Nabla ∇ – v1.4.0 [10-Feb-2026]

The Nabla is a software instrument for Microsoft Windows (VST2/VST3/CLAP/AAX) and Apple macOS (VST2/VST3/AU/CLAP/AAX) simulating the KORG Delta DL-50 Strings Synthesizer from 1979. Is is written in native C++ code for high performance and low CPU consumption. The main features are:

• Paraphonic Synthesizer and Strings sections
• Up to 64 voices polyphony
• Synthesizer section:
  • Four band-limited frequency divider-driven signal generators
  • Additional noise generator
  • 4-pole zero-delay feedback bandpass/lowpass filter
• Strings section:
  • Two band-limited frequency divider-driven signal generators
  • 2-band equalizer
  • Ensemble effect
• Flexible pitch/filter modulation by LFO or noise
• Tweaks (not to be found in the original Delta):
  • "GOD Mode" to provide true polyphony
  • Panning for Synthesizer/Strings sections
  • Built-in phaser and delay effects
• Double precision audio processing
• All parameters can be controlled by MIDI controllers
• Plug-in supports Windows and macOS (32 bit and 64 bit)

On the track "nabla", the Nabla is the only audio source (plus some delay, reverb and slight compression).
...and of course Kraftraum's Autobahnnacht... you can find the patches used for this great track below!

Learn how to install Nabla on your Mac!

Kraftraum has created a set of amazing presets for Nabla which is exclusively available for download here:

Nabla was subject of KVR's One Synth Challenge #96 (OSC)!
Go to the official OSC website and listen to the submissions of this great event!

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