Plane-Traversing Oscillator

That bouncing DVD screensaver is repurposed and modded into a chaotic oscillator in the Plane-Traversing Oscillator to tackle LFO-like duties and play (noisy) melodies as an audio oscillator. Oscillation is defined by a relationship between two points (one always moving and the other, movable by CV) on a planar surface (ok mathematicians, yes planes are supposed to be infinite) with definable and modulatable boundaries. All in all, the output is complex but also vaguely cyclic/periodic, for a well-balanced signal that teeters on randomness while also not wholly unpredictable.

For LFO-like modulation, adjust the rate of change switch amongst its various speed ranges and adjust the neighboring dials to affect horizontal and vertical travel rates. Those rates can be modulated for acceleration and deceleration. The output is derived from a point moving according to the above settings and a reference point, whose location is defined by the knobs just below, with x- and y-coordinate dials that can be pushed outside of the boundary area define by the surface dimension knobs further below. The reference point can move with CV inputs and the surface dimensions can likewise fluctuate with CV, each adding to the complexity and nuances of the final output signal by putting more moving parts into the machinery behind the oscillation. All of this together makes it essentially impossible to sync the output with tempo or even maintain a perfectly consistent tempo, but it is deterministic, i.e. each “step” is reliably followed by a particular next “step” so a reset jack (lower right) is provided to kick the device back to a starting point via some other LFO or sequencer that is tempo-synced or reliably periodic, giving you the best of both worlds.

Similarly, the chaotic nature of the oscillator makes it practically impossible to produce a steady pitch, but resetting the Plane-Traversing Oscillator at audio rate makes a wonderfully complex yet melodious result. An onboard pulse generator can be fed a typical 1V/oct pitch CV signal and it’s output (bottom right) can be jumped with a wire to the (slightly above) reset jack to turn this module into a musical oscillator. Drop the octave switch while raising the rate of change controls to tilt the balance toward greater chaos and less control. The output parallels what happens in wind instruments where physical dimensions define resonance and give different notes dissimilar tonal properties, making some notes noisier or weirder and creating interesting variations that support more interesting musical phrases.

At the top, you’ll find a handy volume control and a bias dial that lifts or lowers the center of the output signal, pre- or post-gain (there’s a switch) to support a range of affects upon other downstream modules.

Look to the Plane-Traversing Oscillator if you want modulation that strikes a balance between random and predictable, if you want an unusual compliment to your range of audio oscillators, and if you you’re looking for an interesting new way to add something a little wild to the mix.