A "rungler" is an invention of synth builder Rob Hordijk. It is an analog shift register whose output is determined by the state of the three most significant bits (6, 7, and 8). What does that mean? Well, it might be easier to think of it as a stepped random source, but with only 8 possible random values.

The Rungler has two mandatory inputs: Clock and Data. The Clock input advances the shift register whenever the 1V threshold is crossed. If the Data input is greater than the value set by the Compare knob, a positive bit is added to the shift register.

The classic Rungler patch is as follows:

  • Create two oscillators. Plug the square or saw wave of one oscillator into the Clock input, and any waveform from the other oscillator into Data.
  • Plug the Rungler's output into the FM inputs of both oscillators.
  • Adjust the FM depth of each, experiment with Write/Loop, change the Compare and Scale values.