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E-Mu Emax Sampler

Polyphonic Sampling Keyboard

Article from Music Technology, January 1987

An exclusive, in-depth report on the machine that promises to bring Emulator quality to the masses. Paul Wiffen, Emulator fan, finds out if the promises are fulfilled.

First there were expensive Emulators, then there were more expensive Emulators, and now there is the cheaper Emax. Does it enhance E-mu's reputation?

THE RECENT HISTORY of America's musical instrument industry is littered with the memory of companies who have created a market exclusive to themselves, but have failed to keep pace with technological developments to make their products cheaper. This has left the competition - primarily Japanese - to make the biggest impact at the "affordable" end of things.

But all that changed with the news that Californian company E-mu Systems have a new sampling keyboard - the Emax - that weighs in at about the same price level as its Oriental competitors.

How have E-mu achieved this? Well, partly by taking advantage of the strong Japanese yen, but mostly by taking all the technology behind the Emulator II and condensing it onto one microchip - the E-chip.

This clever little device actually does much of its internal workings in 16-bit format, but in the Emax it takes the output of a 12-bit A-to-D converter (which does the sampling) and converts it to E-mu's proprietary data format for eight-bit storage, just like the EII does. So the Emax uses memory as efficiently as an eight-bit machine, but theoretically, without the quality loss you'd normally expect from such sample resolution.

And because eight-bit words only occupy two-thirds of the memory required by 12-bit words (each word represents an individual sample), the same amount of sample memory (512K) that several 12-bit machines have can be loaded in two-thirds of the time (around 26 seconds instead of 40), which is a real plus for live work. Partially full Emax disks load in even less time.

For someone familiar with the Emulator II, a quick look through Emax's spec gives a real sense of déjà vu. Over 17 seconds of sample memory at 27.7kHz sample rate, sequencing and arpeggiation, eight individual outputs, and so on. In fact, all that E-mu don't plan to give Emax is a SMPTE capability, and the expanded memory of the EII+ and the Hard Disk version.

But there are several areas where Emax goes beyond the capabilities of EII, and perhaps the most significant is the increased bandwidth it offers. Now, the EII's 27.7kHz sample rate is fine for most sounds; just look on factory disks from most other manufacturers and you'll find their samples are made at this sort of rate, as it's a good compromise between bandwidth and economic use of memory. But there are plenty of awkward sounds which can appear pretty ropey without the extra 3 or 4K bandwidth that a 42kHz rate gives you.

Emax offers six different sample rates from 10kHz (for a maximum sample length of 52 seconds for speech and the like) up to 42kHz for a bandwidth of at least 16kHz. And the highest rate still gives you the 12 seconds' sample time that the S900 and expanded Prophet 2000 give at the same rate, not the eight seconds that was on the prototype Emax.


EMAX'S SAMPLE MODULE (sounds like something for collecting rocks on lunar excursions) works in a similar way to the ElI's, with a VU-style display for signal level, sample length (and the new selectable rates), threshold or manually triggered sampling, and key assignment. But one thing I missed from the ElI was the ability to monitor the signal being sampled, and bearing in mind that Emax is more likely to be used away from studios (where independent monitoring is easily arranged), it seems strange E-mu should have omitted this.

Setting the correct signal and threshold levels is easy, though I soon found out that the Emax does not respond to an overloading signal the way the ElI does. So when the display says it's too loud, you'd better believe it.

Sample rate defaults to 28kHz, but if you decide you need a higher rate, the sample time you previously set remains the same (provided there is the memory left to do this), which is neat.

During tests, and at a sample rate of 42kHz, the sound quality was excellent - to the extent that an untrained ear could have trouble distinguishing between the original and sampled signals. Even more surprising was the fact that at 31 kHz (or even 28kHz), the results were still extremely good: a little crunchiness in tambourine and hi-hat sounds was the only immediately obvious change.

To my ears, this proves that any limitations noted in the fidelity of the EII when sampling more demanding signals (cymbals, snare drums, hi-hats, complete mixes of music, and so on) are due to its limited sample rate, and not E-mu's special data format.

