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Roland D20

LA Synthesiser

Roland's latest keyboard combines two currently important concepts: the workstation and the company's own Linear Arithmetic synthesis. Simon Trask test drives the "multi-timbral linear synthesiser muhitrack sequencer".

Roland's D20 is the latest synth to adopt the workstation approach. But is it really The Complete Instrument?

THESE DAYS IT seems that an instrument's packaging is almost as important as its sound. Providing a flavour to suit every taste is sound business sense.

Take Roland's latest instruments to use the L/A synthesis introduced on the D50: the D110, D10 and D20. All three instruments are essentially the same but presented in different guises to suit different requirements.

The D110 (reviewed last month) is an expander intended to offer all the things musicians and studios found wanting on the company's multi-timbral MT32 L/A expander - 19" rack-mounting format, front-panel programmability, battery backup of user sounds, and individual audio outs. If you already have your full quota of keyboards, the D110 could be just what you're looking for.

The D10, on the other hand, is intended for keyboard players who use external sequencing, while the D20 is the same instrument but for the addition of an onboard sequencer and disk drive - the all-in-one approach for the musician who doesn't have an external sequencer. Like I said: a flavour to suit every taste.


ROLAND DESCRIBE THE D20 as a "Multi Timbral Linear Synthesiser Multi Track Sequencer": dedicated followers of instrument fashion will probably prefer to call it a music workstation. This one has a 61-note keyboard which is sensitive to attack velocity but not aftertouch (nor can the D20's sounds respond to aftertouch). The synth is multi-timbral and has an onboard digital drum machine, an onboard digital reverb, an onboard sequencer and an onboard disk drive. Notice the onboard bit: we're talking living in a box, here. But is this integrated approach really able to provide, in one instrument, all the music-making power that today's musicians require?

Essentially you can use the D20 in any one of three modes: Synth, Rhythm and Sequencer, each accessible from a dedicated front-panel button. Each of these modes can also be set to either of two configurations: Performance or Multi Timbral. The former allows you to play a Patch (which consists of one or two Tones, organised in whole, split or dual modes) on the keyboard while the latter gives you access to eight independent Timbres (each consisting of a single Tone) which can be played multi-timbrally from an external MIDI device or internally using the onboard sequencer. The D20 provides you with 128 Preset and 64 Programmable Tones (of course you can edit the Presets and store the results in the Programmable memories).

For those of you who are a little rusty on your Linear Arithmetic synthesis (which, incidentally, is an all-digital system), a Tone consists of from 1-4 partials, each partial being either a synth waveform (sawtooth or square) or any one of 256 PCM samples. Each pair of partials (1&2 and 3&4) an be assigned a Structure which, essentially, determines what combination of synth and PCM partials to use; at this stage you can introduce ring modulation of the partials.

A PCM partial can have its pitch modified by a single LFO and a pitch envelope, while its TVA (Time Variant Amplifier) level an be modified by an amplitude envelope. To this configuration a synth partial adds a TVF (Time Variant Filter) section with cutoff frequency modifiable by resonance and filter envelope, and pulse-width modulation of the square wave. D50 owners will notice that this is a slightly simplified version of the D50's Tone architecture. (For a fuller explanation of L/A synthesis, refer to the D50 review in MT May and June '87.) Incidentally, while the D20's front-panel access to editing isn't too labour-intensive, you might still like to check out yet another of Roland's plug-in programmers - in this case the PG10, which is compatible with the D110, D10 and D20.

The D20's Rhythm mode gives you access to 32 preset and 32 programmable one-bar rhythm patterns. You can select these in real-time in any order, record the programmable patterns, and play on top of these patterns using either the D20's 63 onboard PCM percussion samples (known as Preset Rhythm Tones), the currently-selected synth Patch (in Performance mode) or any of eight Timbres (in Multi Timbral mode). Up to eight Tones an be sounded simultaneously in each rhythm pattern, while a maximum of 96 notes can be recorded per pattern.

The onboard sequencer has nine tracks and an store approximately 16,000 notes (pre controllers). Tracks 1-7 an play a single Tone, track eight an be either a synth or a rhythm track, while track nine is a dedicated rhythm track. Incidentally, the D10 has the dedicated rhythm track as well as, of course, the 64 rhythm patterns.

The maximum length of a sequence is 500 bars, though by selecting a time signature of 8/4 you can effectively record up to 1000 4/4 bars (assuming you don't use up all the memory first).

But multi-timbral capability is ultimately at the mercy of an instrument's polyphony. The D20 can play up to 32 partials simultaneously, its actual polyphony depending on how many partials are assigned to each Patch or Timbre that it's playing. For instance, if you're playing a one-partial sound you've got 32-voice polyphony, but if you're playing a four-partial sound that figure is reduced to eight voices. When you're in Multi Timbral mode and using Timbres with varying numbers of partials, the actual polyphony is free-floating. It's worth bearing in mind that each sounding Preset Rhythm Tone counts as one partial, while of course the Programmable Tones in the Rhythm Setup can be from 1-4 partials.

