The Rear Panel
The rear panel of the original Minilogue was rather sparse, with audio I/O limited to a single quarter-inch monophonic output, a single quarter-inch audio input and a quarter-inch TRS headphone output. In addition, it sported 3.5mm Sync In and Out sockets, 5-pin MIDI in and out connectors, plus a USB B‑type socket that carried MIDI but not audio. Despite losing the audio in, the XD improves upon this with three important additions. Firstly, the audio output is stereo, so the on-board effects can spread sounds across the panorama for much nicer results. Secondly, there are two ±5V CV inputs that allow you to control many aspects of its sound from other equipment such as Eurorack modules and sequencers. Thirdly, there's an input for a sustain pedal.
To the far left of the panel there's an input for the external power supply, a cable hook, and an on/off switch. I would never take anything with miniature keys on stage, so maybe the use of a wall-wart is not as much of a problem here as it would otherwise be. On the other hand, I would be very happy to use the XD 'live' as a sound module and access its sounds from a full-size controller, so maybe it is.
In Use
Given its similarities to one half of the bi-timbral Prologue it should come as no surprise that I was able to conjure some great sounds from the XD. There were a few occasions when I craved a more powerful filter but, more often than not, I liked how the existing one 'breathed' and allowed patches to sound open and natural. I also made good use of the filter overdrive, and I liked being able to send digitally generated sounds directly to the VCAs to mix them with filtered analogue sounds.
As for the sounds themselves, these ranged from the simplest timbres to immense soundscapes, from delicate fairy-dust patches to overpowering lead synths and basses. In fact, it was sometimes difficult to reconcile what I was hearing with what I was seeing and touching — the XD seems too small to be capable of generating some of the sounds that I created on it. With it sitting on top of an 88-note master keyboard and acting as a four-voice analogue sound module, I found that — despite its limitations — it's not a synth to be dismissed lightly.
When you've created your sounds you'll find another improvement over previous models. Whereas the original Minilogue offered just 100 user memories and the Prologue offered 250, you can save up to 300 of your own Programs in the XD. On the other hand, the sort and favourites/live‑set functions of the Prologue are more advanced than those on the XD, which, given both synths' inability to jump directly to a Program, isn't trivial. Scrolling through 500 of the sodding things (even using the Shift+scroll function to jump in steps of 10) can be very frustrating.
Performance control on the XD is limited to portamento and its X/Y joystick, but the latter is a huge improvement over the slider provided by the Minilogue. Its X axis is permanently assigned to pitch-bend, and you can determine the maximum amount of bend independently for the X+ and X- directions. In contrast, its Y axis is assignable and you can select one of 29 possible destinations for each of the Y+ and Y- directions, with independent amounts for each. In my Minilogue review in 2016 I noted that some of Korg's vintage synths allowed you to apply pitch-bend (left/right) and two types of modulation (forward/backward) to a sound, and suggested that it was a shame that the Minilogue didn't do likewise, so it's nice to know that somebody was listening. I accept that some people prefer pitch-bend and modulation wheels, but I find joysticks to be much easier to use and they're more flexible too.
The other major addition is the provision of the dual CV inputs that I've already mentioned. Using these couldn't be simpler. In CV+gate mode you can present suitable CV and gate signals to play the XD monophonically from another synth. In modulation mode, you direct suitable signals to these inputs, set their gains (ie. the amount of modulation) and choose from 29 possible destinations, and away you go. I had the XD sitting in front of a modular synth throughout this review, and the possibilities were immense. In my view, these inputs alone could justify selling an original Minilogue to buy the new one.
But despite all the good stuff, there are further ways in which I would have improved the XD while the opportunity presented itself. For example, when I reviewed the original Minilogue I suggested that Korg implement MIDI Overflow so that users could cascade synths for 8-, 12- or even greater polyphony. It hasn't happened. Maybe the company's reasoning was that this would have trodden on the toes of the Prologue, which is understandable. There's also the issue of the 'slim' keyboard. For me, a synth with two-and-a-half octaves of full‑size keys would be a better instrument than one with three octaves of miniature keys. But again, there's the Prologue... so maybe I understand Korg's reasoning here too.
