KX-Synth-X16 is a virtual analog modular synthesizer inspired by the classic EMS VCS3 design, enhanced with modern capabilities. It features three variable shape oscillators that emulate the distinctive tonal character of the original VCS3 oscillators. The instrument includes a 16 by 16 pin matrix for flexible patching and feedback connections, along with an 18 dB per octave low-pass filter capable of self-oscillation. Additional sound-shaping tools include a noise generator with EQ, ring modulation, two external inputs, and an intuitive XY joystick for real-time control.

Expanding beyond the original VCS3, KX-Synth-X16 offers polyphony of up to six voices, fully controllable through the advanced modulation system. Each voice can be independently shaped with detailed parameter settings, enabling complex and expressive performances. An integrated analog-style sequencer supports up to 256 steps for both control voltage and gate signals, with features such as accents, random clocking, and keyboard input for transposition or recording. The interface includes mini knobs for fine-tuning modulation amounts, a modern customizable skin, and a comprehensive help file to guide users.

The synthesizer further includes extended envelope options, such as dual ADSR envelopes with synchronization to host and internal sequencers, as well as additional LFO and sample & hold modules. Effects include a delay with tempo sync and modulation, replacing the traditional spring reverb. MIDI capabilities are extensive, featuring full MIDI CC support for all main parameters, velocity responsiveness, MIDI input splitting, and omni output to control external instruments. The package is complemented by a wide selection of presets, ranging from polyphonic and monophonic instruments to sequencer demos and tutorial patches, making it a powerful tool for creative sound design.