You are here

Roland JDXi

Synthesizer By Paul Nagle
Published July 2015

Roland JDXi

Roland’s JDXi crams an awful lot of synth into a very small box.

Since last year’s launch of the Aira range, Roland’s musical legacy has been widely celebrated for its influence on popular culture. Not content to rest on past glories, the Japanese giant continues to fight for its rightful place in a market increasingly awash with analogue. The JDXi is a step in a new direction, a sub–£400$500 combination of technologies, rejoicing in the description ‘interactive analog/digital crossover synthesizer’. Apart from that being quite a mouthful, it’s immediately obvious there isn’t a whole lot of crossing over going on at this stage. The analogue component is heavily outnumbered: one voice against 128 of the shiny Supernatural variety. These resources are shared across four parts: two digital synths, drums and the (hybrid) analogue monosynth.

An onboard sequencer provides classic step– and real–time recording and helps define this diminutive keyboard as a credible musical sketchpad and live accompaniment machine. Present, too, is a vocoder and vocal transformer, while better–than–average effects complete a sonic toolkit scoped to leave rival small synths and grooveboxes in the lurch. It adds up to a serious package of high-end technology for the money, but how does it all hang together?

Toy Story

The JDXi is a portable, plastic performance synth in the Korg Microkorg or Novation Mininova mould. Whether these instruments succeeded because of their tiny keyboards or in spite of them we’ll never know for sure, but the compact (575 x 245 x 85 mm) JDXi follows in their footsteps by adopting mini keys — 37 of them. These are velocity sensitive and have a configurable response, but no aftertouch. Such a keyboard may well be adequate for sequencer recording and interaction, but it’s always going to be unwelcome to players happy with the traditional size. The teensy pitch and mod wheels won’t win many converts either, but the well–spaced knobs providing much–needed instant access to filter, LFO and effects fare better.

Less appealing are the buttons, especially the eight rubber imps camouflaged in black beneath the display. They really should have been bigger and bolder because not only do they select programs, they are essential to navigate the long (and mostly linear) menu system. Condemned to endless button–prodding, your lot is improved slightly by shortcuts and shift operations that generate larger or faster increments, but what is sorely lacking is a data entry encoder.

Keeping to the ‘Microkorg’ brief, a snake–like microphone bursts from the front panel to unleash yet more singing robots upon the world. Actually, it’s a good deal more flexible than that and, as well as the microphone socket, there’s a second input on the rear for line/guitar effect processing. When this is used, it overrides the microphone.

I welcomed seeing MIDI In/Out ports of industry standard dimensions and shape — so much so that I could almost forgive the lack of a dedicated Thru (soft Thru is available). There’s nothing miniature about the stereo outputs either, nor does the headphone jack conjure unpleasant thoughts of ‘earbuds’. Sadly there’s no sustain pedal input, but for recording piano parts or similar you might get by, at a push, with the panel’s ‘Key Hold’ button.

In common with pretty much everything Roland makes these days, the JDXi can function as an audio interface. A high–speed USB 2 connector provides this connectivity but doesn’t supply enough power to run the JDXi — you’ll need the supplied 9V adapter for that. Battery operation isn’t an option either. The USB implementation is rather neat in that it can switch between a generic (class-compliant) MIDI mode and ‘Vendor’, which uses Roland’s proprietary (two in, two out) Audio and MIDI driver.

Surveying the interface, you’re struck by several incongruities. Firstly, you notice that the dull red text on black background is difficult to discern in low light. Next, although most of the knobs are self–explanatory, you might puzzle over the single control marked ‘Envelope’. Experimentation reveals that it provides a continuous series of amplitude envelope overrides, progressing through short and snappy through to organ–like shapes, arriving eventually at a slow-attack, long-release ambient mush. However, the filter envelope isn’t tweaked in parallel, so the effect is often compromised, forcing you to grapple with menus. Lastly, even those who aren’t hung up on aesthetics might find the two–line amber LCD drab, the construction light and insubstantial, and the shiny plastic panel somewhat toy–like. Fortunately, looks aren’t everything.

