The performance capabilities of the VFX's made it a favorite for live musicians, as up to three voices can be selected, combined into a Preset (20 user presets in memory at a time, 40 built-in) to play from at any given time and saved in a custom-programmed setup (each sound in the PRESET allowed for Transpose, Output Routing,
MIDI channel assignments, EFX routing/selection, etc.). Since each voice could be made of up to six individual sounds, the possibilities were very wide-ranging, such as using different key-ranges/splits for each of the six voices (although it significantly ate up polyphony). One particular feature that the VFX (and VFX-SD series) had was "Poly-Key Pressure" (better known as Polyphonic Aftertouch). This allowed the player to add modulation to each
single note when playing chords. Most synths use the more common (and less expensive to manufacture) "Channels Aftertouch" which adds equal modulation to all keys at a time on a given MIDI channel. An Ensoniq specialty that appeared in almost all of their products were the two "PATCH SELECT" buttons above the Pitch/Modulation wheels. These two buttons were used to select four different oscillator combinations of a sound. The mapping was fully programmable and was invaluable for creating more versatile sounds for performance. Ensoniq had other MIDI modes in addition to the standard Omni and Multi modes:
Mono A and Mono B. These were particularly effective when using a guitar synth and allowed for more realistic playing of the sounds. Mono A allowed for the same sound to be played across the MIDI channels and Mono B allowed for each MIDI channel to have a different sound. ==The sequencer==