Plexigan | Adam Sporka Home Page



Plexigan is a VST emulation of a hypothetical music instrument, inspired by 1970s instrument called the Optigan.

It has 9 tracks (channels) on the disk which rotates. Each track is read by its own dedicated playhead. When read at the nominal speed, the tracks represent typically these notes but other configurations may exist:

  Channel    1    2    3    4    5    6    7    8    9
  Nominal   C3   G3   C4  D#4   G4  A#4   C5   E5   G5

When one of these notes are played, the output from the corresponding track is simply passed to the output.

When a note that isn't listed needs to play, Plexigan chooses the channel with the nearest nominal pitch and then either slows down or speeds up the rotation, just like a turn table plays the music higher or lower depending on its current RPM.

All notes are on the same disk, which means that the entire bank of notes would play higher or lower. That means that when playing multiple notes at the same time (Polyphonic Mode), only some combinations of notes can be played. Some will be impossible and won't play.

Plexigan will always try accommodating what you play but by doing so, it will glitch, which gives it the characteristic sound.

Main Features

  • VST3 for Windows
  • Global Attack, Global Release
  • Channel Attach, Channel Release
  • Vibrato Frequency, Amount
  • Laziness
  • Mono- or Polyphonic Mode
  • Homing on/off


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