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Akai S700

12-bit Sampler (Retro) By Paul Sellars
Published March 2001

Akai S700

Most of us know of the legendary S900, which set a pattern that would be followed by succeeding generations of Akai samplers, but who remembers its contemporary, the less well‑endowed S700? Paul Sellars renews the acquaintance.

Back in 1987, affordable sampling was still a pretty new phenomenon. Sample times were, by today's standards, laughably limited, and built‑in RAM came in almost 'pocket calculator' amounts compared to today's monster 200Mb‑plus sampler RAM capacities.

Akai's 12‑bit S700, launched in the late summer of that year as a spin‑off from the X7000 keyboard sampler, was part of the company's follow‑up to their own ground‑breaking debut, the S612 rackmount sampler, and a smaller sibling to the very influential S900, which was making its name at around the same time. The S700 marked the beginning of a long and venerable tradition of beige boxes (the S612 was black) with S‑prefixed names, which brought the world the legendary S1000, and which is continued to this day by the fearsomely powerful S5000 and S6000 super samplers.

The S700 illustrates well the standards of the day. While the features of this early sampler may seem feeble and limited, compared to the hard disk‑recording, cinematic display‑toting monsters of today, seen in its proper historical context, at the time it was actually a respectably powerful machine, offering near professional‑quality sampling at a comparatively reasonable price. Even today, it has qualities that make it a characterful part of a studio.

Beige Beauty

Akai S700

The S700 occupies a familiar 2U, 19‑inch rackmount box, weighs in at a reasonably hefty seven kilograms, and boasts the kind of bomb‑proof, no‑nonsense design that will be familiar to users of all Akai's S‑series samplers. Nineteen buttons, a large data wheel and a 16‑character backlit LCD make up a simple, straightforward user interface, offering easy access to all of the S700's functions.

Three knobs control recording and monitoring levels and master volume, and there are dedicated mic‑ and line‑level inputs on quarter‑inch jacks. There's also a 'Rec/PB Trigger' socket, which enables you to trigger the recording or playback of samples by hitting a footswitch (originally available from Akai as an optional extra) or with an appropriate audio signal — a firm tap on a microphone seems to work. Finally, there's a line‑out socket, which is duplicated on the back panel.

Also on the back panel are the standard MIDI In, Out and Thru ports, a contrast knob for the LCD display and a 'Program Up' jack, which allows you to advance through programs incrementally by pressing another optional footswitch. More interestingly, there's a 13‑pin DIN socket, which can be used to output the S700's six voices independently. The original purpose of this was to feed audio via an optional cable to one of Akai's older synthesizers (the AX60, AX73 or VX90), so that samples from the S700 could be processed with the synth's filters and envelope generators.

If you don't happen to own one of the above‑mentioned synths, this DIN output might still potentially be of some use. The S700 manual includes a wiring diagram of the relevant pins, and it probably wouldn't take too much skill with a soldering iron to knock up some kind of custom cable to channel the six signals to independent phono or jack plugs — although I must stress that I haven't tried this, I have no intention of trying this, and I am not available to offer advice or technical support to anybody who decides to try this!

Six Appeal

Switch on the S700 and it quickly boots its operating system from ROM. By default, the first thing you see is the 'Load SX' page, from which you can load sample data from the built‑in QuickDisk drive (see 'A Quick Warning' box for more details). A QuickDisk drive was also built into the S700's predecessor, the S612, and the S700 can load samples from S612‑formatted disks as well as its own — should the need ever arise!

A total of six sampled voices in memory any one time is available from the S700, though this is increased to 16 if the optional ASK70 expansion board is installed. An S700 sample consists of not only the all‑important audio data, but also information about pitch, loop points and even LFO settings (the S700 has a fixed‑waveform LFO, which can be used to modulate pitch, creating simple vibrato effects). An S700 Program controls the keyboard range to which a particular sample will be assigned, and allows you to assign different samples to different keyboard ranges, all under the same Program number. In this way, a single Program can be created to map six different samples — from, for example, a drum kit — across a MIDI keyboard.

