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Updated 09.19.04

Ultermen 5 Potentiometer Settings

Pot 1-  Half Sine Wave Frequency Doubler, 3/4 clockwise

Pot 2 - Sine Wave or original input wave from your theremin, 3/4 clockwise

An angelic even-harmonic overtone sound occurs when Pot 2's sine wave LED is driving a little more intense while being complimented by Pot 1's LED even harmonic subtle output.

ult5angtest.mp3 (143k) This pitch begins at 800 hz with an even harmonic blending of LED 1 & LED 2, then
the LED 2 plain sine wave is play alone. See wave shape .gif's 7 & 8 below.

Pot 3 - Square Wave of your original wave. You could put a 1 uf capacitor across the LED to soften the square wave edge. Adjust the pot to compliment your need.

Pot 4 - Square Wave div/2, maximum clockwise
Pot 5 - Square Wave div/4, maximum clockwise

Pot 6 - Drives the input of the frequency doubler, don't over drive, 1/4 turn clockwise

Pot 7 - Original input from your theremin, don't over drive, 1/4 turn clockwise

To turn off an LED for certain sound effects put a opaque plastic cap over it.

All of the tests below are done with the Solar Cell positioned 13" from the output LEDs.

Download osc251.zip (89k) a desktop computer oscilloscope.

1-ult5good.gif - 400 hz -A good sine wave is when the peaks are pointed and not flattened.
2-ult5mic-od.gif  - 400 hz -Pot 7 needs to be turned down a bit. This sine wave signal has undesired peak clipping. Clipping also occurs if the signal into the microphone input of the sound card is overdriven.
5-ult5div2-good.gif - LED 4 div/2 square wave takes on this odd shape after passing through capacitors.
6-ult5angelic.gif - This is the ideal blending of LED 1 & LED 2 or the wave shapes  7& 8 below
7-ult5angdoubler.gif  800 hz doubled into 1600 hz.
8-ult5angsine.gif - A Perfect 800 hz sine wave from LED 2
The 5 voice technique currently used on the Ultermen 5 was chosen for it's circuit simplicity. As other
creative theremin thinkers explore possibilities these voices will evolve into something even better.