One of the great strengths of polyphonic analog synthesizers is unison—or stacked voices—mode. Unison mode in polyphonic analog synthesizers is typically monophonic, with all voices playing simultaneously when a single note is struck. Because the voices of an analog synthesizer are never perfectly in tune, the result is an extremely fat chorus effect with great sonic depth.
Click the Mono or Legato button, depending on the keyboard mode you want to use. See Set the ES2 keyboard mode.
Click the Unison button.
The intensity of the unison effect depends on the number chosen in the Voices parameter field. Increase the Voices value for a fatter sound. See Global parameters overview.
The intensity of detuning (voice deviation) is set with the Analog parameter. See ES2 emulation of detuned analog oscillators.
Click the Poly and Unison buttons.
In poly/unison mode, each played note is effectively doubled—or, more correctly, the polyphony value chosen with the Voices parameter is halved. These two voices are heard when you trigger the note. Poly/unison has the same effect as setting the ES2 to mono/unison (Voices = 2), but you can play polyphonically.