Roland Jd-Xi (2015)

Roland Jd-Xi

 
UNDER THE HOOD
Inside Roland JD-XI

Inside Roland JD-XI

Inside Roland JD-XI

Inside Roland JD-XI

Inside Roland JD-XI

Inside Roland JD-XI

Inside Roland JD-XI

Inside Roland JD-XI

 
MAIN DSP, ELECTRONICS, CHIPS PDF DOCUMENTS

IS42S16400J
IS42S16800F

S29GL_256S
AK4556VT
FM3_MB9AF1A1M JRC_4580
JRC_2082

 

IMPRESSION

Here’s what will probably become my favorite synthesizer: the Roland Jd-Xi. A pure marvel ! Released in 2015, the JD-Xi encompasses a synth capable of releasing magnificent sounds as well digital as analogue, as well as allowing us to use drum sounds coming from 32 iconic beatboxes. The digital part has a polyphony of 128 oscillators (a tone, which is a basic sound, can consist of 1 to 3 oscillators) and the analog part comes only in a monophonic mode.

Let’s start with the analog part

The Jd-Xi is a synth that Roland describes as hybrid, it has a digital rendering engine based on superNatural technology, as well as a truely analog part. This analog part is composed of a VCO made of one oscillator (3 possible waveforms: triangle – sawtooth – rectangular adjustable) but also including a sub-oscillator which will play a square wave (or rectangular wave) one octave below, or even two ! So, we’ve got a VCO pretty similar to what we find on a venerable Juno-6. The pwd/rectangular waveform can be modulated by the LFO, in a very conventional way. The modulation parameter will also apply to the sub-oscillator, in fact.

This oscillator is produced truely using analog circuitry. Then comes the classic VCF section, also truely analog. This filter is based on the « transistor lader » technology and not the « diode-lader » (which was the classic technology that Roland used at the time of its production of analog synthesizers). I really enjoy this filter enormously because I find it « creamy » absolutely not aggressive or incisive. It is very soft, very warm. The resonance can rise to degrees very close to self-oscillation. On the very first synths produced, the firmware contained an inappropriate setting that made some obvious « aliasing » phenomenons in the various levels of filter settings. This phenomenon has disappeared with recent firmware versions (1.02 and 1.10). The analog filter has a single LPF mode (which seems to be a 24dB mode).

There are two envelopes (including the four classic parameters: ADSR) handling the sound, the filter envelope and the volume envelope. Those envelopes are managed by the digital part of the synth. But frankly this is not what will blacken the picture. Then there is an LFO (only one unfortunately) which is also managed by the digital part, but very complete (with a fade-in parameter, and which can simultaneously control the pitch – the filter and the volume of the sound). There are still some global parameters, but basically we are facing of a kind of monophonic Juno-6/60, with however, a more advanced LFO as well as a dedicated filter envelope. The sound obtained during my tests proves to be both stable, very hot, and round. There is the Roland signature, but it doesn’t really sound close to an existing signature …

One may regret the monophonic aspect of this analogical part, but it is not excluded that, maybe in the future, different synthesis cohabit more and more within the same machine. Nevertheless with a monophonic voice, we can realize nice things, FX, basses, leads,…

The digital part 

The JD-Xi digital sound engine part is based on the superNatural technology that Roland has already developed few years ago and implemented on some models, quite famous, like the Jupiter-80, the Roland FA or the Integra-7. This technology is based on PCM sounds (samples therefore) but algorithms calculate in real time the variations of harmonics in function of parameters allowing to emulate a very high degree of realism without having to use the classical « loops » within the PCM sounds. The sound is thus computed using DSPs and constitutes a living matter. In the case of the JD-Xi, the goal is obviously not to simulate classical instruments (there are some but they are not of a particularly striking quality) but to allow 2 categories of sounds.

The 1st one is based on analogue synthesizer waveforms, and includes the classic triangular / saw-tooth / sinusoidal / rectangular and the Super-Saw waveforms. These sounds have the particularity to be modeled like a classic V.A. engine. We also have parameters (for instance the analog feeling) which allows to insert a form of random variations in the sound to make it less smooth, less linear. There is also a dedicated detuning parameter for the « super-saw » waveform, which allows you to detune the seven sawtooth making the super-saw to create an extremely rich and ample sound.

The 2nd one is based on purely sampled waveforms as choirs, basses, guitars, percussion sounds, strings, pianos, fx, … Of course on these sounds some previously mentioned parameters do not apply.

