DS80-VCDO

New: version 1.1 update with bug fixes and velocity modulation of the Filter EG .

ds80 is a Logue user-oscillator which emulates the digital waveforms from the vintage Digisound DS-80-21 VCDO rack module .

Key features:

  • 32 waveforms in 4+1 banks
  • reproduces variable-sample-rate waveform artefacts
  • alias-free sample generation
  • single oscillators plus white noise
  • waveforms can be selected individually or swept smoothly as a wavetable
  • bandwidth limiter
  • analogue tuning drift
  • Filter EG modulation of wavetable position, incorporating velocity sensitivity

The plugin is a free download and uses the same technology as viper which uses additive wavetable synthesis to emulate the Korg DW-8000, Kawai K3, Ensoniq ESQ1 and PPG Wave .

The original hardware can produce 32 waveforms, organised as four banks of eight:

  • Bank 1: wavetable 1
  • Bank 2: wavetable 2
  • Bank 3: wavetable 3
  • Bank 4: individual waves (triangle, square, sawtooth, double-sawtooth, pulse, random1, square+sawtooth and random2)

ds80 adds a 5th bank, which consists of all 32 waveforms sequentially.

The DS-80-21 hardware is very simple, using a tiny 2K EPROM with a voltage-controlled counter that steps through samples sequentially. The individual samples are very short - only 64 samples each, giving a lo-fi sound that is unique at lower frequencies thanks to the very coarse steps.

ds80 is based on the EPROM samples and does not attempt to model the surrounding analogue circuitry. However, it does model the variable sampling rate of the original which is one the main sources of the original hardware’s characteristic sound.

Note that some ds80 waveforms may look visibly different from the original sample data (eg: the pulse waveform), although in practice they sound identical. This results from phase adjustments that are made when encoding the waveforms for the additive synthesis engine.

Parameters and Controls

Front Panel:

  • Shape: selects the waveform in the current bank; smoothly sweeps waveforms if the Step parameter is increased.
  • Shift+Shape: adjusts the balance between the oscillator and the white noise generator

Parameters:

  • Bank: selects the waveform bank; 1 - 4 mimic the original DS-80-21, while 5 is a single bank with all 32 waveforms
  • Step: controls interpolation between waves; use larger values for interpolation between waveforms
  • Pitch: sets the pitch of the oscillator, in range -1 octave to +1 octave
  • Bandwidth: allows the oscillator bandwidth to be progressively reduced (analogous to low-pass filtering)
  • Drift: if set non-zero, allows a subtle tuning drift to model control voltage drift
  • FEG Gain: if non-zero, the Filter Envelope Generator will modulate shape (ie wavetable position)

Be aware that there is some interaction between the FEG Gain parameter and the Filter EG velocity sensitivity. When the Filter EG velocity sensitivity is zero, an FEG gain of 100% will exactly sweep the full wavetable. When the Filter EG velocity is 127, the FEG gain should be backed off to approximately 50% so that only the fastest key-velocity reaches the maximum modulation level.


User Guide

The user-guide can be downloaded here (PDF).

Compatibility

ds80 requires a Korg Prologue , Minilogue XD (module or keyboard) or NTS-1 . The Korg Drumlogue is not supported.

To load the user-oscillator you will need a macOS or Windows computer and USB cable, together with the librarian software available from Korg for your synthesiser.

Download

ds80 is free. Click here to download a zip archive of DS80 version 1.1 1.

Version history:

  • Version 1.0 2023-12-21: Initial release.
  • Version 1.1 2023-12-28: Corrected the ‘Table’ parameter range. Added velocity modulation of FEG Gain.

If you find this useful, please consider buying some of our other plugins or leaving a comment below.


  1. The MD5 checksum for the ZIP archive is cb0b6bba06d54c05ffb962e620ddbc30. ↩︎