So what's the catch? As before, it lies in the XD's MIDI implementation. My biggest complaint regarding the Minilogue was reserved for its non-standard use of MIDI CCs. One or two of those mis-assignments have been fixed (CC 5 is now portamento, and CC 64 now controls the damper function as it should) but many of them conflict with the published MIDI specification. I had no idea why Korg implemented MIDI in this way on the Minilogue and I have no idea why the company still do so on the XD. What's more, while the XD manual states that "the Prologue [sic] lets you assign MIDI Control Change numbers (CC) to the major parameters that affect the sound" it's still not true; unless I've missed something, there's no way to assign CCs. Oh yes, and while we're talking about MIDI, I can forgive the lack of aftertouch on the XD's mini keyboard, but omitting it from the synth's MIDI capabilities is a missed opportunity.
Conclusions
I was very happy when I heard that Korg were going to release an updated version of the Minilogue because, despite its limited polyphony, miniature keys and weird MIDI map, I liked the original rather more than I had expected. The same is true of the XD and, although there are some aspects that I wish that Korg had implemented differently, finding the soul of the Prologue in something as small, convenient and affordable as the XD should excite many people who want a largely analogue signal path, a bit of polyphony, and a great sound. Although it's about £$100 more expensive than the original Minilogue, the XD is still not expensive; indeed, I think that it's better value than the original.
The Librarian
The Minilogue offered 45 parameters in its three menus — Programs, Sequencer and Global — but the XD now offers no fewer than 77, with many of these controlling important aspects of sound creation and control. When I reviewed the original, I wondered whether Korg would release an editor that would expose these in a simple fashion but, while there's now a librarian that allows you to order your Programs, insert user-programmed oscillators and effects, and create new micro-tuned scales, there's no editor; you still have to program things such as the performance controls, the velocity response and the LFO synchronisation through the menus.
Shift Functions
When I reviewed the original Minilogue, I asked Korg to silk-screen its Shift functions onto the top panel. But it never happened. Today, the XD has more Shift functions than the original (some of which you might use frequently) but they're still not annotated on the instrument itself. I doubt that you'll want to use a crib-sheet when programming what is supposed to be a simple hands-on synth but, with common operations such as selecting panel mode, tuning, storing and recalling favourites as well as adjusting some VCO, VPM, LFO and effects parameters, I think that it might be necessary.
Custom Oscillators & Effects
The USR mode in the Multi Engine contains 16 slots for third-party digital oscillators, while elsewhere there are a further eight slots for third-party modulation effects. Programmers can create these oscillators and effects using the software development kit that's now available on GitHub. Korg describe this as "not a neophyte-friendly high-level editor", and that's correct... if you've not programmed in C or something similar you're unlikely to be able to handle it, especially since Korg aren't providing any technical support for it.
As shipped, one of the XD's USR slots is pre-loaded with an oscillator called Waves. This comprises a low-amplitude sub-oscillator together with two primary waves that you can edit using the six parameters available in the menus. The first commercial oscillator is also available, but when I looked to download this, I discovered that it would cost me $29, so I didn't. Nevertheless, that's not an unreasonable sum if you're planning to make the XD one of your primary instruments. There's also a port of the Mutable Instruments Plaits oscillators available on GitHub, which could be rather exciting. Unfortunately, it isn't ready to load and play; you need to build it once downloaded, and this again is not for the faint-hearted.
Pros
- In many ways, it's a big analogue polysynth without the size or the weight.
- Its panel is well laid out and the controls feel solid and robust.
- Despite a number of voicing limitations, it's more flexible than you might think.
- It offers three cascaded effects sections.
- It can sound superb.
- It's attractively priced.
Cons
- Its non-standard MIDI CC map is a pain, and it lacks MIDI overflow.
- For some, its 'slim' keyboard will be a deal-breaker.
- There's no way to select Programs directly.
- You can't move sequences between Programs.
- No aftertouch... still no bloody aftertouch!
- It uses a wall-wart.
Summary
Despite borrowing much of its technology from the larger and more expensive Prologue, the Minilogue XD remains much more affordable than many four-voice analogue/digital hybrids from elsewhere. If its miniature keyboard and its non-standard MIDI implementation don't bother you, you'll find a lot here that's excellent.