Can a dedicated drum expander compete with the sonic flexibility of a sampler? The man from E-mu, he say yes.

During the '80s, the high price of E-mu Systems' samplers meant that they were largely owned by pro musicians, pro studios and BCCI account holders. The asking price of an Emulator may have been merely stratospheric compared to the out-of-this-world cost of a Fairlight or a Synclavier, but it was still high enough to bring most musicians down to earth with a bump once they'd finished flying high in their dreams - rather apt for a company named after a flightless bird.

But with the ushering in of a new decade, E-mu have at last started producing instruments for musicians who bank with the Midland. The 1U-high, 19" Proteus module set the tone in 1989 by making samples from the company's sizeable and well-regarded EIII sample library available in a playback-only format. The success of that module has encouraged E-mu to develop the sample playback concept into a line of instruments, first of all with last year's Proformance half-rack piano modules, now with the 1U-high, 19" Pro/cussion module, which as its name suggests, is a unit dedicated to matters percussive.

Describing Pro/cussion simply as a sample playback unit doesn't do justice to its capabilities, however. In an effort to compete with the sonic flexibility of the sampler, E-mu have given their dedicated expander a sizeable built-in library of drum and percussion samples, but there's a lot more to Pro/cussion than lots of sounds dropped into a box with a MIDI socket fitted to it. One advantage a dedicated unit has over a general-purpose sampler is that it can be optimised for a particular musical role, and, to judge from the way Pro/cussion has turned out, I'd say that this fact was the starting point for its designers. As a result, Pro/cussion is an instrument with plenty of bells and whistles - and I'm not talking about its samples. Included are features designed to make it as sonically flexible as possible, and plenty designed to make it as musically responsive as possible. So have E-mu come up with the ultimate instrument for the rhythm programmer?

BEGINNINGS

THE LEVEL OF organisation that you encounter first on Pro/cussion is the Kit. This is basically a collection of up to 24 sounds which are mapped across the MIDI note range in a multisplit texture. Pro/cussion contains 128 Kits, 64 of which are user-programmable.

If you set Pro/cussion to Omni receive mode, the currently-selected Kit in the main (Play mode) LCD page can be played via any MIDI channel. Poly mode is available if you want Pro/cussion to receive on one MIDI channel (1-16); in this case, both the MIDI receive channel and the Kit are set on the main page.

Alternatively, with multitimbral MIDI reception selected you can trigger up to 16 of Pro/cussion's Kits at once, one on each MIDI channel. Any channels which you don't want Pro/cussion to respond on can be set to "Off". Voice Assignment mode offers you an unusual degree of control over how the expander's 32 voices are assigned across the MIDI channels and within individual Kits; however, to begin with it's probably best if you stick to Poly (32) - simple dynamic allocation of all 32 voices across the active MIDI channels.

Kits can be selected via MIDI independently for each channel using patch change commands, allowing you to automate kit changes within your MIDI sequencer. For added flexibility, Pro/cussion allows you to create a patch-to-kit map, so that you can link any MIDI patch change to any Kit.

By allowing you to trigger sounds from more than one Kit at the same time, multitimbral reception can lessen the need for you to create your own custom combinations of sounds within a Kit. For instance, instead of bringing hip hop kick and snare drums and hi-hats together with congas and some sound effects in your own kit, you could assign Pro/cussion's Hip Hop, Latin Drums and Sound FX Kits to three different MIDI channels.

Creating your own Kits on Pro/cussion is a matter of defining MIDI note ranges for up to 24 Zones and assigning a Stack to each Zone. Setting up the Zones can be a bit tedious, although you're helped by being able to play in the lower and upper notes for each Zone from a MIDI controller. Not that you have to start from scratch every time. For one thing, you can edit existing Kits if all you want to do is make a few changes. For another, you can start from a blank "template", where the Zone mapping has already been done and all you have to do is select the Stacks. A third option is provided by two User Zone Maps: if you've decided on a standard Zone mapping of your own, program it into a User Zone Map and then set a MIDI channel to User 1 or User 2 instead of Kit in Master Mode; your Zone mapping will then override that of each Kit which you call up on that channel.