"Sample rate defaults to 28kHz, but if you decide you need a higher rate, the sample time you previously set remains the same - neat."

Having obtained samples whose quality I was more than happy with, I headed for Emax's Digital Processing Module to chop them about. Truncating samples on the Emax is a cinch, thanks to the provision of both data sliders which move through the sample in large chunks, and Yes/No switches which step through each individual sample. Once you've set your start and end points, Emax politely asks if you want to make this permanent; if you do, it'll return the discarded memory to the pool available for your next sample.

Setting the loop points is done by a similar method, though here you determine the loop length by setting the loop start, rather than using a completely separate loop end. Now while this works OK, it's sometimes preferable to have complete independence between start and end points in a loop. But E-mu have implemented a release loop: this can be the same as the sustain loop, but if you want to set it different, you have the same parameters available as for the sustain loop.

Sadly, unless you're either very lucky or very skilful, manual looping will leave you with a whole bundle of clicks, glitches, and out-of-tune sections, not to mention unwanted tremolo and vibrato effects. But don't despair: E-mu have provided you with two powerful weapons in the war against unsightly loops: Autoloop and Crossfade Looping.

The first of these searches for points in the sample of equal energy and matches them together. This reduces the chance of clicks appearing in your loop, and is offered as an option whenever you finish setting start point and length on either loop.

But a more powerful technique for eliminating mess is Crossfade looping, as this actually alters non-matching waveforms after the start and before the end of the loop. It seems E-mu demonstrators, are so confident of the technique's universal applicability, they've taken to picking the worst loop points and setting Crossfade Loop to work - in front of numbers of people. Well, 1 certainly couldn't find a click or a glitch that it wouldn't smooth out, though seeing as the process of Crossfade Looping does alter the data in your sample (as the display rightly warns you), it's best to follow E-mu's advice and save your original sample to disk before experimenting.

The next section of Digital Processing is where the fun really begins, because it's here that you can Taper, Splice or Combine (ie. mix) samples.

Taper is great for smoothing out clicks at the front of samples and sharply cut-off reverb on drum sounds, for example, while Splice is more experimental, merging one sound into another (with definable crossfade time). Combine allows straight mixing of samples and is useful if the Dual Voice function we'll look at shortly is not enough for your layering demands.

But my favourite here was Gain Changing. You can use this to raise the level of quiet samples, but I preferred to boost perfectly respectable samples until they clipped and began to distort, just like they would if you put them through a fuzz pedal. Lots of filthy noises - s'wot rock 'n' roll's all about, innit?


AFTER YOU'VE PUT your multi-samples through digital processing, you'll probably want to go to Emax's Preset Definition section to place them across the keyboard. Much of the work will have already been done by the specifying of original pitch and low and high keys in the sample module, but more advanced configurations (like velocity or positional crossfading and layering), can be set up here by using Dual mode.

Now is probably as good a time as any to mention the fact that Emax has two oscillators per voice; in other words, it's able to play back two samples at the same time through one D-to-A converter. Each sample can have the following independent parameters: tuning, level and any of the digital processing which has already been done. But in Dual mode, the two samples share all the values in the Analogue Processing section (which we'll look at in a while). You can have different VCF, VCA, LFO and Pan settings if you wish, but you pay the price in the form of reduced polyphony. Emax becomes four-voice.

Dual mode allows you to double up samples and stay in eight-voice operation. Once you've switched the mode on and decided which of the two sets of parameters you're going to use, you can choose between XFade Off (this layers two sounds together); Velocity XFade (the strength of the keystrike determines the balance between the two sounds); Velocity XSwitch (where less than average force gives one sample, more the other); Positional XFade (which merges samples smoothly as you go up the keyboard); Realtime XFade (uses the mod wheel to fade between the two samples); or Realtime Xswitch (where a footswitch swaps the sounds). This has to be one of the most extensive lists of different keyboard assignments I've ever seen on a sampler- you should find one for just about any application you might encounter.

"Emax has one of the most extensive lists of keyboard assignments ever seen on a sampler... one for just about any application you might encounter."