A peculiarity of the S700's architecture means that not only can a maximum of six samples be held in RAM simultaneously, but also that only one sixth of the total available sample RAM can be assigned to any one of those samples. To put this in context, at the S700's top 'bandwidth' of 16kHz, each of its six samples is limited to a length of 0.8 seconds. You cannot, however, opt to devote all available sample RAM to recording one sample 4.8 seconds long (6 x 0.8 seconds). In short, the memory is not dynamically allocated and the amount used for one sample has no bearing on the amount remaining for the others.

This is somewhat frustrating, since it effectively limits the sampler to recording short percussion samples only, unless you are willing to reduce bandwidth quite considerably, or go to some lengths looping instrument samples. At a bandwidth of 1.6kHz (the S700's lowest setting) the maximum length of each sample is increased to a more respectable eight seconds, but at this bandwidth the S700 produces distinctly lo‑fi results that won't be pleasing to everyone's ears! Strangely enough, the ASK70 expansion board actually does nothing to address the maximum sample time limitation, but instead allows the S700 to store a further 10 samples of the same maximum length in RAM.

Jumping Through Loops

The S700 is a little more flexible when it comes to sample editing. After the initial recording, samples can be trimmed or re‑sampled, just as you would expect, and there's also the more unusual option to 'overdub' a new recording on top of the original one. Overdubs can be used to build up very interesting (if somewhat noisy) textured samples quickly and easily, and without using any extra memory.

In addition, the sampler provides a good selection of looping options. Loop points can be searched for automatically, and when suitable ones have been found a sample can be set to loop in a variety of ways. As well as conventional sustain looping and a one‑shot 'drum‑trigger' option, the S700 also offers 'alternate' looping — where the sample data between the loop points is played alternately backwards and forwards until note‑off. This feature, long‑beloved of S950 users, is great for creating click‑free sustaining pad sounds, and can also be used to very interesting effect on certain percussion loops. I can't imagine why Akai neglected to include alternate looping in so many of their later samplers — I would kill for an easy way to make my S2000 do this!

There's no proper ADSR envelope generator, but the S700 does offer a release‑time setting for looped samples. Release time can also be mapped to respond to key velocity, which allows for slightly more expressive and responsive voices.

The final weapon in the S700's armoury is a low‑pass filter, the cut‑off point of which can be modulated by key velocity. This can be used to mimic the properties of certain acoustic instruments, which tend to produce more high frequencies when hit or plucked harder, but sound duller when played more softly. Unfortunately, the filter has no resonance, and so cannot be used to produce acid‑y synth effects.

Hands On

Sampling with the S700 is reasonably straightforward. To create a new sample, press the 'New' button, set the desired pitch (between C0 and B5) and select a bandwidth for the sample about to be recorded. Bear in mind that the S700 thinks in terms of the bandwidth of the sample to be created, and not the sampling frequency that will be employed to create it.

Anyone familiar with sampling and digital audio will know that, as a rough gui de, you ideally need a sampling frequency of twice the highest frequency you want your sampler to record. The highest bandwidth setting available on the S700 is 16kHz, which suggests that the sampler has an effective maximum sampling frequency of 32kHz (though the manual states that it is actually 40kHz).

Once the required bandwidth has been chosen, you simply adjust the recording level to avoid distortion, set the threshold at which recording will commence, and press 'New' again. The S700 will begin recording as soon as the signal peaks higher than the threshold. How long it will record for depends on the bandwidth you've chosen.

Nowadays, 'CD quality' 16‑bit stereo sampling is standard even in entry‑level budget machines, but the S700 is a relic of a less advanced age. Like the S900 and S950, it samples in mono and using twelve bits. Consequently it tends to colour the sounds it samples much more noticeably than its modern counterparts. Twelve‑bit sampling yields a poorer signal‑to‑noise ratio and a reduced dynamic range compared with 16‑bit audio, and even at its maximum 16kHz bandwidth setting the S700 will struggle to faithfully reproduce the brightness of certain high‑frequency sounds.

This is not to say that the S700 sounds bad, but it does have a distinct character and some very definite limitations. However, if you're willing to work within these limitations, it can still perform well. You'll never get a convincing grand piano multisample out of it, for example, but it's quite capable of reproducing analogue basses or drum machine hits with a pleasing amount of warmth and punch.

For my money, however, it's when you reduce the bandwidth to something less than, say, 6.3kHz and sample a drum loop that the S700 really comes into its own. Bass drums pulse and thump, hi‑hat is reduced to a dull tick, and snares become crunchy explosions of something like white noise. Suddenly even the most uninspiring loops from sterile 'session drummer' sample CDs can be transformed into the kind of grainy, lo‑fi breakbeats that would make many a hip hop producer proud. Magical.

