Multitimbral Synth Expander
The latest box out of the Roland stable to incorporate the D50's L/A synthesis. Simon Trask examines how a multitimbral expander designed with the home organ market in mind will find its way into pro studios.
Home organ add-on or hi-tech outboard voicing unit? Roland attempt to bridge the gap with a multitimbral instrument that combines the linear arithmetic synthesis of the D50 with operations simplicity.
THERE'S NO DOUBT now that hi-tech recording is moving steadily towards the tapeless studio. Consequently, traditional multitracking techniques are being replaced by concurrently-sequenced tracks - which in turn places greater demands on the sonic capabilities of the instrument(s) being sequenced. Obviously, an instrument that can only play a single sound at a time (monotimbral), can be rather limiting where sequencing is involved. Cue the multitimbral instrument.
While sampling instruments are multitimbral more or less by default, synthesiser design has been slower to respond to the demands of these modem recording practices. Fortunately manufacturers are now making multitimbrality - the ability to play multiple sounds (timbres) at the same time - a priority. Ensoniq's ESQ1, Korg's DS8, Yamaha's FB01, TX81Z and TX802, and Kawai's K5 and K5M all offer sophisticated multitimbral implementations.
Roland themselves have already experimented with multitimbrality on their MKS7 Super Quartet expander. This allowed simultaneous generation of three synth parts and a rhythm part. The company's latest multitimbral offering is the MT32 expander, which provides the by-now renowned L/A synthesis of the D50 synth in eight polyphonic Parts together with a Rhythm Part which uses 30 PCM drum and percussion samples (electronic snare drum and half-open hi-hat have been added to the original 28). These are apparently almost the same set of sounds that are to be found on Roland's newest drum machine, the TR626, and as you might expect, maintain the standard of the company's digital drum machines. Both the synth and rhythm sounds respond to attack velocity via MIDI.
The MT32 retains the same sound parameters as the D50, but drops the synth's chorus and EQ sections and Chase Play mode. Onboard reverb is still the order of the day, however, albeit with four rather than 32 reverb types - and no, you can't apply different reverb settings to different Parts.
The MT32's sounds can be edited from the D50 or its associated PG1000 programmer, but the results can't be stored to the expander; nor can sounds be transferred directly between the two instruments.
THE MT32 WAS developed by Roland's Contemporary Keyboards division in Europe. In other words, its origins lie in the home keyboard market. Yet clearly the instrument will find its way into a lot of home and pro studios, as well as being an attractive proposition for MIDI guitarists - so we have the unusual situation of a hi-tech musical instrument being marketed by both the Contemporary Keyboard and Pro divisions of Roland UK.
What will no doubt frustrate potential studio-based users of the MT32 is the lack of any individual outputs for the drum sounds, or even of separate outputs for the Rhythm Part and the synth Parts. Instead, everything goes out of a single pair of stereo outputs. The MT32's background explains why individual outputs weren't exactly high on Roland's list of priorities. Many home keyboards (Roland's included) have an auxiliary audio input which allows a second instrument to be played through them as an alternative to an external keyboard amplifier and/or mixing desk. And in case you're wondering why Roland should have developed a multitimbral instrument for the Home market, bear in mind that home organs typically have two manuals and a pedalboard, each of which are capable of playing different sounds and of transmitting on different MIDI channels. Add the fact that manuals on some organs can be split, and that any rhythm and chordal auto-accompaniment sections can often transmit over MIDI, and you're using quite a few MIDI channels. In other words, multitimbrality is nothing new to "lounge" musicians, but in the context of performance rather than recording.
In attempting to straddle the two markets, Roland have come up with an instrument which functions on two levels: on one level it's a preset instrument with a friendly front panel, whilst on another it's a programmable instrument with greater operational flexibility if you hook it up to a suitable computer-based editing program. Roland themselves will in all likelihood be producing software to run on the IBM PC/Amstrad PCW, while other companies in the UK (such as Soundbits) will be catering for Atari ST users. Software writers will find full System Exclusive details in the back of the MT32's manual.
THE MT32 COMES with 128 preset Timbres onboard, which are divided into 17 Sound Groups: Piano, Organ, Keyboard, Synth Brass, Synth Bass, Synth 1, Synth 2, Strings, Guitar, Bass, Wind 1, Wind 2, Brass, Mallet, Special, Percussion, and Effects. The number of sounds in each group varies from four to eleven.
The sounds are of the same quality as those to be found on the D50, though perhaps more variable - and some could do with a spot of the D50's chorusing to fill them out.
