Comparing two methods of creating the Theremin sound

Posted: 12/29/2015 9:43:01 PM

From: Atlanta Georgia

Joined: 12/28/2015

Have spent most of my time with robotics and am now intrigued by the theremin. Have spent a couple days reading all I can find about them and various methods of making them. I have a basic question - if two function generators, such as xr2206, were used to produce an output in the range of 0-3khz, would this waveform look different from one generated by a classic analog theremin circuit?

Posted: 12/29/2015 10:14:06 PM

From: Northern NJ, USA

Joined: 2/17/2012

I believe the mixed waveform depends mostly on the design of the mixer circuit itself.  

Also, function generators based on RC time constants might not be stable enough to properly do high frequency heterodyning.

The analog Theremin is fascinating in that such simple circuitry works as well as it does.  But the analog Theremin is at best a crude approximation of a linear (or exponential, depending on how you look at it or listen to it) capacitance sensor.

Posted: 12/29/2015 11:54:28 PM

From: 60 Miles North of San Diego, CA

Joined: 10/1/2014

SparkMaster said: “would this waveform look different from one generated by a classic analog theremin circuit?”

The magic word is classic, this could be interpreted differently by many.

I only know of one Classic Thereminist that has what I call the classic sound, it comes from the old, enhanced by the new. Some post processing can sound good as long it is not all reverb.

The theremin sound I like begins with the pitch oscillator wave shape. Not all sine waves are created equal and then single diode mixing, enhanced by follow up audio wave shaping circuitry.

I never found ideal frequencies to mix but 3 kHz is much to low to demonstrate anything.  Something between 100 kHz and 1 MHz would be a good place to start.

I wear a size 14 shoe,  I can walk all over those puny theremin whistles, but I would have to scrape them off my shoe. 0-'

My webpage reveals what I consider the ideal wave shape to use or enhance. The sound samples are theremin direct, no mic used.

Visit my old TW thread “Finding Clara’s Voice.”


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