Then we have a 5 modes filter (LPF 12/24, HPF, BPF, Notch). These filters are very musical I must say. No « screaming/hissing » phenomena to report or other digital artefacts that can sometimes be encountered on other machines. To control this filter section, there is a classic ADSR envelope as well as a keyboard transposition parameter and a velocity factor. We could regret to only have a single filter per « part » (the Waldorf Blofeld and the Novation Ultranova propose a structure with two filters that can be coupled according to different schemes), but it must be remembered that a sound may be composed up to 3 parts ! This, very frankly, will create complex sounds of extreme richness, if needed !

Then comes the amplification part. Nothing special here either … There’s a classic ADSR envelope, a velocity factor and an overall volume. 

What is called the « modulation matrix » is ,here, reduced within the JD-Xi synthesis. It is possible to have an LFO (only one unfortunately, as for the analog part) which can be assigned to the part « Pitch », « Filter » or « Amp » of the synthesis engine. This LFO can be synchronized to the tempo, can be restarted with each key press, and also has a fade-in parameter (progressive increase in the amplitude of the LFO).

A digital sound is composed, as I said, of 3 « parts », which means that a sound can be made up to 3 DCO/PCM – 3 filters – 3 DCA … My small regret is to have only a single LFO. Without especially the need to use at least 3 LFOs that we find on a Novation Ultranova, having two LFOs would have been interesting (one could change the stereo panning of a sound, very slowly for example, while the 2nd LFO rather fast could change subtly the pitch of the oscillators). This is strongly similar to the sound design architecture found on the Roland JX-305 but which can include up to 4 « parts » to create a sound.

The FX
 

Here are two multi-effects for various uses, and also a delay and a reverb. The 1st multi-effect is « distortion /compression » oriented. The 2nd one is « modulation » (flanger/phaser/ring modulation/slicer) oriented. However, and inexplicably, we don’t find any chorus! Depending the selected effect beeing edited, there will be 3 to 6 parameters. The delay can be adjusted to the tempo also (fortunately). All those FX sound very good to me. The different reverb programs are also pretty convincing. The way to set them is global for the same program. Only the send and return levels are adjustable for each of the sound sources (the 2 digital parts, the rhythm part and finally the analog part).

Memory organisation structure.

The Jd-Xi is a bit special in that it does not really have a bank of « tones ». Instead, it has a program bank. A program includes the 4 sound sources, various global parameters (arpeggiators, tempo, …) as well as the effects settings. If it is easy to access to the factory tones to create your own program, it becomes more complicated to use tones that you created yourself in new programs (which are stored from E01). The absence of a bank of tones will make it necessary to use a « copy and paste » function which will allow you to search for a tone from a specific program (source) and copy it into the desired program (destination) . This is not very clearly explained in the manual, I imagine that many people will find themselves lost a bit if they want to use a super analog sound they stored in the E10 memory for instance, and they now want to use in another program, E15 for instance … With a real « tones » bank clearly accessible and independent from a « programs » bank everything would have been simple.

Managing import/export sounds to a computer.


At the opposite, here it is really very simple. A simple USB connection, as well as the press of a key at the boot up of the synthesizer makes it very easy to import / export from / to the memory of the Jd-Xi. A bit similar to the Roland JP-08 system.

Rythmic Part 

The Jd-Xi has hundred of samples from « legendary » rhythm boxes (TR-808, TR-909, TR-626, CR78, …). This section has its own synthesis engine (which is therefore not the same as the synthesis engine used for the two « synth-digital » parts, already mentioned). This section makes it possible to apply filters, envelopes, LFO, … on the various sounds that will be mapped on the JD-Xi keyboard… keyboard that includes inscriptions allowing to organize efficiently the storage of sounds. Note that just like the two parts « synthesizers-digital », turning the controls of the main panel will modulate the drum sounds. These changes can be transmitted to the JD-Xi internal sequencer (or to an external sequencer). There are 33 already programmed factory kits that should cover almost all needs … for a total of 453 samples (PCM) ! Pretty huge ! It should be noted that a single drum sound can itself be composed up to 4 « parts » … This lets imagine the almost infinite possibilities of creations of percussion sounds !!