Crossover Palaver

Whilst pondering truth, beauty and the JDXi’s ‘crossover’ nature, I started to wonder how far 128 digital voices would go. The number doesn’t represent absolute polyphony because it is divided up by Roland’s familiar ‘tone’ system, in which multiple waveforms are layered. Acknowledging that some sounds will consume more voices than others, I never once experienced a polyphony issue. This, despite playing large pads, dense drum patterns and two–fisted electric piano.

There are 256 preset programs (banks A–D) and the same amount of user locations (E–H). Having made a selection, you can freely modify all constituent parts then re–save to another location without impacting other programs. Unhelpfully, the synth always powers up at the first preset and, equally unhelpfully, the program name is only shown when you hold the shift key. Fortunately the ‘Favorite’ button is on hand to access 16 banks of 16 chosen programs directly — a much faster method than pressing Value buttons. The top line of LCD real–estate is reserved for the patch/bank number, tempo and the bar counter, whether the sequencer is active or not.

A program’s four parts each have a dedicated sequencer track and a path through the effects. A vertical column of buttons affords instant Part selection or, when the shift key is brought into play, track muting.On the JDXi’s back panel we find a  power input and switch, a  USB port and MIDI I/O sockets, a  line/guitar-level input switch and, all on quarter–inch jacks, audio in, stereo out and headphone sockets.On the JDXi’s back panel we find a power input and switch, a USB port and MIDI I/O sockets, a line/guitar-level input switch and, all on quarter–inch jacks, audio in, stereo out and headphone sockets.

Great, Smashing, Super

Before exploring the two digital synths that head the column, I should mention that only one at once can use the vocoder, otherwise they are functionally identical. For an introduction to the JDXi’s wealth of factory sounds, select a category using the large, slightly stiff, rotary switch. The offerings are: Vocoder/Auto Pitch, Brass, Seq, FX/Other, Keyboard, Bass, Lead and Strings/Pad, although some contain unexpected inclusions. For example, Keyboard is where you’ll find guitars, harps and sitars, while ‘FX/Other’ houses orchestral hits alongside weird noises.

There are a total of 256 preset tones for the digital synths, but it’s no hardship to audition so many because the quality is consistently high. The stunning renditions of orchestral strings, synth basses and choirs caught my ear at once; while there isn’t a regular acoustic piano, the punchy JD Piano and Electric Grand are both more than serviceable, the various electric pianos are fab too. Still, no matter how playable these all are, they only represent the tip of the iceberg.

There’s nothing wrong with selecting tones and making basic tweaks with the panel knobs, but sooner or later you’ll head for the ‘Menu/Write’ button to see how deep the rabbit hole goes. With 10 top–level entry points (11 if you count ‘version info’), the menu system covers every major area of the JDXi, including global or system functions such as MIDI sync and metronome behaviour. Some pages contain program–specific data (eg. the tempo, part levels and effects routings), but by far the most heavily populated menu is Tone Edit. Once in there, the squishy Cursor and Value buttons can expect a thorough workout, especially since a part consists of up to three layered tones, all which can be edited independently.

Roland’s designers have crammed a  lot of controls into the JDXi’s 57 x 24 cm front panel. Roland’s designers have crammed a lot of controls into the JDXi’s 57 x 24 cm front panel. Roland’s Supernatural synthesis is the basis for all the expected virtual analogue waves, plus Supersaw and PCM–based sources. Each tone has an envelope for pitch, filter and amplifier (one stage per page) and perhaps due to limited screen space, the 160 PCM waves aren’t shown as names, only as numbers. For convenience, it could be worth printing a few sheets from the downloadable Parameter Guide, which shows the full list.

Having chosen a sound generator, your source may be processed by seven types of filter including four low–pass filters with a choice of 12dB or 24dB modes. Backing up the primary choice there’s always a high-pass filter on hand to thin things out. Without getting too sidetracked by all the options, suffice it to say that this is a superior–sounding synth engine with qualities that almost transcend the cumbersome menus. I’ve never liked adjusting envelopes one stage at a time, but at least these have some useful extras in the form of loop points and a tempo-sync function.

