Example of Delay processing an external audio signal played from a phone.
The Delay is at times being modulated with an LFO (also a miniMO)

miniMO's Delay is a voltage-controlled experimental  digital delay, with the ability to alter its feedback, buffer size, and processing rate (more details here).


Download from Github


  • Real time control of feedback, buffer size and processing rate
  • External modulation of either feedback, buffer size, or processing rate
  • Automatic Battery check



  • 1&2: Outputs - processed signal
  • 3: Input - parameter modulation
  • 4: Input - audio signal


  • Knob: change feedback (default), buffer size or sample rate
    • miniMO waits until you reach the value it has currently stored
  • Click: toggle between feedback, buffer size and delay time control
    • The LED blinks 1 to 3 times depending on the parameter selected (1-Feedback, 2-Buffer, 3-Rate)


When you switch the module ON,

  • If the LED blinks once, the battery is OK
  • If the LED blinks fast several times, the battery is running low


  • Feedback can be driven to the point of self-sustain, producing loud tones - be careful! (or -enjoy!)
  • With Processing Time left to 0, the unit works as a conventional delay with a very short delay time (up to 30ms), determined by the buffer length. Increasing the Processing Time yields longer delays, but it also further modifies the processed signal, lowering its tone and/or introducing new ones in a sort of ring modulation


This Delay is based on the Arduino Audio Reverb by Martin Nawrath, as described here.