With the MT32, Roland introduced a feature known as "partial reserve", which allowed you to reserve voices for a specific musical part in a multi-timbral context. The D110 has this very sensible feature, and according to the D20's SysEx memory map it has the feature too - but there's absolutely no way of accessing it from the synth's front panel. Why oh why, Roland?

The onboard disk-drive (atop which you'll find the latest fashion accessory: a moulded disk tray) takes 3.5" DSDD floppies and can store approximately 35,000 notes. There are four file types: Song, Sound, Rhythm and All (the latter saving the complete data of the D20). You can, of course, format disks onboard the D20 (this takes a lengthy 150 seconds), and update and delete files. At one point in the manual there appears the sentence "It takes quite a long time for data to be saved". I think I'd second that.

Using an M256D RAM card you can save 128 Patches, 128 Timbres, 64 Programmable Tones, 32 Rhythm patterns, one Rhythm track and one Rhythm Setup (see later). Additionally you can transfer complete sound and rhythm data (but not sequence data) via MIDI SysEx.

THE D20 COMES with a healthy number and variety of sounds. Between the Patches and the Timbres you've got 256 sounds, though remember that these are drawing on 192 Tones, each of which are made up of a combination of synth and PCM sounds.

The D20 has 256 PCM samples divided into rhythm, attack, sustained, decay and effect categories. The rhythm samples (which for some reason are included twice, the second grouping not being affected by master tuning) are not the same as the Preset Rhythm Tones.

The attack samples concentrate on providing the attack envelope segments of all manner of instruments. These are the reason why everyone got so excited about L/A synthesis in the first place: the fact that you could combine synthesised sounds with the realism of actual instrument attack samples (always the most difficult stage to recreate, but precisely the one which gives a sound so much of its character).

The sustained samples are looped sustain segments, again covering a variety of instruments such as organ, sax, trumpet, trombone, electric piano, female voice and harpsichord - an attempt, methinks, to edge into Kawai K1 territory. The decay samples, which are labelled 'shot 1-16', are basically noise samples, while the effect sounds are loops of individual or grouped samples. Altogether these samples provide a wide range of sounds to be mixed with one another, mixed with synth waveforms or used by themselves.

The type of sounds that come with the D20 will be familiar enough to anyone who's ever used an L/A instrument There are plenty of delicate, shimmering bell-like sounds, a variety of tuned and ethnic percussion sounds, breathy choirs and flutes, bass sounds which can be fat and raspy, rich and warm or bright and sharp, warm phased electric piano sounds which'll melt you in seconds, harsh and metallic electric pianos, bright and punchy synth brass, the usual excellent range of organ sounds (church, Leslie, Hammond and shades in between)... I could go on. But it's also true that not everything in the L/A garden is rosy. Overall I'd say that solo strings and brass are not the D20's strong point, the strings in particular often sound thin and electronic. And, on the whole, the ensemble string sounds don't quite seem to cut it, either. But maybe these are just my own preferences.

Still, it's worth bearing in mind that, despite the sample snatches, the D20 is ultimately a synthesiser whereas, to my mind, Korg's recent M1 synth manages a much more successful hybrid of sampled and synthesised sounds - and also, to my mind, manages much fuller synth textures, though not necessarily warmer ones (I think perhaps the D20 wins out here).

One point worth making is that the D20's L/A sounds work well together in a multi-timbral environment. The quickest way to hear this is to listen to the inbuilt ROM sequences, which have been specifically designed to show off the synth in a variety of musical styles (you've just got to listen to number eight, 'Dinner Set').


YOU CAN SELECT from eight onboard digital effects: small and medium rooms, medium and large halls, plate, and three delays. Additionally you can set reverb/delay time and effect level.

Each Patch can be given its own programmed effect, while in Multi Timbral mode you can program one effect for all the Parts. Fortunately you can turn the effect on or off for each Part (in the case of the Rhythm Part, for each note/Tone), but unfortunately you can only set a global effect level. Incidentally, when you select the Rhythm Setup in Performance mode it adopts the effect programmed for the current Patch - so if, for instance, your Patch is using delay then so will all your drum sounds.

There are two tricks you can perform, however. One is to incorporate Programmable Tones into the Rhythm Setup or into individual tracks which use repeat-loop PCM samples, thus giving the impression of a delay effect alongside reverb (on a snare sound, for instance). The other is to pan all effected sounds to one output and all non-effected sounds to the other output, routing the latter through external effects.

