The Mirage is the brainchild of Robert Yannes, the man responsible for the MOS Technology SID (Sound Interface Device) chip in the Commodore 64.

[1]: 75 The VLSI ES5503 allowed the Mirage to offer digital audio sampling technology at a dramatically lower price compared to existing competitors.

The Mirage is an 8-bit sampler featuring eight voices of polyphony, 16 accessible oscillators (or 32-oscillator wavetable synthesis upon loading alternative operating system), analog resonant Curtis CEM3328 4-pole 24-dB/octave filters, a 61-key velocity-sensitive keyboard or else 2U rack-mount module case, multi-sampling (up to 16 samples across keyboard), multi-timbral operation, extensive MIDI implementation, a two-digit LED display, a 333-event sequencer.

[2] It includes a built-in 3.5-inch SS/DD floppy disk drive, which is used to boot the operating system as well as to store samples and sequences.

Ensoniq later released an alternative OS called MASOS (Mirage Advanced Sampling Operating System), which trades off performance features for editing features, including the ability to copy an Upper sound to a Lower sound, and vice versa.

Alternative 3rd-party operating systems which substantially change and expand the synthesis capability and utility of the Mirage were produced.

The first Mirage (1984) had an all-metal case and endcaps, a keybed manufactured by Pratt-Reed, and large square black buttons.

Mirage DSK-8 (for Digital Sampling Keyboard, 8-voice) (1985) had small, gray, calculator-like buttons and a heavier-weighted-feel key-bed with polyphonic aftertouch.

[3]: 35–36 A fourth concurrent version of the Mirage, also model DSK-8 but manufactured in Japan for the Asian and Australian markets, was similar to the original American DSK-8 except for its flat, seamless membrane panel over the front-panel switches (similar to an original Yamaha DX-7 and most microwave ovens) and the addition of a recessed diskette holder well in the right end of the front panel – the opposite side of the keyboard from the floppy disk drive (the disk drive being mounted exactly as the American DSK-8, at the front edge of the keyboard between the modulation wheels and the left end of the keybed).