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Akai S20

MIDI Digital Phrase Sampler By Chris Carter
Published July 1997

The release of the S20 means that £500 now buys you into the prestigious Akai name — and gets you a supremely easy‑to‑use sampler which will perform both on stage and in the studio. Chris Carter goes completely loopy...

In an interview some years ago I was asked what I thought was the most essential piece of gear in my line of work, and without a second thought I said "a sampler". "Ahh", said the interviewer, "but aren't they instruments of the devil, don't they put musicians out of work, and wasn't a sampler responsible for that awful 'NNNNineteen' record?". OK guv, it's a fair cop. I admit everything, except the bit about 'NNNNineteen'.

For the hard‑up musician (aren't we all?) who can't afford banks of keyboards, a sampler is invaluable — with a decent sample library it can take on the guise of almost any instrument or sound, so I still stand by the answer I gave then. Give me a sampler, an effects unit and a DAT machine, and I'll give you a CD, a gig, or both. Death to the Luddites: long live the RAM chip!


Good‑quality samplers, on the whole, have never been what you might call affordable. Until now, that is, when along come Akai with an expandable, 8‑voice, 16‑bit stereo sampler, with a few novel features (including a basic real‑time sequencer and a useful automatic bpm‑calculation mode), for only £499. The S20 is essentially a repackaged hybrid of the original mono Akai S01 (reviewed in SOS November 1992), with some added Remix 16 (Akai's DJ sampler). It has the typical Akai look, unlike the Remix 16, and is compact but chunky, with a footprint a little smaller than the magazine you're holding.

Editing is achieved with the minimalist edit matrix approach first seen on the aforementioned S01. This arrangement uses two rows of LEDs, with printed columns showing which mode is current, and four cursor buttons to navigate around the matrix. There's a large 4‑digit display, with + and — buttons for entering parameters, and a coarse button to speed things up. A further eight buttons (Rec, Erase, Hold/Loop, Stop, All Stop, Reverse, Seq, Edit) cover the real‑time playback, record and sequencer functions, and there's a large Tap button for repeat triggering of samples, or for entering the bpm of a sample loop manually in Beat mode (more on this later). The Reverse button, by the way, allows you to instantly and temporarily reverse a loop or sample. Finally, 16 Bank buttons (unfortunately not velocity sensitive) are used to trigger the samples. The stereo inputs and outputs are on line‑level phono sockets and there's a quarter‑inch headphone socket. Power is supplied by a small 12V DC unit — not a wall‑wart type.

Before I go into too much detail about the S20, I should briefly explain a little about Akai's use of the term Bank. Each of the 16 Banks in the S20 contains one sample and a VCA — that's it. If you've used other Akai S‑series samplers before, these Banks are the equivalent of a single keygroup, containing a single stereo or mono sample. This begs the question: if Banks only contain one sample, why didn't Akai call them samples instead of Banks? Anyway, from now on, for Bank read sample.

Three Steps To Sampling

Out of the box the S20 is loaded with 1Mb of RAM, enough for only 14 seconds of mono sampling at 32kHz, but it can accept an additional 4Mb or 16Mb SIMM. With 17Mb installed, the sampling time jumps up to 131 seconds in stereo at 32kHz. Memory is dynamically allocated, so any Bank can use as little or as much as it needs — in theory you could have a single stereo loop over two minutes long at 32kHz, or even a sample over 17 minutes long in mono at 4kHz.

Sampling on the S20 is a piece of cake, and with its default settings it offers one of the simplest sampling methods I have ever come across, on any sampler. To sample and play back a stereo loop from a cold start involves only three button pushes: no parameters to set, no pages to wade through — just switch on and sample. Here's how.

Assuming you've already connected your sound source, a record deck or CD player, or, indeed, any line‑level signal to the S20's inputs, the first thing to do is press the Rec button, which puts the S20 in Record stand‑by mode and starts the Rec LED flashing. You can hear the audio signal and see how loud it is on the left‑hand row of Edit matrix LEDs, which now act as an input meter. Adjust the audio level (with the red Level knob) and choose whether to sample in mono or stereo. You can also select a sample rate (4kHz, 8kHz, 16kHz or 32kHz) and whether to use auto‑triggered sampling. However, to begin sampling at the default settings (32kHz, stereo) just press a Bank button and the Red LED glows steadily to let you know that you are now recording into that Bank. There are two ways to stop sampling, depending on whether the sound is to loop or not. Normally, pressing any button other than a Bank button ends the sampling, and the sample will play back if you press the same Bank button again. However, things get more interesting if you want to sample a loop. To stop while sampling a loop involves hitting the Hold/Loop button at the point where you want the sound to start looping. This seamlessly ends recording and starts playback of the sample, which is now in Loop mode, so you can hear the results immediately. This is a really fast and efficient way of achieving decent loops of any kind.

