Nabla is a software instrument designed for both Microsoft Windows and Apple macOS platforms, emulating the classic KORG Delta DL-50 Strings Synthesizer from 1979. Developed with native C++ code, it offers efficient performance with low CPU usage, making it suitable for demanding music production environments. This plugin supports multiple formats including VST2, VST3, AU, and CLAP, ensuring broad compatibility across various digital audio workstations.

The instrument features separate paraphonic synthesizer and strings sections, delivering up to 64 voices of polyphony. The synthesizer section includes four band-limited frequency divider-driven signal generators alongside a noise generator and a 4-pole zero-delay feedback filter with bandpass and lowpass modes. Meanwhile, the strings section offers two band-limited frequency divider-driven signal generators, a two-band equalizer, and an ensemble effect, capturing the rich textures of the original hardware while adding modern sound-shaping capabilities.

Nabla enhances the original design with several unique features such as a 'GOD Mode' for true polyphony and panning control for both the synthesizer and strings sections. Additional built-in effects like phaser and delay further expand its sonic palette. The user interface is resizable for improved usability, and all parameters are MIDI-controllable, allowing for expressive live performance and detailed programming. This combination of vintage sound emulation and contemporary flexibility makes Nabla a compelling choice for musicians seeking classic string synth tones.