Brass and Synth-brass groups both offer powerful sounds, with piercing trumpets and horns from the former benefiting from the realism of the PCM attack samples, while the Synth-brass sounds have the typical gruffness of Roland synth circuitry.
The MT32 doesn't feature as full or as varied a complement of string sounds as the D50, but nonetheless, maintains the standard set by that instrument - and the ethereal (and Traskian favourite) "Soundtrack" preset puts in yet another appearance. Fretless and acoustic bass sounds are effective, but a better range of sounds in the basement wouldn't have gone amiss.
Among the best sounds are tuned percussion, plucked string instruments and woodwinds of both Western and Eastern persuasions. There are also some very impressive percussion sounds, including the deeply resonant "Taiko" - a rather large Japanese drum, I presume - while Roland haven't neglected to provide a good range of shimmering, atmospheric sounds such as Fantasy, Atmosphere (of course) and Echo Bell. The obligatory Effects include orchestral hit, telephone, bird tweet and one-note jam (hold a note down and you've got a rather messy rhythm section courtesy of looping PCM partials).
Unfortunately, the acoustic and electric pianos let the side down, being for the most part too thin to sound particularly convincing. On a more positive note however, the electric and pipe organ sounds are better conceived, and there's a very lively and well-detailed harpsichord sound.
NO DOUBT YOU'VE figured out by now what the MT of the MT32's name stands for. The 32, however, refers to the fact that 32 partials can be played simultaneously. "Partials?" you say. Well, in case you missed the D50 review (MT, May and June '87), I'll recap. A "partial" is a complete sound which can be either a synthesised sound or a PCM-sampled attack waveform (primarily but not exclusively from acoustic instruments such as pianos, strings, trumpets, horns and tuned percussion). These can be played individually or combined in groups of from 2-4 partials.
Each of the eight synth Parts on the MT32 can be assigned a separate "Timbre" of from 1-4 partials. This is actually an improvement on the D50, in that the MT32 is 32-note polyphonic if you're only using single-partial sounds (whereas the D50 is limited to 16-note polyphony regardless of whether you're using one or two partials for each sound).
Let's look in more detail at the MT32's organisation. Imagine that you've assigned to Part One a two-partial bass sound made up of a sampled double-bass bowed attack and a synthesised bass sustain/release. On Part Two is a four-partial string section, while on Part Three is a two-partial French horn. The bass and horn lines are monophonic, while the string part consists of sustained five-note chords. That's 24 partials. With, say, a two-partial electric piano sound you could play a further four notes at a time; if the electric piano sound used four partials, this would be reduced to a maximum of two. However, as partials are allocated dynamically among the Parts, if your string part reduced to three-note chords or even dropped out altogether at some point, you'd have more partials available for the other parts.
But the sounds of the MT32's Rhythm Part also enter into this equation. Each percussion sound is a single partial, so if you're running the Rhythm Part from a sequencer you'll need to bear in mind that as you make your rhythm track more dense, fewer partials will be available for the synth Parts. Alternatively, it's possible to use a maximum of 32 percussion sounds at the same time.
Another of the MT32's features is called Partial Reserve. This allows you to allocate a fixed number of partials to each Part (within the total of 32), so that, for example, you can always be confident of being able to play five-note string chords.
Partial Reserve is one of the many features that are, to all intents and purposes, hidden from you unless you have suitable software - as mentioned earlier. But for the moment, let's concentrate on what you can do from the MT32's front panel. There are six Part buttons (five synth plus Rhythm), four buttons labelled Sound Group, Sound, Volume and Master Volume, and a Select/Volume knob. You can select Parts 6-8 by pressing the Master Volume button and Part 1-3 buttons respectively.
Pressing the Master Volume and Volume buttons allows you to change the reverb mode on a scale of 0-10 using the Select/Volume knob. This actually seems to change the reverb time setting, zero being no reverb. As it's a global parameter, a zero setting is a quick way of taking the reverb off all sounds if you want to substitute external processing - which is one up on the D50. Default reverb is Hall, which tends to be quite noisy on longer settings - particularly at the tail end of the reverb signal.
Master Volume plus Sound Group allows you to alter the MT32's master tuning (from A=427.5Hz to A=452.6Hz), while Master Volume plus Sound allows you to set a Unit number from 1-32. If you're using more than one MT32, giving each one a different unit number will allow them to be addressed individually for editing purposes.
Master Volume plus Part Four allows you to set MIDI Overflow mode, which passes on any received notes via MIDI Out when all 32 partials are in use. Master Volume plus Part Six allows you to alter the default channel settings of the synth Parts from 2-9 to 1-8, while Master Volume plus Part R (Rhythm) is a quick way of resetting the MT32.