At this point I should mention that, unlike the D110, the D20 doesn't have individual outputs. Quite why D20 owners should be any less likely to want them than D110 owners is beyond me. After all, the D20 makes it possible to sequence a complete piece of music and record the results onto two track. But if you want external EQing and processing, not to mention mixing (automated or otherwise), you'll have to put each part down on multitrack first.

"If sequencer tracks are active locally they won't play over MIDI but if you mute a track it automatically plays over MIDI - so you can't layer internal and MIDI'd sounds."

D20 Rhythms

THE 'RHYTHM MACHINE', as Roland call the rhythm section of the D20, has 32 eminently-usable preset patterns, consisting of 8-beat, 16-beat, disco, shuffle, reggae, pop and jazz rhythms along with such perennial Latin American favourites as the mambo, bossa nova, samba and merengue. Fans of today's dance music might wonder what happened to funk, hip hop, go go and house in this lexicon of rhythms. Considering the popularity of Roland's own TR909, 808 and 727 drum machines - and now, of course, the newly-rejuvenated TB303 Bassline - in contemporary dance music, it's quite ironic that the D20's preset rhythms scarcely acknowledge the '80s. Someone really should take Roland's staff out clubbing.
The sounds themselves are clean, bright and punchy. What you get for your money are standard rock and Latin sounds. There's nothing wrong with that, but considering you get a generous 63 rhythm sounds it's a shame Roland didn't widen the scope a bit. After all, we're living in an age in which people are exposed to a great diversity of percussive sounds.

The D20's 63 Preset Rhythm Tones can be mapped onto the keyboard along with Programmable Tones - a great feature which allows all manner of synthesised sounds to be incorporated into a rhythmic pattern-based context. Each note in the range C1-C8 can be assigned one Tone (or set to Off) together with volume level, pan value and effect on/off setting.

The D20 can store one such keyboard map (known as a Rhythm Setup) in its internal memory; fortunately you can store Setups to disk, RAM card (one per card) or via MIDI. As the ROM patterns use the default Setup, it's a good idea to store it to disk before making any changes.

An effect level setting for each note/Tone would have been helpful, but the really big disappointment in what is otherwise a powerful rhythm section is that you can't tune the Preset Rhythm Tones. However, the 64 Programmable Tones which can be used in a Rhythm Setup adopt the pitch of the note(s) they're assigned to. Among other things this allows you to reserve one octave for a bassline; the notes needn't bear any relation to the actual pitches, as you can transpose the Tone. To my mind this is a great feature, though, bearing in mind the limit of eight simultaneous notes in a pattern, not one to be over-used.

You record the 32 programmable rhythm patterns in familiar loop-in-overdub fashion. The D20 allows you to record from an external MIDI source, so for instance you could plug in an Octapad and bash away 'til your heart's content.

Quantisation can be selected at this stage (from 8th to 32nd notes including 8th and 16th triplets), but can't be altered subsequently. However, you can select different quantise values at any point during recording.

To erase notes you just select Erase in the LCD window and hold down the relevant notes on the keyboard as the pattern plays.

If you're in Performance mode you can play the last-selected synth sound over the rhythm patterns, but you can't change sounds (because the patch select buttons are assigned to pattern select). However, in Multi Timbral mode you an switch between up to eight sounds by setting the MIDI transmit channel of the D20 to the channel of the Part(s) you want to play. In fact you can set upper and lower transmit channels, with programmable splitpoint, so you can play two sounds over the rhythm patterns.


AS MENTIONED EARLIER, tracks 1-7 are dedicated synth tracks, each one allowing you to play a single Timbre at a time in Multi Timbral mode (with Performance mode set, all synth tracks play the same Patch). The dedicated rhythm track (track nine) consists of chained one-bar patterns, up to a total of 500 bars; these are the 32 preset and 32 programmable patterns discussed earlier. There are two methods of recording this track: real time (in which case you select patterns manually as the sequence records - the spontaneous approach) or step time.

Whereas the dedicated rhythm track requires you to chain one-bar patterns together, track eight allows you to record rhythm parts in extended linear fashion. This is an excellent idea, as it allows you to be spontaneous with rhythm parts which require it, while reserving the dedicated rhythm track for the more "orderly" pattern-based parts. Unfortunately, if you want to record into the sequencer from an external MIDI source you are forced to lose all other data already in the sequencer. This means that you can only use external recording on the first track that you want to record - so if, for instance, you've recorded rhythm patterns using the Octapad and chained them into the dedicated Rhythm track, you can't then go on and record an extended percussion workout into track eight using the Octapad. Why on earth does there have to be such a silly restriction?

The sequencer can record note, velocity, patch-change, pitch-bend, mod, hold, volume and pan data. Remember that aftertouch is non-existent on all Roland's L/A instruments apart from the D50/D550. Sequence data isn't memorised through power-down (apart from the dedicated rhythm track and its associated patterns), so you have to save it to disk or card before switching off.