Preset Definition also contains the Arpeggiator Setup, and while we're on the subject, there seems to be a running battle going on in Northern California to see who can produce the most versatile arpeggiator. Sequential started with the arpeggiator on the Prophet 2000 and then expanded on it in the VS, but I reckon features like Cruz Control (plays however many notes you hold down within the same note-value) and Interval (adds the specified interval to each note you are holding) put Emax just ahead. I'll admit to not liking arpeggiators that much, but if you do like them, you'll love this one.

The next section of Preset Definition - MIDI Setup - is more my bag. Each Preset can have its own individual MIDI parameters, so you can access them separately via MIDI (Mode 4). And this has some especially worthwhile implications for Emax's sequencer, as we'll see later.

And this is not the only versatile feature of Emax's MIDI implementation. MIDI Overflow mode, for instance, ensures that extra notes which Emax can't handle (ie. more than eight) are sent out via MIDI for a second Emax (maybe the rack version) to play. This allows for a 16-voice Emax system to be controlled from just one keyboard or sequencer.

You'll also find the more everyday aspects of MIDI implemented on Emax, like note velocity, program changes, assignable controller numbers (including pitch-bend and aftertouch), Local on/off, plus MIDI Clock and Song Pointers for the sequencer. My only criticism here is that Emu (like most American manufacturers) haven't presented this information in the condensed form of a MIDI Implementation Chart for quick reference. It mightn't always tell you the whole story, but it can make checking up on compatability a whole lot faster.

Emax's real-time controllers (left and right wheels, pressure, footpedal and two MIDI controllers) can be routed to nine different destinations, and footswitches 1 and 2 to another six. Without listing them all, I think it's safe to say that you can route your controls just about wherever you wish.

Preset Management is a module which allows you access to utilities functions which make sampling life a lot easier. These include Loading and Saving individual presets or the whole bank, Copying, Renaming, and Erasing presets. Unexciting, maybe, but Emax wouldn't be half as useful without them.

Analogue Processing

THIS SECTION INCLUDES a number of functions we know and love from the good ol' days of the Minimoog and Prophet 5, plus a few expansions. Both filter and amplifier envelopes, for example, feature an extra stage called Hold, which comes between Attack and Decay. This acts as a Sustain at full level, with programmable duration. In general, envelope control comes in useful with samples which have their own dynamics already recorded; you can leave these untouched in the early phases, and then bring in the Decay, Sustain and Release effects once you've reached your loops.

The filter has the usual cutoff, resonance, keyboard tracking and envelope amount parameters, and can be controlled by velocity, as can the envelope attack times, overall level, and (surprisingly) panning.

Emax is the first sampler to feature dynamic stereo panning. Besides being able to place each sample in the stereo picture (via a visual display), you can use different things to modify that picture (velocity, LFO, aftertouch, and soon).

The built-in Chorus feature is not a dedicated digital delay circuit as it so often is on synthesisers. Instead, it uses the four oscillators in each voice channel detuned against each other to create its effect. Unfortunately, the chorus amount is preset, and no signal-processing effect is going to be right for all types of sound. I'd like to have seen the chorus rate and depth adjustable for individual taste.

Next comes Keyboard mode, which offers two completely independent options: Solo and Nontranspose. Solo gives you monophonic, single-triggering keyboard response (a la Minimoog), which is good news for all you fundamentalists out there, though I reckon it would be nice to have multiple triggering as well. The Nontranspose mode gives you several keys to play a sample at the same pitch - good for playing fast snare rolls and other sounds which are only required to sound at their original sampled pitch.

"The best thing about Emax is not its factory disks, but that you can easily make disks every bit as good yourself, thanks to its fidelity, flexibility and userfriendliness."

The final section of Analogue Processing is an innocent-looking function labelled Control Enable. This allows you to disable any assign controller in any area of the keyboard, so you can get real independence between, say, a bassline in the left hand and a polyphonic keyboard part higher up the keyboard.


E-MU HAVE BEEN quite reticent about the capabilities of Emax's sequencer, but as far as I'm concerned, it has the one feature which is indispensible these days - the ability to record in sync on more than one MIDI channel at once. This means you can record your music on whichever sequencer has the features you need - autocorrect, step-time recording, punch in and out, visual editing, patterns and chains, multiple time signatures, whatever they may be. You 'then transfer the data to Emax's sequencer, save it to disk, and then you've got your sounds and your sequence all on one disk, in one machine, ready for live performance.