You could use the User Zone Maps as a convenient means of mapping Pro/cussion's samples onto rhythm sequences previously recorded using another machine - if Zone one always has a kick drum sample assigned to it, map Zone one to the note in your existing sequences which was used to trigger a kick drum. This is presumably the line E-mu were thinking along, because they've provided several preprogrammed Zone Maps which match selected factory-programmed kits on some well-known drum machines and percussion controllers (Alesis, Roland R5 and R8, the Roland Octapad series and E-mu's own SP12).

By now you're probably wondering what a Stack is. Well, here we start to get into the deeper side of Pro/cussion. A Stack is essentially a layer or velocity-split configuration of up to four Instrument Layers, and an Instrument Layer consists of an Instrument (one of Pro/cussion's samples or waveforms) routed first through a DCA with an optional Volume Envelope modulator, then through a pan module to Pro/cussion's audio outputs. Within each Instrument there are 11 modulation destinations, each of which can be modulated by any one of ten sources. Also, each Stack has its own LFO which can be used to modulate the pitch and/or the volume of one or all of the four Instrument Layers, while the rate and amount parameters of the LFO can themselves be modulated by one of the ten mod sources.

"There's a lot more to Pro/cussion than lots of sounds dropped into a box with a MIDI socket fitted to the back of it."

"But all I want to do is trigger some drum samples", you protest. Well, E-mu have included a massive 548 factory-preset Stacks in ROM, so it's quite possible that you'll find more than enough sounds to keep you happy without ever needing to create your own Stacks. There again, if your attitude is that you only want to use sounds that are unique to you, delving into Stack creation will prove to be rewarding, because, as I pointed out earlier, there's a lot more to Pro/cussion than sample playback - Stack parameters provide plenty of scope for creating new sounds.

You can always break yourself into Stack programming gently by tweaking parameters on an existing Stack. The way the programmable Stack locations work is that each user Kit has eight Stack memories which you can program yourself. You can then assign them to Zones alongside preset Stacks (obviously, no Kit of more than eight Zones can consist solely of your own Stacks).

OPERATION

GETTING TO GRIPS with the detail and depth of Pro/cussion may take a bit of effort, but finding your way around the expander's software pages and editing its parameters is easy to pick up. This is partly because Pro/cussion keeps things simple by effectively putting every parameter on the same operational level rather than forcing you to delve into multiple hierarchical levels and remember which branch takes you where. It's also because the expander minimises the number of physical operations required to program it. There are just two mode buttons, Master and Edit; pressing either one of them takes you into the relevant mode, while pressing the same button again takes you back to the Play level, which consists of just one LCD page. This displays a MIDI channel number, the number and name of the Kit assigned to the channel, and master volume level and pan position settings for the channel. Pan position can be "K" (individual Instrument Layer settings apply) or a value in the range ±7 (all Instrument Layers are forced to the indicated position).

Successive presses of the Cursor button cycle the cursor around the LCD page's parameters; alternatively, if you hold down the Cursor button, you can use the stepped, infinite-rotary Data knob to move the cursor in either direction. Turning the Data knob on its own edits the value in the selected parameter field. In Master and Edit modes, turning the Data knob when the cursor is on the parameter name steps you through the LCD pages; turning it while the cursor is on a value field edits the value.

It's all straightforward enough, and I found that with a little familiarisation I was charging around the LCD pages and getting to where I wanted to be very quickly. Having said that, operation is a little fiddly; I would have preferred to see the Data knob dedicated to editing parameter values and an extra knob dedicated to stepping you through the LCD pages.

ROUND THE BACK

THERE'S NOT TOO much to see on the unit's rear panel. MIDI In, Out and Thru sockets provide one kind of link with the outside world, three pairs of stereo audio outs provide another. Additionally there's the power input socket; apparently, Pro/cussion automatically switches itself for 110 or 220 volt operation.

The MIDI Out socket, in case you're wondering, is included to allow SysEx dumping of Pro/cussion's data. You can send out Master settings, the MIDI patch-to-Kit map, User Zone Maps, Factory Kits, User Kits and One Kit. SysEx is also used to enable remote editing of individual parameters within the currently-selected Kit.

The three stereo pairs are labelled Main, Sub 1 and Sub 2, with the main pair having the usual mono/stereo option. There's no separate headphones socket, but the Left socket of the main pair can be used as a stereo headphones output.