The sequencer only allows real-time recording; steptime input and event editing are not part of the D20's vocabulary. There are two ways to initiate recording: a two-bar count-in or any MIDI note-on message. The initial track has to be recorded from bar one, but after that you can start recording other tracks from any bar within the length of the longest track (which determines the overall length of the sequence).

You can also re-record, punch in/out or overdub any section of an existing track (to bar resolution). Punching in and out an be accomplished with the Enter button or with two dedicated footswitches, and you can punch in and out as many times as you want during a track. However, you can't copy track sections within or across tracks, so if you want a one-bar bass riff repeated 48 times you'll have to play it 48 times.

Volume messages can be overdubbed using the data slider, while pan messages can be overdubbed by playing the 14 white keys centred around middle C. You can clear all or individual tracks, and independently erase patch-change and pan/volume data globally per track (1-8). Quantisation has the same range of values as for the rhythm patterns, but this time it's done after recording and applies globally to the selected tack. Not exactly ideal.

Sequence playback can be started from any bar, and you can mute any combination of tracks in real-time by pressing the eight Number buttons and A/B button (green pinpoint LEDs turn on/off to indicate track mute status). Sadly, these mute settings can't be recorded as part of a sequence.

The D20's sequencer has another silly shortcoming to its credit: if tracks are active locally they won't play over MIDI, but if you mute a track it automatically plays over MIDI. In other words, you can't layer internal and MIDI'd sounds. Perhaps even more frustrating, this means you can't combine and/or layer internal and external percussion sounds in a Rhythm Setup. Yet in Rhythm mode the D20 plays its patterns locally and via MIDI, allowing you to create any configuration of internal and external sounds that you want; go into Sequence mode and you've lost it. Now that is stupid.

Anyone wanting to sync the D20's sequencer to tape or to another MIDI instrument will be disappointed to learn that the D20 can neither send nor receive MIDI Song Position Pointer data. So even if you're slaving off SMPTE or intelligent FSK you'll have to start recording from the top every time.

There has yet to be an onboard sequencer which competes with the power of the computer-based option. Perhaps that's asking too much (though Akai looked to be game with the now-aborted MWS76 master keyboard, which would have had the company's sophisticated ASQ10 sequencer onboard). The D20's sequencer could hardly be described as sophisticated, though the features it does have are, on the whole, well thought out. You an certainly put together a complete song using it, which is what matters.


NO DOUBT THE D20 will provide many musicians with all they need in life. But you have to give the workstation option serious consideration. It all comes down to convenience versus flexibility. The D20 is not as flexible or as powerful as a modular MIDI setup based around an ST or a Mac - in fact, you could say as much of any workstation-styled instrument currently on the market. Yet the convenience of the D20's integrated approach is undoubtedly attractive. In many ways the D20 has been very thoughtfully designed, with plenty of subtle but effective touches. However, there are also a number of irritating aspects to the instrument - the most important of which should have come out in this review.

If the idea behind a music workstation is to allow the recording of a complete piece of music, you have to ask yourself what that means for you. Some of the greatest music ever composed was written for solo acoustic piano. On the other hand, you're unlikely to be able to record a piece for full orchestra on the D20. And even with 32 partials at your disposal the average pop/dance track could run into problems with sounds using three or four partials.

What's more, your definition of a complete(d) piece of music may take in effects and EQing on individual drums and individual synth sounds - which, as noted earlier, isn't really feasible on the D20. Then there are questions as to whether or not one instrument can produce all the sounds you want in your music, whether or not it has enough voices to play all the notes, and whether or not nine sequencer tacks are adequate. One point worth bearing in mind, though, is that if you eventually tire of the onboard sequencer you can always play the D20 multi-timbrally from an external sequencer.

The inclusion of an onboard disk drive is a big bonus (and definitely scores brownie points for Roland over Korg's M1), but it's a shame Roland haven't provided SysEx libarian facilities in conjunction with the sequencing memory.

There are many factors to take into account when considering an instrument like the D20. Sound-wise it's got a lot going for it, though it's by no means the self-contained instrument the workstation tag (which admittedly isn't Roland's, but which is nonetheless implied) would suggest. But the same could be said of all the instruments aspiring to workstation status. Will the workstation approach overtake the modular flexibility which MIDI has given us? Personally I an see computer-based production workstations running multiple MIDI progams (sequencers, scorewriters, editors...) in a true multi-tasking environment, perhaps with onboard digital audio editing and mastering, but I'm not so sure about combining the actual sonic components in one box - compromise seems inevitable.

All the same, the D20's particular flavour is well worth checking out.

Prices £1245: D10 £850; PG10 programmer £248. All prices include VAT.

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Music Technology - Copyright: Music Maker Publications (UK), Future Publishing.


Music Technology - Oct 1988

Gear in this article:

Synthesizer > Roland > D20

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Digital Synth

Review by Simon Trask

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