Despite the combined button-pushes, front-panel operation is simplicity itself because Roland have presented you with limited options.
Good news is that Roland have given the MT32 plenty of performance flexibility through making pitch-bend and MIDI controllers (in this case modulation, volume, panpot, expression and hold) independent for each synth Part. So now you can use the sustain pedal for those electric piano chordal washes on one Part and the pitch-bend wheel for that wailing lead synth solo on another Part. And of course, individual pitch-bend control makes the MT32 suitable for MIDI guitarists.
Roland have also implemented the new Reset All Controllers message (controller code 121), which could prove extremely useful. But not everything in the MT32's MIDI garden is coming up roses: keyboard players who like to make lavish use of aftertouch will be disappointed to learn that this is one MIDI command the MT32 won't respond to.
IN ADDITION TO the 128 preset timbres the MT32 has 64 user-programmable timbre memories. However, these user memories aren't battery backed-up, so they are lost when the MT32 is switched off. To get any new sounds onboard in the first place you'll need to hook up appropriate editor/librarian software (or a sequencer with SysEx dump facilities) and load in the sounds each time you power up. Not such a problem in the modem computer-centred studio environment, where it's becoming increasingly common to do this sort of thing anyway.
The MT32's internal organisation consists of 128 Patches, each of which calls up a single timbre from either the preset or the user memory, and additionally allows you to define a transposition value (+/-24 semitones), fine-tune value (+/-50 cents), bender range (0-24 semitones), assign mode (more on this later) and reverb on/off for that timbre. Default Patch:timbre assignment is Patch one:preset timbre one through Patch 128:preset timbre 128. To edit Patch settings and alter the Patch:timbre assignments (so that, for instance, Patch one calls up a user rather than a preset timbre) you'll need recourse to external software.
Roland have also built more sophistication into the MT32's Rhythm Part than front-panel operation would lead you to believe. Not only an the default MIDI note assignments and pan values be altered for the 30 PCM drum and percussion samples, but each MIDI note (24-87) can also be given its own output level and reverb on/off setting. The last is particularly valuable, as you can be selective about which percussion sounds you want the MT32's reverb to take effect on.
Even more interesting is that any of the user timbres can be incorporated into the Rhythm Part's MIDI note assignment "map", in which case the note assignment defines the timbre's pitch. Remembering that up to 32 partials can be allocated to the Rhythm Part you could build up a sophisticated rhythm track - albeit at the expense of the other Parts.
The expander's built-in reverb also takes on new flexibility with external intervention, as via System Exclusive commands you can select any one of four reverb types (room, hall, plate, and tap delay) together with reverb time and level.
As mentioned earlier, the MT32 has been given default MIDI channel assignments for each Part. The eight synth Parts can be on either channels 2-9 or 1-8, while the Rhythm Part remains on channel 10. However, these assignments can be changed from editing software using System Exclusive commands. Each Part can be allocated to any one of MIDI channels 1-16. Not only does this allow you to reassign Parts to suit your own system, but you can assign more than one Part to the same MIDI channel to create layered timbres consisting of more than four partials. By making use of the fine tune Patch parameter, you could also layer the same sound and detune it.
Finally, there's the aforementioned Assign mode, which can be programmed for each Patch. There are four options which determine whether priority should be given to first or last notes, and whether repeated notes should be reassigned to the same voice or use a new voice. The latter feature is more good news for MIDI guitarists, as it means repeated notes on a single string (and therefore the same MIDI channel) can be reassigned to the same voice. In fact, this feature was suggested by Roland's guitar division.
Because the MT32 relies to such an extent on external software to reveal its true flexibility, that very flexibility is ultimately at the mercy of the software which becomes available. We can but wait and see.
ROLAND MUST BE onto a winner with the MT32. Multitimbral L/A synthesis for under £500 is going to be too much for anyone enamoured of Roland's synthesis system to resist, despite potential complaints about lack of individual outs and the need to invest in a computer and editing software to get the most out of the instrument. Clearly such software will appear before long, and with many home and pro studio owners already possessing a computer the cost of editing software by itself shouldn't be prohibitive.
The preset sounds that Roland have provided are up to the standard of those to be found on the D50, while the range of sounds is broad enough to keep most people happy for some while ('til the sound libraries start to appear on disk, anyway).
The MT32 should sit happily in any modern studio, where its multitimbral power will be a welcome asset. There again, start considering the multitimbral power that three MT32s (at around the same price as a D50) would give you. Now you're talking.
Price £450 including VAT
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Review by Simon Trask
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