A family of Korg synthesizers introduced around 1994.
- Korg O5/RW -- a rackmount 32-voice synth (a feature-reduced X3R, actually)
- Korg X5 -- the O5/RW with keys
- Korg X5D -- the X5 with 64 voices and another bank of sounds (the X5 sounds become the B bank and the new sounds are introduced as the A bank)
- Korg X5DR -- rackmount version of the X5D
To date, the X5D and X5DR are still being made and are among the cheapest (and longest-running) all-purpose digital synthesizers around. They come with 8 mebibytes of wave memory and something called AI2 synthesis, which means more or less playing samples through multieffect DSPs, of which there are two onboard with 47 effect types to chose. It's possible to do advanced editing with the X5 series (more so than with the Roland RS-5, for example) but it's like building a boat in a bottle because everything must be done through a tiny LCD, six buttons and a value slider. I consider the X5D user interface very uncomfortable and I think the X5DR rackmount can only be worse.
They come with two ROM sound banks (A and B) at 128 patches each and a General MIDI bank, plus 100 storage places for custom programs ("Tones" for Roland users and "Voices" in Yamahanese) and 100 places for custom combinations (called "Performances" by Roland and Yamaha). The X5D(R) has three modes: program mode, where you play just one patch; combi mode, where up to eight patches can be combined by splitting, layering, velocity switching etc.; and multi mode, where it does 16fold multitimbrality.
On the X5D, there are the standard 61 velocity-sensitive keys, bending wheel and modulation wheel. The keyboard feels cheap and is so noisy that, when playing at normal room volume, the clacking keys are sometimes louder than the actual music.
The big advantage is that you can get an X5D for less than 500 euros by now (May 2002), and with Korg's next-level synth being the Korg Triton Le at ca. 1700 euros, the company would be stupid to discontinue this rather old, but cheap machine.