Control Drift


Also available in The Drift Pack at a greatly reduced price!

Control Drift can function both as a random drift signal processor and generator/oscillator.

When the input jack is connected, the module introduces gradual random fluctuations to the incoming control signal, causing it drift and wander around the original value. Route an LFO, envelope, or any other CV signal through the module to make it a little more interesting and unpredictable... When the input jack is not connected, the module outputs a drifting CV signal useful for controlling other modules.

The module can work either in addition or multiplication mode, set by the MODE switch. In addition mode, the incoming signal and the drift signal are summed, and in multiplication mode, they are… yes, multiplied. Set the range for the drift signal with the LOW and HIGH knobs. In addition mode, the maximum range is -5 to 5 volts, and in multiplication mode -2 to 2 volts. The RATE knob sets the speed of the drift.


  • In multiplication mode, negative drift values flip the phase of the input signal, which can lead to cool effects.
  • When the input jack is not connected and the module works as a signal generator, when you turn the module off by clicking the ON button, the output resets to 0 in addition mode, and to 1 in multiplication mode.
  • The limits you set with the LOW & HIGH knobs are accurate. It's possible the drift signal will touch the limits, but it will not exceed them. (If you just run noise through a low-pass filter, you get a similar drift signal, but it can be difficult to set exact limits for it.)
  • If you set LOW higher than HIGH, the values are just switched internally. The random range is always between these two values, regardless of which one is higher.


  • To add small imperfections to a bipolar LFO, route it through Control Drift, set mode to addition, and LOW and HIGH symmetrically (e.g. -1 and 1 volts). Set RATE to taste.
  • To introduce variations to the shape and amplitude of an envelope, so that the modulated envelope never exceeds the amplitude of the original: Set mode to multiplication, HIGH to 1, and LOW to the desired lowest random level (with 0 being silence).
  • To make an LFO go crazy, set mode to multiplication and LOW and HIGH to -1 and 1. When the drift signal goes to negative values, if flips the phase of the LFO, and in case of a sawtooth wave, also reverses it.
  • To add subtle instability to something like a filter cutoff or oscillator pitch, just connect the output of Control Drift to the modulation input of the filter/oscillator module, and set RATE close to one.