This page presents the WAVE-SHAPER Mk-II synth; a Cycling'74 Max/MSP patch that uses a synthesis method called Phase-Distortion (PD) which I learned of from the book 'The Computer Music Tutorial' by Curtis Roads. Phase-Distortion was invented by Casio, and was used in many of their synthesis instruments; a simple but effective way of re-shaping a sine wave. This is achieved by reading the wave in two stages - 0 to pi, and pi to 2pi, at different rates. (see info below)
The WAVE-SHAPER_Mk-II patch extends this idea by allowing complex, continuously cross-fading audio buffers to set the way that two oscillators are read, creating very diverse, rich & complex timbres.
The WAVE-SHAPER_Mk-II synth is my first synth that uses a specifically made 3D model as a Graphical User Interface.
—«o: WAVE-SHAPER_Mk-II: Interface:o»—
—«o: OSCILLATOR SECTION :o»—
—«o: WAVESHAPER: Max/MSP G.U.I. :o»—
—«o: ABOUT PHASE-DISTORTION :o»—
Simple Phase-Distortion synthesis involves a specific kind of
frequency modulation that distorts the oscillator it is driving by reading it at
two different rates that equate to the base frequency. This can be visualized by (and programmed by)
an audio buffer, driving a cosine oscillator lookup table. (See inset illustration)
The inset image to the right shows how a sine-wave can be distorted by the PD-wave. The top half of the illustration shows how a look-up table with values from 0 to 1 can drive a sine-wave oscillator (this is achieved in Max using a wave~ object holding the 0-1 buffer connected to the phase inlet of a cycle~ oscillator).
The second half of the illustration shows the effect of the phase-distortion on the sine-wave; where the sample value reaches 0.5 in the PD-buffer (corresponding to half way through the oscillator's 2pi phase) can be moved in the X-axis, stretching and contracting each half of the resulting sine-wave.
The effects of these distortions cause the oscillator to take on either a quasi Saw or Tri-like waveform, with increased sonic character in both directions.
—«o: MORE TO COME (real soon 05/10/09) :o»—
—«o: DOWNLOADABLE'S :o»—
I will post some downloads of the WAVE-SHAPER_Mk-II real soon. .
I will make it available as a STANDALONE application (which includes its own version of Max-Runtime, and can be run without Max Runtime installed - WINDOWS ONLY - Sorry!!) & perhaps a text-version too!
Maybe in a week? (Posted today - 04/10/2009)
—«o: WAVE-SHAPER_Mk-II (Coming soon!) :o»—
