/04 The Ultermen circuit board operates better with the LED's horizontal rather than vertical as show in the construction photo. Place the highest pitch LED to the left or outside position. This enables the volume control movement to be similar to the classic theremin by quieting when the hand moves downward (or upward) past the LED beam. The octaves are selected by moving left or right. (Volume adapts easily to the left- handed, right- handed, conventional or unconventional Thereminist.)

In the Angel.mp3  I covered the output of the div/2  #3 LED and used a specially designed Timbre circuit on the #2 LED. The voice nuances come from the multiple LED's and my  custom speaker acoustics which enhance the sound characteristics. This sound byte also uses a little reverb and no other externally processed effect. 

A .05 uf across the Malibu solar cell will soften the edge of the square wave from LED of the div/2 or div/4 output of the CD4013. This should be switch-able in/out at the preamp to select a warmer or sharper edge.

5/10/04 A diamond shape LED pattern may be more effective than the vertical column. Use a 2" x 2" x 2" x 2" spaced diamond. I haven't tried this Diamond shape yet.

Place this diamond shape pointing toward your inside volume arm elbow 12" to 15" from your hand.

Place the high tone at the top, timbre to the right, div/2 to the left and div/4 at the bottom. This way you can select any pitch without crossing over an unwanted tone.

The very sensitive Malibu solar cell is susceptible to 60 hz hum picked up from room lighting. Hand position relative to the room light may block this. Also you can use a solar cell that is less sensitive to frequencies below 100 Hz, this is preferable. I have this solar cell and it is 1" x 2.5"  and is the thickness of an aluminum soda can.

The finale design of the Ultermen Theremin Cello enclosure should allow the audience to clearly see your hands during play. In my living room I have found that using white gloves and a battery powered black light creates a mystical ambience. The battery powered black light does not cause the 60 hz hum interference. I purchased this black light in the hardware section of Savon's Drug Store for $20 USD.

To have gentle volume control, partially block the LED beams with your fingers. Let the solar cell rest freely in your hand with the cell side facing your fingers. The thumb is used to push the cell against your fingers for rapid volume cutoff. 

Set the initial theremin pitch to around 100 hz. This can be done easily by observing the lower div/4 LED. It will begin to flicker as it's output pulse rate drops below 30 hz where the human eye can see the flicker.