Multi Phase Stereo Waveform Animator. www.haraldswerk.de

Motivation

Multi Phase Stereo Waveform Animator front view.

This is my second take on a multi phase waveform animator as described in EN#87 pg.3 ff by Bernie Hutchins. This time in stereo. This module takes a single sawtooth waveform (and others as well) and then uses nine phase shifters for each left and right channel to provide moving shifts from 0° to 360°. These shifts are controlled each by an independent oscillator which operates on a frequency of about 0.01Hz to 1.0Hz. The nine shifted waveforms are then mixed back together, along with original, to a composite sound for left and right channel. The volume of all phase shifted waveforms and the original are controlled with potentiometers. So you can dial in any amount of animation you like. You can choose from a variety of frequencies for the phase shifters. The method used here is described in EN#40 by Ralph Burhans. Ralph found that if you space frequencies at the fifth root of 2.1, you get no harmonic overlap over a 10 octave range. This is important because we don't want to produce patterns which will repeat and be detected by our ears to keep the sound animated. As you can see in the screenshots you can use this module with other waveforms as well.

This version is laid out for stereo use. The left input is normalized to the right input so you can make a dense stereo field output from one single input wave. All phase shifters have different frequencies.

Specs and features

2 x Nine independent phase shifters
Volume control for all phase shifted waveforms
Takes a lot more then only sawtooth inputs
Mono in, stereo out
Runs on +/-15V and +/-12V
Power consumption around 120mA each rail

Implementation

Schematic

Multi Phase Stereo Waveform Animator schematic 02 main board — Multi Phase Stereo Waveform Animator schematic: Main board 2

Description:

You can find a detailed description of the multi phase waveform animator in EN#87 pg.3 ff by Bernie Hutchins.

Sound snippet: Plain single mono saw input. No filters or effect

Multi Phase Waveform Animator screenshot sawtooth waveforms — Multi Phase Waveform Animator screenshot: Sawtooth waveforms

Multi Phase Waveform Animator screenshot square waveforms — Multi Phase Waveform Animator screenshot: Triangle waveforms

Multi Phase Waveform Animator screenshot saw waveforms — Multi Phase Waveform Animator screenshot: Sine waveforms

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Calibration

None

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Building hints

Select the LFO frequencies to your liking according to the list in the downloads. You may want to us different values for the left and right side. I personally prefer the lower frequencies.