As on Proteus, the Sub pairs can optionally be used as effects sends and returns. Using stereo jacks, the tip serves as the send and the ring as the return, with the returns on the Left sockets going to the left buss and the returns on the Right sockets going to the right buss; these signals are then summed with the Pro/cussion output at the Main stereo outs.

"If rhythm is an important feature of your music, you should check out Pro/cussion - we're talking powerhouse stuff."

Pro/cussion sounds are routed to outputs via a Submix Group section. This contains 16 Submix Groups, each one named after an instrument type (kick, snare and so on). Each Zone within a Kit can be assigned to one of these Groups, while each Group can in turn be globally assigned to one of eight output options: Main, Sub1, Sub1L, Sub1R, Sub2, Sub2L, Sub2R, or Layer; if the latter is selected for a Group, each Instrument Layer in the Stack(s) being routed via that Group will be assigned to a separate output jack.

The idea is that if you route all snare drums, say, to the snare Group, they'll automatically appear at the same output. Because you can change the output routing at any time, you could route whatever snare you're using out of the Main pair while putting a rhythm together, then reroute it to a separate out for recording purposes. Also, any of the Groups can be turned off at any time, giving you an easy way of removing instruments from a stereo mix.

INSTRUMENTS

AT THE HEART of Pro/cussion, of course, are the source sounds which form the raw material for its Instruments, Stacks, Zones and Kits. Pro/cussion has 140 sampled sounds and 80 single-cycle waveforms stored in 4Mb of ROM (with room, apparently, for another 4Mb to be added at a later date, as on Proteus), and uses 16-bit-linear data encoding and a 39kHz playback rate. The sampled sounds consist of 12 bass drums and 26 snares, six toms, ten hi-hats (open, closed and various stages in between), several crash and ride cymbals, a selection of more off-the-wall percussive samples ('Big Hammer', 'Metal Stack', 'Lazer Hit', 'Rap Scratch', 'Pipe' and 'Clank') and a good number and variety of Latin percussion samples, including cabasa, guiro, shekere, timbale, tumba, quinto and hembra. E-mu have included the sounds produced by these percussion instruments when they're struck in different ways - quinto slap open, slap closed, tip and heel - allowing you to create more authentic-sounding percussion parts if you're so inclined.

While these samples take you towards authenticity, the four samples labelled 'Kick Space', 'DarkK-Space', 'Snare Space' and 'DarkSnSpace' take you into a more unusual realm. Basically, E-mu have used the Transform Multiplication function on their Emax II sampler to create four reverb "tail" samples which can be manipulated in the same way as the instrument samples, which includes being able to shape the reverb decay using an amplitude envelope. You can then layer one of these samples with various instrument samples to give the impression of reverb on selected instruments. You can also do weirder things like reverse the reverb, modulate it with a pitch envelope and tune it up or down. Finally on the sample front, E-mu have included a few punchy synthbass samples. A number of the Kits have a bass sound assigned to a couple of octaves above the drum and percussion sounds, making it very easy to quickly try out a bassline while you're working on a rhythm track.

The waveforms are divided into three categories: synth classics (sine, triangle, square and sawtooth), 22 harmonic waveforms (variously providing odd and/or even harmonics within different octaves) and 54 digital waveforms (lots of offbeat metallic sounds). A very effective way of customising the drum and percussion samples is to mix in some of these waveforms - which of course is what the Stacks are all about.

STACKS

PRO/CUSSION'S FACTORY STACKS give you a massive library of sounds to draw on, and show off very effectively just how much you can "expand on" the source samples. For instance, there are some 60-70 kick-drum Stacks and around 100 snare-drum Stacks, providing a far wider variety of kick- and snare-type sounds than you get from the samples alone. Fortunately you can copy factory Stacks into RAM custom Stack locations, as taking these Stacks apart is an ideal way to learn how to program your own. In this connection, a Stack function called Audition Layer very helpfully allows you to isolate individual Instrument Layers by "soloing" them.

It's now time to take the plunge and look at Stack parameters in more detail. There are five parameters associated with each Instrument within an Instrument Layer: Reverse, Delay, Pitch, Tone (basic filtering) and Sample Start. If you enable Reverse, the Instrument is played backwards. Delay time determines how soon the Instrument will start playing after the Stack has been triggered; this can be set on a scale of 0-63, which covers a time span of 0-13 seconds! One obvious use for Delay is to create echo effects by assigning progressively bigger time delays across the four Instrument Layers. There are plenty of tricks you can get up to here, such as having a different sound, and/or changing the pitch of the sound, on each "repeat". As Pro/cussion allows you to assign two Zones to the same MIDI note range and so layer up to two Stacks, you can create echo effects with up to seven "repeats".

