[PD] Re:[OT] How do your performance environments looks like?

[Chris McCormick]

On Sat, 19 Apr 2003 04:11:49 +0200
jose manuel berenguer <jmbeal at telefonica.net> wrote:

> coming back to Theremine again, even if not using the new MIDI 
> features, the frequency of audio signal could be analyzed by means of 
> fiddle~ and mapped to any other set of sonic dimensions. it is not 

If you are interested in pursuing this course of action, the following circuit is very simple & cheap to build. We have used this live several times, although I've never bothered to run it into [fiddle~]. It only uses two ICs and follows the same basic principle of the theremin, but using digital componentry (it doesn't produce the very nice sine-wave that a theremin does, but rather makes a horrible and harmonically rich screaming square type of sound wave).

http://mccormick.cx/gfx/digital%20theremin%20(small%20pic).jpg

I like the way the designer has used cheap hack with the hex-inverter to produce a square wave in the MHz range by feeding the hex output back into itself - ingenious! The capacitance detection and comparison to the original wave is done using a phase-locked-loop IC. Both of these ICs (or similar) are very commonly found in electronics stores. I find that it's useful to put a larger pot (such as 100k) in series next to the 10k resistor to provide a greater level of control, and to take you into realms of dissonance and self-modulation which the circuit was never meant to go to. Note that it does not include a volume control control component (only pitch).

Enjoy the screams,
Regards,

Chris.
_________________________________
chris at mccormick.cx
http://www.mccormick.cx
http://www.sciencegirlrecords.com