Different Drummer

The menu trawl continues into the Drum part. Indeed, there are so many parameters that kit production could become an obsession, not that there’s any urgency because the 33 factory kits are, without exception, wonderful. It’s obvious Roland have been listening closely to their old machines because represented in all their glory are the TR606, TR626, TR707, TR727 and CR78 alongside their more famous siblings, the TR808 and TR909. You won’t go far wrong with the selection of genre–specific kits either.

A kit consists of 26 voices and, if the lighting is right, you might even spot their names printed in faint grey above the keys. Each voice can be set to single or multi play, with the latter denoting that multiple hits are allowed; a useful feature for cymbals and other instruments suited to an accumulating decay.

Every voice has up to four wave generators, whose output can be independently panned to create a complex stereo instrument. For the more experimentally minded, individual waves can be randomly thrown around the stereo field, or switched from left to right on alternate hits. Supplementing this extravagant panning are tools to define the wave’s velocity range and to specify a desired behaviour for velocities outside the range. By now it won’t come as a surprise to learn that each wave can be extensively transposed, filtered, envelope–shaped and tossed into the effects processors.

When considering drum kits and the effects, there’s more to play with than first impressions suggest. If you want a load of reverb on your clap, a bit less, plus delay, on the hi–hat, distortion on the first kick but more distortion plus flanging on the second, all are achievable on the JDXi. As a further example of the level of detail within a kit, no fewer than 31 mute groups permit sophisticated interaction between voices: far more than the usual open/closed hi–hat or conga muting.

Analogue Retention

Which brings us to the analogue synth, or more correctly the analogue oscillator, sub-oscillator and low–pass filter set in an ocean of software. I was unable to uncover whether we’re talking VCO or DCO (my money would be on the latter), but its output involves familiar waveforms triangle, sawtooth and variable square. A petite Monotron–like knob is on hand for direct access to the pulse–width, but the range on the review model didn’t extend to really thin pulses, rendering it impossible to create the fine, reedy tones we know and love. And while pulse-width adjustment is as accessible as the word ‘analogue’ deserves, it takes numerous menu hops before you can introduce pulse–width modulation.

The sub-oscillator is unusual in responding to any PW or PWM tweak. It’s equally unusual in being at a fixed volume, either on or off. Here’s where an optional thinner pulse might have helped because sometimes ‘on’ was a bit much. The sub is available at one or two octaves below the main waveform and there’s no doubt it adds extra beef to an oscillator that’s sweet enough, if not quite so full and inspiring as, for example, a Roland SH101’s.

No information was forthcoming about the analogue LPF, but a quick fondle of the cutoff and resonance suggested this to be a 24dB filter, and a decent–sounding one at that. It’s also slightly steppy and possesses a dominant resonance on a par with the System 1’s ACB filter. Roland inform me that the review model is a late-stage prototype and that the stepping is one of several issues already resolved. Personally, I’d love to have heard the filter overdriven, or frequency–modulated by the oscillator, but such fripperies are beyond the simple bleep and squelch remit — and maybe beyond DIY hacking too. Ultimately, the JDXi’s capacity for ‘real analogue bass lines and solos’ will satisfy many users.

Pattern Sequencer

I hope the term Pattern Sequencer doesn’t bring false hopes of a free pool of patterns to fool around with. It’s strictly one four–track pattern per program. All tracks share scale settings (ie. timing resolution) and are of equal length (between one and four bars). If you switch programs during playback, the next program’s pattern takes over smoothly at the end, with delay repeats continuing without interruption, as it should be.

With a maximum of four bars to play with, your scope for recording elaborate keyboard riffs isn’t huge, but if you opt for a scale setting of 32nd-note divisions then halve the tempo, it’s possible to imagine there are eight bars. The sequencer capacity isn’t stated, but if you record too much data, warning messages demand you hit ‘Exit’ before you can proceed.