Completely Loopy

Successful looping on any sampler is an art, and that old idiom 'practice makes perfect' is just as true on the S20 as it is on an S3200XL. There is also often a 'knack' involved, and for the first few days of using the S20 I had it. It seemed as if I had magic fingers, because almost every loop I attempted worked first time, no matter what the tempo or style of music. Then I got flu for for a couple of days and nothing would loop properly — it wasn't the fault of the S20: I had acquired a woolly‑headed feeling and lost my sense of timing, and the knack of hitting those buttons just right was gone (I feel a lot better now, thank you).

Even though the S20 may be considered a basic sampler, there are enough parameters available to allow you to achieve pretty decent loops, including Sample Start and Length and Loop Length (all with fine and coarse adjustment) but, because of the simplistic 4‑digit display, manual loop adjustment on the S20 can be quite laborious. It's well worth trying to get a loop right while sampling, even if it means attempting the job two or three times. Achieving a good loop through careful timing means you can move on to grabbing and looping more samples a lot more quickly, because you don't need to get side‑tracked into Loop Edit mode to tidy things up, which can be a slow and frustrating process.

Other options available in Edit mode are Sample Tune, Transpose, Loop/One Shot and Release. Unfortunately there isn't any ADSR (Attack, Decay, Sustain, Release) control, only Release, so there aren't that many options for shaping a sample once it's inside the S20. An annoying quirk is that if you attempt to transpose or tune a sample that has been adjusted with the Beat Loop function (about which I'll tell you more in a moment), it goes out of sync.

Although sample editing on the S20 is hampered by the meagre display, there are still quite a few options available. In Trim mode you can edit the start and length of a sample, to the minutest amount if needed, by using the Coarse and Fine parameters. Discard mode allows you to permanently remove areas outside the start and end points of a sample — the bits you can't hear. It's always good practice to do this, as it frees space and makes the most of the available memory.

A sub‑page of this mode is Copy, which allows you to copy one bank to another. Copy is also useful for making temporary backups of samples, prior to editing, and is a lot quicker than backing up sounds to disk. There are two other sub‑pages here: Reverse, which does what it says; and Initialise, which erases a sample and resets the parameters in the current Bank. Other edit parameters available are: Sample Level; Fine Tuning; Constant Pitch; MIDI Velocity Response; MIDI Bend Amount; Mono or Multiple Triggering. There is also a Resample mode, which can progressively downgrade a sample to a lower bandwidth, to conserve memory.

Beats Working

While I'm on the subject of looping, I should go into that Beat Loop function, because you can't really have one without the other in the S20. By using the Beat parameters you can match loops with different bpms to each other. There isn't any fancy time‑stretching going on here — just raising and lowering the playback speed of the sample — so loops can sometimes sound out of tune, but all the adjustments are calculated for you by the S20. To achieve this trick you need to enter a beat count figure (anything from 1 to 64) then the S20 measures the length of the sample, calculates the bpm and displays what it thinks the current sample bpm is, instantaneously. You then enter a new bpm, either manually or by using the Tap button, and the loop is instantly recalculated to that figure — pretty impressive. Well, it would be if it came up with the right bpm, but the S20 often displays a slightly different bpm. A loop at 128bpm, for instance, could be calculated as 127.1 or 128.9 — not out by much, but enough to make things fall out of sync over time. Apparently, these discrepancies are due to how accurately you've edited the sample length: although a loop may sound fine by ear, the S20 may not agree. After a lot of annoying (and unnecessary) loop adjustments and sample editing, it occurred to me that if the S20 insisted on telling me that a loop's speed was 127.1bpm, when I knew for a fact that it was 128, I should set a new tempo for my other loops (which were 120 and 135bpm) of 127.1bpm. Voila! Everything was now in sync, happy, happy, joy, joy... If the bpm needs further adjustment, it's just a matter of changing the Master Tempo setting, which shifts the tempo of all the loops relative to each other while still keeping them in sync.

It's a shame that the manual doesn't explain the Beat Loop function as well as it could (less than one page), considering that it's such a big selling point. Although it isn't foolproof, it's possible to get some impressive results if you are aware of its quirks.

