Digital ramp up/ramp down signal generator with wide frequency range and one-shot modes – usable as a LFO, a VCDO or an AR/AD generator.

Features, controls, I/O

  • Cycle mode selector: single shot AD, single shot AR, looping (VC-LFO/VCDO).
  • Frequency range selector: low (20 minutes to 5 Hz), medium (0.05 Hz to 300 Hz), high (8 Hz to 10kHz).
  • Frequency control, with 1V/Oct frequency CV input.
  • Exponential FM CV input, with attenuverter.
  • Shape control with CV input – covering various combinations of linear, exponential, or raised cosine segments.
  • Slope/asymmetry (A/D time ratio) control with CV input.
  • Smoothness control with CV input. From 0V to -5V, smoothes the waveform using a 2-pole digital filter, from 0V to +5V, adds bumps and kinks with a digital wavefolder.
  • Unipolar CV input controlling output level.
  • Trigger input, which works as a trigger in AD/AR modes and a sync/reset in looping mode.
  • Clock input to “tap” or “ping” the LFO and envelopes, or to lock the VCDO frequency through a PLL. In these cases, the frequency control acts as a frequency division/multiplication control.
  • Freeze gate input to stop the oscillator and hold its output.
  • High tide and Low tide gate outputs for chaining/quadrature operation, or other applications such as gate delaying.
  • Unipolar (8V) and bipolar (+/- 5V) outputs, with a distinct shape/character.

Technical characteristics

  • All inputs: 100k impedance, DC to 500 Hz for shape/slope/smoothness, DC to 3kHz for FM, DC to 24 kHz for level.
  • 12-bit CV acquisition with separate power supply for converters and references.
  • 16-bit CV generation, 48kHz sample rate (12.5kHz in the lowest frequency range).
  • Cortex-M3 ARM processor.
  • Open-source hardware and firmware.
  • 14-HP.
  • Easy firmware updates through an audio interface.
  • Current consumption: +12V: 55mA ; -12V: 5mA.

Olivier Gillet, Mutable instruments SARL 2011-2017. Except where otherwise noted, content on this site is licensed under a cc-by-sa 3.0 license.