Apart from its step buttons and flashing tap-tempo, the sequencer isn’t the most visually stimulating. The current beat and number of measures take pride of place on the display, but there’s no obvious way to make the bars scroll automatically for editing. More seriously for an ‘interactive’ synth, several important commands cannot be executed while the sequencer is running. In particular, a program can’t be saved nor can an iffy chord be fully cleared from a step without first stopping. Adapting to these limitations is essential if you’re going to enjoy the JDXi experience, but in its defence I’d argue there are plenty of reasons to make the effort, not least if you relish having three classic Roland recording methodologies in a single box.

Of all the recording tools on the shelf, ‘TR–Rec’ is universally familiar thanks to certain legendary drum machines. The strength of this implementation is in its simplicity: select a voice and then enable steps with the 16 backlit rubber keys. In performance, your speed is hampered slightly by having to locate the shift key in order to select the bar to edit — a bit of a stretch for one–handed operation.

Real–time recording is ideal for capturing drums or regular keyboard parts, subject to the current pattern resolution. Regardless of the inherent quantisation, recording this way is a blast and a major boost to the JDXi’s performance credentials. You can also capture the movements of panel knobs, but here the manual warns the pattern might fail to keep up if you record ‘extreme knob movements’. This is especially likely if you get carried away with envelope tweaks or filter sweeps for individual drum voices.

Put it down to my lingering adolescence if you like, but I found it far too easy to stray into ‘extreme knob movements’ and often hit the ‘Pattern Full!’ or ‘Rec Overflow!’ warnings. If you’re not afraid to really stress the poor thing’s processor, you can activate the transmission (and therefore recording) of all menu–based edits. Despite the resulting glitches and warnings, recording tweaks can bring a pattern to life, so it’s to be hoped the issues can be addressed, or at least improved. My last observation concerns the recording of effect adjustments. Since these aren’t linked to any specific track, they aren’t cleared when you erase the pattern data. The suggested workaround is to re–record, but I’d like to think a better solution for wiping them can be devised.

Step time is the third means of producing sequences and it’s almost exactly as it should be: fast, intuitive and fun. Notes are entered as per the Roland JX3P many moons ago, with chords, ties and rests added to each step. Surpassing that venerable synth, velocity can be captured too, and since you can effortlessly slip into real–time recording and add filter sweeps or LFO wobbles, the sequencer is ideal for lovers of dripping acidic patterns. Its main drawback in this respect relates to the fixing of all tracks to equal lengths, which cruelly rules out the odd–lengthed, polyrhythmic patterns so typical of the JX3P and SH101.

There’s one final area in which the JDXi falls short of its groovebox aspirations: there’s no convenient way I could see to mute/unmute individual drum voices. One way to achieve it is by selecting a voice and quickly grabbing the level knob, but that’s far from ideal.


After enjoying the sequencer, I continued to reminisce fondly over SH101 functions, turning next to the arpeggiator. This is complete with a physical ‘hold’ button even though the rest of its options are menu-based. Arpeggiators represent another form of automated jamming, here restricted to a single part at once. The usual up, down and random directions are offered, but there are 128 preset patterns built in too, full of slidey bass lines, sequences and the like. There aren’t any drum–specific versions but, nevertheless, a ton of variation and fill mileage is at your fingertips by simply muting the drum track and letting rip with arpeggiated noodles.


In choosing an effects implementation, the JDXi went for quality over quantity with just four simultaneous effects. Every part and each individual voice in a drum kit can be processed, with a fair amount of finesse, through the two insert and two send effects, even if not every permutation is possible.

The first effect is generally intended to big–up or nastify your signal. I might ordinarily skip past its distortion, fuzz, compression and bit–crushing, except that I got hung up on the distortion for quite some time. Unlike most synth distortion algorithms, this one doesn’t set your teeth on edge and it revealed further gritty appeal once I checked out the scope for customisation. It transpires that all the effects are well–stocked with programming options under the hood; for the distortion alone, there are six different flavours, plus adjustable drive amount and presence (high–end response).

