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Korg X5DR

Synth Module By Derek Johnson
Published May 1995

More notes, more waveforms, but more money... Is this new module from Korg just more of the same? Derek Johnson finds out...

It can't have escaped your attention that Korg have recently been smoothing their way into the forefront of synth development; the Wavedrum, Oasys and Prophecy (see preview on page 32 of this issue) are using cutting‑edge DSP and physical modelling technologies to inject something new and different into the marketplace. Unfortunately, it's a fact of life that cutting‑edge technology does not come cheap, so it should come as no surprise that Korg are continuing to support their established AI2 family of 'sample + synthesis' instruments.

The latest AI2 machine is the X5DR, a 16‑part multitimbral, General MIDI‑compatible half‑rack sound module that has rather a lot in common with the X5 and the 05R/W (reviewed January 1995 and October 1993 respectively). The DR is packaged in an identical box to the 05R/W, and is backwards compatible with both machines. But the X5DR does offer a couple of significant enhancements. First of all, double the polyphony — a rather impressive 64 notes — and hyped‑up waveform ROM of a jaw‑dropping 8Mb (as opposed to 6Mb on the 05R/W and X5). This translates into 430 Multisounds (Korg‑speak for basic waveforms) and 215 drum sounds.

Inside Story

We've established that there are no surprises on the looks front — the user interface consists of an immediately familiar selection of small parameter buttons to one side of a small display. As with the 05R/W, this makes editing the DR a slightly fiddly business. Audio and MIDI connections are at the rear and are joined by the now rather familiar PC/Mac interface, immediately saving you the expense of buying a MIDI interface for your computer.

We've introduced Korg's AI2 synthesis technology so many times that there is little left to say about it; but for the tyros amongst you, here's the Coles Notes version. The basic building block of every AI/AI2 instrument, going back to the M1, is a multi‑sampled waveform called a Multisound. Each basic Program (patch) uses one or two Multisounds, although using two Multisounds halves the available polyphony. There follows a range of fairly traditional synth parameters, including a pitch envelope generator, VDF (Variable Digital Filter), VDA (Variable Digital Amplifier), and various modulation options. Note that the filter lacks true resonance, with a 'Colour' parameter instead. The X5DR also implements Korg's quality digital effects; there are two processors, with 47 effects to choose from. Several are dual effects in their own right, and in combination with a variety of routing options, this makes for quite complex effects possibilities. In common with the X5 keyboard synth, the DR has a wide range of alternate tunings, which is always welcome.

Up to eight Programs can be used in what Korg calls a Combination; the Programs can be split, layered or used multitimbrally. The DR's extended polyphony really shines here, since very complex, layered Combis won't compromise polyphony to the extent of earlier machines. Compare this to the venerable M1's 16‑voice polyphony.

Last of all, there is a single Multi(timbral setup), just like the X5. This is ideal for producing full 16‑part multitimbral arrangements and for playing back MIDI Files in GM format. As with the X5, any settings made to the Multi are lost on power down, so you'll need to get the hang of using program changes in your sequences.

What's New?

To take full advantage of the extra 2Mb of waveforms, Korg have provided the X5DR with two banks of factory presets, each containing 100 Programs and 100 Combis, although only one bank can be loaded at a time. One bank is totally new and takes advantage of the additional waveforms, while the other bank is identical to that found on the X5 and 05R/W. Individual Programs and Combis can be loaded from either factory bank to create a custom bank (again, of 100 Programs and 100 Combis), and it is possible, of course, to edit fresh Programs and Combis from scratch. Note that your custom bank should be saved over SysEx (no card slot, I'm afraid), since re‑loading either factory bank will overwrite your work. And, of course, there is an independent bank of preset General MIDI‑compatible Programs — you can tweak these and save them.

In Use

Operationally, the main problems with the X5DR are, inevitably, due to its size. This isn't Korg's fault especially, but is common to all sound modules in such small packages. Apart from that, navigating the X5DR is fairly logical and straightforward, although dedicated sound designers will be crying out for a software‑based remote editor or mixer map. The one functional oddity I discovered was a lack of an Edit/Compare facility.