As its name suggests, the Sample Start parameter allows you to define a playback start point other than the beginning of the sample. Using a combination of the Sample Start and Delay time parameters and layering two or more Instruments, you can combine the attack of one Instrument with the decay of another. What's more, Sample Start is a modulatable parameter, so for instance you could control the attack characteristics of a Stack from velocity.

Other modulatable parameters within an Instrument Layer (or across all four Layers) are Instrument pitch and tone, DCA accent and level, and pan position. As mentioned earlier, you can modulate the DCA using a volume envelope. This envelope's three stages - Attack, Hold and Decay - can themselves be modulated. Modulation sources are: velocity, MIDI note number, Trigger Tempo, Random, MIDI Control A/B/C/D (any four MIDI continuous controllers), aftertouch, pitchbend wheel and LFO. Within a Stack, up to four modulation patches can be programmed, a patch consisting of a mod source, a mod destination and a mod amount (which can be + or -). The destination parameter in each case can be in all four Layers or an individual Layer.

"You can do some strange things here - rapid repeats which change in pitch, or trigger from a different point in the sample."

The simplest Stack configuration is layering, but Pro/cussion also provides various options for dynamically-controlled switching or crossfading between different Instrument Layers within a Stack (in response to velocity or a MIDI controller, say).

One of the most striking features of Pro/cussion is Trigger Tempo. You may have noticed that this is one of the mod sources listed earlier. Basically, you can program a tempo of between 20-260bpm, and when you play two or more notes within the time defined by the tempo (so 0.5 seconds at 120bpm) Pro/cussion generates a control signal which is routed to whatever mod destination Trigger Tempo is assigned to. You can do some strange things here, like have a rapid repeat which changes in pitch, brightens or darkens in tone, or triggers from a completely different point in the sample - and you can make the change as subtle or as extreme as you want.

VERDICT

IF RHYTHM IS an important feature of your music and you like your drum and percussion sounds adventurous, contemporary, beefy and punchy, with plenty of oomph where it's needed and bags of attitude, Pro/cussion should definitely be on your list of Things I Should Check Out. We're talking powerhouse stuff, here.

There's a great deal of depth and a great deal of attention to detail in Pro/cussion. The sonic versatility provided by its samples and waveforms coupled with its layering abilities, the plentiful editing options provided by the synth-style architecture of its Instrument Layers and the tremendous sonic flexibility of its dynamic modulation features ensure that there's ample scope for the creative sound programmer.

At the same time, these very features have allowed E-mu to provide you with a large and versatile factory-programmed sound library, so you can work at the straightforward Kit level without needing to get your hands dirty at the deeper programming level, if programming isn't really your thing.

Shortcomings? Well, I would have liked to have had more than 24 Stacks per Kit; admittedly, because you can use Pro/cussion in a MIDI multitimbral fashion, you can easily trigger different Kits simultaneously, but personally I would still have liked more sounds within a Kit. I would also have liked more than eight custom Stacks per Kit - once you start getting into programming in a big way, and uncover the real versatility of Pro/cussion, eight can seem a bit limiting.

Talking of sound programming, filtering on Pro/cussion is basic to say the least. The filter cutoff point can only be set by a dynamic modulation source, which makes it hard to fine-tune the timbre of a sample or waveform, you only get low-pass filtering and there's no resonance. Also, the filter didn't allow me to roll off as much top end from some of the bass drums as I wanted to.

What about Pro/cussion's lack of a ROM card slot or two for plugging in further samples? Well, I reckon the expander's ability to "transcend" the sonic range of its built-in samples so effectively makes this much less of a problem than it might be on a unit which allows you to do relatively little to its samples. Having said that, the prospect of an extra 4Mb of sample ROM is not one to be sniffed at.

Ultimately, Pro/cussion can't replace the particular sonic open-endedness of a sampler, but I'd say it has quite enough going for it to make it an essential instrument wherever contemporary rhythm tracks are being programmed.

Now you too can be a Pro.

Thanks to The Synthesiser Company for providing the review model.

Price £749 including VAT

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