Next along you find a choice of flanger, phaser, ring mod or ‘slicer’, of which only the ring mod was disappointing. The phaser is a warm, rich bath of swooshiness and the slicer chops up the signal rhythmically, ready for your next euro dance hit. Anyone hoping for a classic Roland chorus shouldn’t abandon all hope either — the flanger becomes quite chorusey with its feedback set to zero.

The final two effects are traditional send effects. Both delay and reverb are clean, professional–sounding and fine–tunable, to an extent. It’s a shame the main panel sports just a single depth control for each, but when you consider the rewards it’s not a massive inconvenience to rely on menus for setting the reverb type, the delay’s feedback and so on.


For many years and despite countless pleas, Roland have been resolutely ‘not getting back into analogue’, which is why this little ‘crossover synth’ has been such a pleasant encounter. It shouldn’t be a surprise that the digital components take all the honours; the JDXi’s strength lies in its Supernatural synth engine and in its highly malleable drums. But such complexity comes at a price, and I found programming via this particular menu system about as enjoyable as eating soup with a fork. Roland don’t have an editor in the pipeline right now, but are considering the idea — a potential game–changer in my opinion.

The massive voice count makes a real difference to pads and typical ‘workstation’ keyboard parts, all of which the JDXi handles like a dream. Although only four–part multitimbral, this doesn’t feel limiting, but it is rather sad that the analogue synth is not bolder and more fully featured. If that earns only a lukewarm reception, the keyboard leaves me positively cold, but admittedly it keeps the overall size to a minimum and it’s certainly up to the job of building sequencer patterns and tapping in drums. True, having to stop the sequencer before saving imposes limits on spontaneous song development, but otherwise the sequencer has bags of potential thanks to its varied recording methods.

Summing up, the JDXi is an affordable, well–realised blend of synthesis, drums and sequencer. It’s not the most sturdy instrument ever made, but it’s a highly portable groovebox full of sounds you’ll never be embarrassed to perform or record with.


I can’t think of much competition in the same price bracket but thanks to its sequencer, polyphony, multi–faceted synthesis and effects, the JDXi feels more like a padless alternative to Korg’s new Electribe than it does to physically comparable keyboards such as the Korg Microkorg XL and Novation Mininova.

The Voice

Text on the front panel suggests you should see the owner’s manual about ‘Mic’, but I’m sure you’ve worked out this refers to the included microphone. Previously I was captivated by the VT3 Vocal Processor, so it’s exciting to see some of its vocoding muscle lodged within the JDXi. The vocoder must be fairly resource–heavy because its use disables the analogue synth, but as vocoders go, it strikes a good balance between ease of use and clarity. Favourite presets include the choirtastic ‘VP330’ and ‘Robot’, for those all–important Man Machine moments.

There are alternate uses for the snaky appendage too, in the form of Auto Pitch. Primed with a set of major and minor scales, it improves on typical pitch-correction by throwing in temporary gender reassignment too, courtesy of octave and formant shifts.

Lastly, and for sheer novelty value, press the Auto Note button and notes will be generated by microphone input with no need to touch the keyboard. My vocalisations tended towards the wild and erratic at first, but as the process even works for drums and the analogue synth, I had a ball anyway.


  • A compact, high-quality sketchpad or jamming companion at a tempting price.
  • Generous polyphony.
  • Deep, lush and rewarding digital synthesis and superb–sounding drums.
  • Well–implemented effects.
  • Sequencer offers three classic recording methods.


  • Several important functions demand the sequencer stops.
  • The user interface isn’t suited to a synth engine this complex. Would be more appealing with a software editor.
  • Tiny keys and general flimsiness.
  • No battery option.


A small, lightweight synth with an impressive sound palette, monster drums and a whiff of real analogue. Despite mini keys and lengthy menus, the JDXi’s sequencer, effects and signal processing options add up to an impressive instrument for the money.


£379 including VAT.

Roland UK +44 (0)1792 702701


Roland Corporation US +1 323 890 3700.