Walk The Dinosaur

Even the most ardent admirer of the S700 couldn't deny that it's starting to show its age. Its limited memory, comparatively low sound quality and lack of any really useful data‑storage device (see 'A Quick Warning' box) all conspire to make it seem horribly under‑powered by today's standards. Compared to even the cheapest entry‑level samplers currently available, it's a dinosaur — and I wouldn't advise anyone looking for a first sampler to opt for an S700.

So why do I still keep 2U of rack space free for my S700, in spite of the fact that its disk drive has been dead for several years? Why does it still make regular, prominent appearances in my tracks? Quite simply, because nothing else I own sounds like it. For all its imperfections, the S700 has bags of character. Whether or not you happen to like that character is, of course, a question of taste. Personally, I love it, and I frequently find myself bouncing slightly bland 'too‑perfect' samples from my S2000 over to the S700 just to warm them up a bit.

Skimming through a couple of dozen back issues of SOS, I couldn't turn up even one S700 for sale on the second‑hand market, so it's difficult to say what the going rate currently might be. Anyone looking to buy an S700 should bear in mind that they can probably pick up a more powerful, more expandable and in every way more useful S900 for around £200 — and that includes a disk drive you can actually use! Still, if, like me, you're a sucker for crunchy, lo‑fi samples and somebody offers you an S700 at a bargain price, I don't think you'll regret making space for it...

A Quick Warning

It's worth drawing your attention to the S700's disk drive, as it is not one of the now‑standard 3.5‑inch floppy drives that we all know and love. Instead, the S700 is blessed with an example of the strange and deservedly‑obsolete 2.8‑inch 'QuickDisk' drive.

QuickDisks, for those of you who may not have encountered them, are small, double‑sided disks with a less‑than‑awe‑inspiring total capacity of 128kb. For a couple of years they were the storage solution of choice for those green‑screen, sub‑PC word processors that enjoyed a brief spell of popularity before Microsoft Windows took over.

Needless to say, you can't fit much audio onto a QuickDisk. Some rather aged S700 sample disks that recently came into my possession contain just two neatly‑trimmed drum machine hits each — one on each side — with the whole kit spread over no fewer than eight disks!

While their limited capacity might be frustrating, the almost total non‑availability of QuickDisks these days is likely to be of greater concern for the average S700 user. If you're lucky you might be able to find some old, re–usable disks in a car‑boot sale or junk shop, but equally you might not. A better solution might be to look for some sample editing software for your computer that is capable of receiving MIDI sample dumps from the S700, such as Steinberg's Avalon (see retro review in SOS July '99) for the Atari ST.

Memory Is Made Of This

Nowhere in the S700's manual is it explicitly stated how much sample RAM is built into the machine. However, by referring to the specifications given in the back of the manual, it's possible to at least make an educated guess.

First of all, we know that the S700 is a 12‑bit sampler. In practice this means that twelve bits of data are used to represent every measurement or 'sample' of an incoming audio signal. We also know that the S700's maximum sampling frequency is 40kHz — which means that up to forty thousand of these 'measurements' can be taken in one second. Forty thousand 12‑bit samples are equivalent to 480,000 bits of data (12 x 40,000 = 480,000) or, to put it another way, 60kb (480,000 ÷ 8 = 60,000 — there are eight bits to a byte). Therefore, in order to be able to sample one second of audio at a sampling frequency of 40kHz, the S700 would have to be equipped with 60kb of sample RAM.

As we know, the S700 is actually capable of recording six 0.8‑second samples at its maximum bandwidth setting of 16kHz — which we will assume corresponds with the maximum sampling frequency quoted in the machine's specifications.

Six 0.8‑second samples amount to a total sampling time of 4.8 seconds and, if we're assuming that one second of maximum bandwidth audio requires 60kb of sample RAM, we can therefore conclude that the S700's 4.8 seconds of sampling time probably uses 288kb of sample RAM (4.8 x 60 = 288). If these calculations are correct, we can extrapolate that the ASK70 expansion board — which allows the S700 a total of 16 0.8 second‑long voices — probably increases the total sample RAM to 768kb.