Patterns sequencer
 

I’ve never been a big fan of built-in synthesizer sequencers. Whether it’s the Roland JX-305 (very complete), the Korg M1, the Yamaha SY-77 or the Roland W-30, I always use a computer-related sequencer. Probably a question of pure habit and flexibility. So I have not explored the possibilities of the Jd-Xi very deeply. At the first glance, it’s rather a sequencer allowing to perform one to four measures, and with a certain « pattern » behavior (as opposed to the song mode of some advanced sequencers). A kind of sequencer memory will therefore be available for playing 4 measures in loops. This sequencer also memorizes the movements of the controls on the front panel. Be careful, however, that depending on the number of notes, events, etc. entered, an error message could be displayed telling the memory is full. This sequencer seems to me very « groove / pattern » oriented but can not really be compared to a real sequencer. Even though there are some editing functions, quantization, and erasing. Nevertheless it is thanks to this small internal sequencer that one can play the 4 parts (2 digital syntheses, the rhythm part, the analog synth) that compose a program. This small sequencer is therefore a sequencer with 4 tracks and will therefore allow to play simultaneously two digital synthesizers, an analog synthesizer and a rhythm box! These 4 parts have a pre-programmed midi channel, and this will have to be taken into account if the Jd-Xi is used from an external sequencer. The two digital synthesizers use channels 1 & 2, the analog synthesizer uses the channel n°3 and the rhythm part uses the channel n°10.

The Jd-Xi for which usages ?

Most certainly for a lot of different uses! It’s a master in sound research. The many parameters available for digital synthesizers, as well as the very large range of PCM sounds in memory, will enable you to create sounds of any kind, from the warmest and mildest to the coldest and aggressive, through atmospheric sounds or impressive specials effects. Its truly analog part will also make it possible to add an indisputably attractive element to the whole. Although monophonic, one can create extremely deep and beefy leads. By mixing (via an external sequencer) both digital sounds and analog sound, you can create extremely rich and sophisticated sounds !

We can also use this synthesizer as a « groovebox » thanks to its small sequencer integrated with 4 tracks. Nevertheless, we’re very far from the possibilities of a JX-305… But these are two machines designed for very different needs.

Finally, the Jd-Xi can also be used as a vocoder effects (like the Korg microKorg or  the Novation Ultranova) (I did not mention it because I do not use this feature … at least not using a synthesizer). I’ve not tested yet this possibility (the microphone supplied with the Jd-Xi is still packed in its box).

Under the hood ?

Once opened, we find a small motherboard containing both the analog and digital part of this synthesizer. The analog part seems to be composed of many small « CMS » components (transistors, capacitors, …) and which probably provide the circuitry needed for the oscillator and filter part of the JD-Xi. The digital part takes up most of the circuit board and is composed of several important components: first there are several circuits of DRAM and flashram for a total of 40MB. There is a large Roland DSP (Roland R8A82021ABC) which is certainly the heart of the digital sound production system (this DSP is found on many other Roland synthesizers, probably a rationalization software development process is used at Roland). An ARM microprocessor (FM3 MB9AF1A1M) can also be found. It is perhaps the responsible chip for organizing the operation of the system, and its subsets. Finally, there is a bunch of small amplification circuits (JRC 4580, 2082) and D/A conversion (AK4556VT).

Note, the very good initiative to have a 2nd pcb board dedicated to the audio outputs, headphone, and microphone input.

Overall conclusion & personal opinion
This little synthesizer is fantastic and absolutely unbeatable, especially at this price, to compose a very varied range of different sounds, ranging from its pure analog voice, passing by other digital sounds sometimes emulating to the perfection the warmth of analog sounds, or able to create some very cold or aggressive sounds too. It has a great range of interesting effects (however so sad to have omitted the chorus, … yet very common), a well designed arpeggiator, and a small 4 tracks sequencer. Not to mention the possibility of using it in the vocoder mode !

The possibilities of this synthesizer (especially do not pay attention to the size of this small machine) are absolutely huge! With a very large polyphony (up to 128 « parts » simultaneously .. a sound composed from 1 to 3 parts … and depending how many drum sounds are also played, the polyphony will be very variable, but nevertheless vast), an enhanced digital engine, a real analogue engine, a well-stocked rhythm section, direct-access controls on the front panel, a well-designed arpeggiator, a small 4-track sequencer Integrated, a vocoder, and a USB connection … for less than 500 euros, … I think Roland hit very very strong !

I only regret the small size of the LCD screen (as for the JX-305, only 2 lines of 16 characters while there are hundreds of editable parameters). It will therefore be necessary to juggle enormously with the editing buttons to display a specific menu, or to search them in a linear way … Unless we can try to memorize the 20 shortcuts to save a bit of time. Above all, the absence of a small rotary « alpha-dial » which would have simplified many things!
To stay on the cons side, i’ve to mention the mini-keys that are definitely not my cup of tea (but you can always control the Jd-Xi using a real keyboard controler) and maybe the missing of 4 small controls on the front pannel that would have allowed to directly manipulate the envelope parameters. But for such a price, and when we see all the possibilities, one can frankly not complain … this synthesizer is a small wonder