Does the system work in practice? Well, I recorded a complete piece on a Roland MC500, using each preset on a different MIDI channel, adding extra tracks on other synths and then bouncing the whole piece across into the Emax's onboard sequencer (putting the keyboard into MIDI Sync Record). And it worked just fine. All 16 MIDI channels were recorded on the 16 channels of Emax's sequencer, and in replay, played back both the internal presets and the external synths.

I then used a Fostex 4050 to check the MIDI Song Pointers, and successfully ran the sequence from various random bar numbers. So the Emax should be just as useful in the studio (saving tape tracks right to the mixdown stage) as it will be on-stage.

If you have no other sequencer, the one on Emax is fine if you only want to use it in real time, the way you would a multitrack tape recorder; it has multiple bounce-down and extension functions. And as already implied, its 16 channels can be used to sequence the internal presets (to a maximum of eight notes at any given point), or other MIDI instruments, It'll also transmit velocity, pressure and other performance data over MIDI. Synchronisation can be achieved by MIDI Clock, or 24, 48 or 96 pulses-per-quarter-note sync.

As I noted earlier, the Emax's stereo section has the ability to pan voices all the way across the stereo picture (not just hard left and hard right, like so many "stereo" keyboards). When used on its own, the Right socket also makes a mono mix available, and inserting a stereo jack in the right output (when the left is not connected) makes the stereo picture available when you're using headphones.

In addition to the stereo outs and the eight individual audio outputs, back panel connections are available for the various optional controls we have seen going through Emax's functions.

On the digital side, you'll find MIDI In and Out ports (with a software switch between Out and Thru) plus an RS422 standard interface. The latter will allow Emax to communicate with software packages (like Sound Designer for the Mac) at much greater speeds than are available with MIDI. Digidesign plan to have a compatible version of Sound Designer available simultaneously with Emax, so we can expect the same sort of working speed as with the EII.


THE EII IS known for its huge sound library, and E-mu are planning to allow Emax to take full advantage of this. They're obviously starting as they mean to go on, as Emax comes with ten disks as standard, most of which are familiar from the EII library.

The Grand Piano is excellent (with footswitch sustain) as are the Arco Strings, Big Brass and French Horn disks (which should please those who think sampling is all about piano, strings and brass). There's a very usable Hammond organ, a good male/female choir, and a tenor sax which can be made to work quite realistically so long as you play it sympathetically.

Drum sounds of varying quality are featured on several of the disks - and then there's the Rock Guitar. I found this disk unbearable on the ElI, and the source sound hasn't improved with its transfer to Emax. It's still terrible. The low-end powerchords aren't too bad, but the higher lead sound is thin and twangy. If I had a guitar that sounded like that, I think I'd use it for firewood. The acoustic guitar disk from the ElI library would have been a better bet.

Still, I suppose only one lemon in ten disks is no cause for complaint - and far too much attention is paid to factory disks in any case; they can turn great samplers into mere sample replay machines, and the people who use them end up sounding like everybody else.

Nope. The best thing about Emax is not its factory disks, but that you can easily make disks every bit as good yourself, thanks to its fidelity, flexibility and user-friendliness.

Although many people will end up buying Emax because of the disks available for it, I like Emax for its sampling and manipulation capabilities. I like it because it starts where the EII left off, with increased bandwidth, crossfade looping, dual voice capability, expanded MIDI features, panning and chorusing. I like it because it's easy to use and holds sequences, samples and presets all on one disk. But most of all, I like Emax because it sounds good.

Price £2599 including VAT

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The Perfect Repeat

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Simmons SDE Module

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

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Music Technology - Jan 1987

Gear in this article:

Sampler > Emu Systems > Emax

Gear Tags:

12-Bit Sampler

Review by Paul Wiffen

Previous article in this issue:

> The Perfect Repeat

Next article in this issue:

> Simmons SDE Module

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