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RS Ultimate 2

This page has upgraded to the RS Illusion Theremin

Updated 03.07.05

This Ultimate 2  is a "true heterodyne theremin" as Lev Sergeivitch Termen discovered.
Build my Dual-Voice Theremin and use the photovoltaic (solar cell) volume control technique or use the "pitch only" line output. Lev experienced 1000's of frustrating hours searching for an effective volume control method.
Start this project by etching the circuit board and building the few components in the Green boxes of the circuit board graphic below. Then broadcast your theremin sound through a AM Radio for quick success. Add the rest of the components anytime later! 

The Radio Shack components with the etched board cost is about $50 usd

 
Over the Rainbow (211k) 
This is a Rapid Optical Volume Control demonstration using the hand held solar cell.

Every theremin voice "sound"  begins with the fundamental sine wave, then we re-shape it!

Audio Output - Sine Wave - .mp3 (208k) - 10hz- 2khz (Crank Up the Sub-Woofer & Hold On!)
(You could get this sound through an AM Radio only using the parts in the green boxes below!)

* Two Voice Real-Time Play *

Ultimate2.mp3 - (282k) or Ultimate2_3.mp3 -(272k)
 This demonstrates two voice LED pitch manipulation

The fluty sound above is the pure sine wave while the square wave timbre mix creates the whinny sound. A bit of  reverb from Nero is added.  I still can't play a tune but you will get the idea.

I designed a RS Pre-Amp board for the handheld Solar Cell and have a better design on the Postcard Hints & Tips webpage that filters out  the 50/60 hz hum from lighting.

Note: 12.26.04 This air coil design does not like being boxed in tight enclosures. The best enclosure is to mount your circuit board on the bottom of a thin piece of wood and drape a covering like cloth over the sides to conceal the coils. This keeps the board mounted pots accessible from the bottom. It is best not to have off board pots. Once set they have little need to be readjusted.

Warning: If you reverse the battery connection you will damage the TL082 chip! (-;

LED 1 & LED 2 are Red => 3000 mcd with a narrow 12 degree projection angle. Don't substitute!