DISTORT: Detailed Information

by Archer Endrich

Key Features of the CDP DISTORT set

• Wavecycles are specially defined as that part of a waveshape that lies between zero crossings. Also called 'pseudo-wavecycles' because true waveforms may cross the zero line more than once. The lengths of the wavecycles defined in this special way differ, which causes the distortion.



• Various standard procedures are recreated in distorted form by using these special wavecycles as the starting point: e.g., high, low and band pass filtering, time contraction and stretching, shuffling, creating harmonics, lowering and raising frequencies.



• A more complex form of distortion is achieved by using wavecycles from two different sounds.

Some possible musical results with DISTORT

• In general, this form of wavecycle distortion produces a relatively soft-edged burbly sound. The transformation works its way through the source sound.



• The source can be time-contracted (DISTORT DELETE, DISTORT OMIT or DISTORT TELESCOPE) or time-extended (DISTORT REPEAT). Further modulating with time-varying enveloping or vibrato functions introduces some variation in the signal. It can then be interesting to run the result through a fine-grained GrainMill to achieve a smoother but constantly modulating granular texture.



• Enveloping the wavecycles with DISTORT ENVEL or DISTORT REFORM creates subtle repeating effects, and this can be done with variations in different channels and then recombined to create subtle phased effects.



• Layering wavecycles with DISTORT FRACTAL or DISTORT HARMONIC creates more complex distortions.



• The DISTORT FILTER function removes wavecycles of certain lengths, the longer being lower and shorter being higher in pitch: thus the high pass, low pass or band pass effects are created. DISTORT PITCH also affects the pitch, with time-varying controls over the pitch range and the length of the wavecycles.



• DISTORT INTERPOLATE provides a powerful combination of repetition and gradual change. You can specify how many times a given wavecycle is to repeat (causing time-extension and repetitive effects), and during this time it also gradually changes into the next waveycle, causing smoother enveloping and various glissando effects. I have found it most effective when applied to strong attacks, creating rushing, whistling sounds with lower values for the repeat parameter and mad tin-whistle tunes with higher values. Spectral-domain timestretching prior to using DISTORT INTERPOLATE produces a finer and smoother texture in the wavecycle repetitions.

Other forms of distortion in CDP

• BLUR NOISE introduces noise into the spectrum.



• BLUR SPREAD spreads the peaks of the spectrum, which also introduces noise.



• There is a noise element which comes into the attack portion of sounds transformed with HILITE PLUCK.

General observations

• Parameter values close to 1 (above or below) maintain the recognisability of the source. As values move away from 1, the distortions become more extreme and the recognisability of the source diminishes.



• The DISTORT functions create a variety of distortion effects, from subtle to very intense transformations.



• One of my favourites is DISTORT REPEAT, which works well with highly modulated sounds, and also produces an extended churning sound which lends itself to further transformations.

Last updated: 4 December 2003