viper is a pack of four user oscillators for the Korg Prologue, Minilogue-XD and NTS1 that provide waveforms and wavetables from classic hybrid synthesisers:

  • viper-dw with 16 waveforms from the Korg DW-8000
  • viper-k3 with 31 waveforms from the Kawai K3
  • viper-esq with 32 waveforms from the Ensoniq ESQ-1
  • viper-ppg with 32 wavetables from the PPG Wave

Key features:

  • dual oscillators
  • high quality, alias-free synthesis core with 16 bit sample resolution
  • simulated multi-sampling allows tonal shifts at different key ranges
  • slew-rate limiting for glitch-free modulation
  • single-stage pitch envelope for ‘auto-bend’ effects and white noise generator1
  • wavetable modulation using the filter EG and shape LFO2

At the heart of viper are four additive synthesis models that reconstruct the original waveforms in real time Up to 128 harmonics to be generated with full anti-aliasing and 16 bit sample resolution, giving a clear, musical sound.

viper modelled waveform

viper’s models are extremely memory efficient as they do not need multi-samples to eliminate aliasing. However, they do use multi-sampling where tonal variation with pitch is important, such as the ESQ-1’s piano and formant sounds.

This space efficiency makes viper-ppg possible, with 276 individual waveforms used to construct 32 wavetables. Real-time interpolation permits both authentic ‘stepped’ wavetable sweeps as well as smooth, high resolution sweeps.

original DW-8000 waveforms viper modelled waveforms
DW-8000 original waveforms viper modelled waveforms


The following were recorded using a Korg Prologue. Unless otherwise stated, these use only a single voice and bypass the Prologue’s VCF.

viper-ppg wavetable 2 sweep using table stepping and 8 bit resolution to mimic the original PPG Wave:

viper-ppg wavetable 22 sweep, first with stepped interpolation and 8 bit samples, then with smooth interpolation and 16 bit samples:

viper-ppg wavetable 20 bass sound, using two oscillators with the filter EG modulating the table position:

viper-esq 80’s piano sound using two oscillators both with wave 10 (with apologies…):

viper-dw all 16 waveforms:

viper-k3 all 31 waveforms:

viper-esq all 32 waveforms:

User Guide

The user-guides can be downloaded here: viper-dw , viper-k3 , viper-esq and viper-ppg


viper requires a Korg Prologue , Minilogue XD (module or keyboard) or NTS-1 . viper does not support the Korg Drumlogue.

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.


Purchases include all four plugins for all supported platforms and help support future plugin development.

Click on the link below to open sellfy to purchase and download viper.

  1. viper-dw, viper-k3 and viper-esq only. ↩︎

  2. viper-ppg only; filter EG modulation is supported on the Minilogue XD and Prologue. ↩︎