As a desktop music tool, the computer interface (plus Korg's optional connection kit) makes the X5DR ideal for compact systems where GM playback is a must; the more demanding will like the fact that this is a fully‑functioning Korg AI2 synth with added waveform ROM, in a box that won't take up much room in the studio. Sonically, I have no complaints: benefiting from the latest generation of AI2 technology, the DR's basic samples are clean and smoothly looped, and the new waveforms add to an already impressive set. If it's instant gratification you're after, check out the two sets of factory Programs and Combis, plus the General MIDI sound set, which is very high quality indeed.


Until very recently, 64‑voice polyphony on anything would have been cause for major gold stars. However, though this kind of polyphony isn't quite ubiquitous yet, it's certainly not the impossible dream it once was (indeed, it's a real pity that the excellent X5 keyboard, released just a few months ago, was not blessed with the DR's extras — why not?), and a synth can't rely on this bonus alone to make it successful. I feel that Korg could have made the X5DR a little more individual by adding, for example, an extra MIDI In and 32‑part multitimbrality (a la Roland SC88 Super Sound Canvas and Yamaha MU80), and seeing it stretched out into a full rack box might have added to its perceived value (it can be difficult to come to terms with paying almost £700 for something so small), as well as providing extra space for a larger display and more buttons. However, once you accept that the X5DR is simply a repackaged, enhanced version of existing technology (and therefore low on excitement level), it presents good value for money, with a built‑in computer interface, bags of extra waveforms which add up to some very high‑quality and usable sounds, and so much polyphony that even if this was your only sound source, it would be some time before you hit the polyphony log‑jam common with less well‑endowed instruments. Korg tell us that this baby is positively walking off retailers' shelves, and in the context of the aforementioned advantages, it's not hard to see why.

Sound Stuff

As mentioned earlier, the X5DR has been enhanced with regard to polyphony and extra waveforms. On the waveform front, the first 340 Multisounds (and 164 percussion sounds) are identical to those found on the X5 and 05R/W. The remaining 90 Multisounds and 51 percussion sounds include a motley, but entirely useful, collection of extra organs, drums, tuned percussion, basses, winds, synth textures, and a piano. Some of these are brand‑new samples, but many are taken from previous Korg instruments and their card libraries, making the DR a very good way of obtaining the sounds of Korg synths from the M1 to the T‑series, 01‑series and Wavestation. Needless to say, the aforementioned piano is the famous M1 piano. Especially interesting are the sound effects: drills, cork pops, jets, harp glissandos and the like abound, not to mention coughs, grunts and squeals produced by sundry animals and people. It really is an excellent source of sonic raw material, though it has to be said that certain of the new sounds may become cliches if over‑used in anything like their untreated state.

For anyone who hasn't heard the sounds that Korg's AI2 synthesis produces (and where exactly have you been for the last 10 years?), the X5DR is typical of the family: the basic sample set is uniformly good, and the factory preset Programs and Combis get high marks for instant playability. Highlights appear amongst string sounds, synth pads, basses and impressionistic, ambient textures, while Combi mode offers even more potential for creative sound layering.


  • AI2 synthesis.
  • 8Mb sample ROM: 430 Multisounds and 215 percussion sounds.
  • 64‑voice polyphony.
  • 16‑part multitimbrality.
  • 100 User Programs.
  • 136 General MIDI programs.
  • 100 Combinations.
  • 1 Multitimbral setup.
  • 2 independent digital multi‑effects with 47 effects.
  • Alternate tunings.
  • Computer interface for Mac and PC.


  • Bags of polyphony.
  • Great new waveforms.
  • PC/Mac port.


  • No filter resonance.
  • No Edit/Compare facility.
  • Small display.
  • Multi resets to default on power down.


Polyphony and 2Mb of extra Multisounds aside, the X5DR is basically a case of refinement and consolidation rather than revolution. As a compact and not unaffordable way to bring the Korg sound to your desktop, it's a good choice.