Real Time

Although the S20 real‑time sequencer spec looks good on paper, with 30,000 notes across four tracks, it's a bit of a mixed bag and is only really useful as a musical scratchpad. Apart from the fact that it only offers Record, Play and Stop controls, if you try to get clever with your paradiddles it tends to throw a wobbly and its timing flies out of the window. The review unit also had a strange tendency to leave some samples muted when All Stop is pressed. The S20 does record the Bank Hold and Reverse functions but it doesn't record the neat repeating effect you get from pressing the Tap button (see 'Totally Tapped' box) and, unfortunately, doesn't receive or transmit MIDI start, stop or clock signals, although the front‑panel buttons can be controlled by a MIDI sequencer or keyboard. However, it does transmit MIDI note data, so you can transfer any sequences tried out on the S20 to another sequencer for more sophisticated editing.

MIDI Control

This brings me nicely to using the S20 as a multitimbral sampler module — though Akai don't seem to be as interested in emphasising this aspect of the sampler as they are in promoting it as a DJ tool. Setting up the S20 to receive MIDI on multiple channels is just as easy as everything else on this unit. I managed it without referring to the manual, which can't be said of many samplers. Under MIDI control, the S20 takes on a different personality altogether. For a start, it now responds to velocity and MIDI note numbers (across 10 octaves) on all 16 Banks. Each Bank can receive on different MIDI channels or share the same channel, with the facility to assign samples to specified ranges on a keyboard. So, for instance, with an external sequencer and keyboard connected, on MIDI channel 1 you could have a sample (not a loop) playing a bass line in the lower octaves and another sample playing a melody higher up, with loops and percussion samples playing on other MIDI channels. Important samples, such as drum loops, can be given higher priority over others, so that there aren't any embarrassing gaps if you exceed the S20's 8‑note polyphony.

Killer Hurts

At the 32kHz sampling rate the S20 sounds pretty damn good. I loaded some Akai S3000XL loops into the S20 for a side‑by‑side comparison and found little subjective difference — even the loop points played back perfectly. On the S3000XL, samples sounded a little more full, particularly in the sub‑bass area, and they had slightly more sparkle in the upper regions, but I think most everyday users would be hard‑pressed to tell the difference between them. However, with the S20 at 16kHz the sound quality isn't nearly as bright and has a distinctly digital graininess — though this rate is still perfectly acceptable for things like bass samples/loops, kick drums and SFX. At 8kHz, the sound quality becomes dirty and grungy, great for lo‑fi loops. The 4kHz setting has pretty limited usefulness.

Carry On Sampling

I haven't had so much fun sampling and looping for ages, and using the S20 is a piece of cake even for a newcomer to sampling. After using it for a day I knew where most of the deeper edit sub‑pages were without needing to refer to the manual. My 15‑year‑old son got his hands on the S20, and within ten minutes, without any help from me and not a peek at the manual, he was triggering, looping, reversing and layering samples. It took me another half an hour to get it back so I could carry on with this review! Most users will be flying this machine with ease after a week or so, because, even at its most complex editing level, the S20 is very easy to get to grips with. From switching on to sampling takes a mere eight seconds, making the S20 perfect for quickly grabbing samples and assembling ideas that can't wait. Seasoned S20 users are sure to become sampling speed demons.

And Finally

The S20 is undoubtedly a wolf in sheep's clothing and a wolf wearing two hats, at that. On the one hand it's presented as a phrase‑sampling, live DJ tool, for grabbing loops and matching bpms, which it does extremely well. On the other hand, if it's expanded to the full 17Mb of memory and connected to a MIDI keyboard, it's a perfectly capable 8‑voice, 16‑part multitimbral sampler. Some may find the 4‑digit display a limitation, and the editing facilities may be a little on the basic side when compared to more expensive samplers, but this is compensated for by the ease of use and the sound quality, which, at 32kHz, is superb.

There are a few other sub‑£500 samplers on the market, notably the dinky Yamaha SU10 at £299 and the Roland MS1 at £399, but neither of these offer Akai compatibility, which could be a deciding factor, considering the overwhelming amount of Akai‑compatible sample libraries available on floppy disk (see 'CD included' box). Whether you're a DJ or a musician thinking of entering the wonderful world of sampling, the S20 offers a pretty convincing combination of power and price, and could be a rewarding and productive addition to any setup, be it turntable or desktop. Just make sure you budget for some extra memory.

Messing About

While researching (for which read messing about) with the S20, I came across something even Akai UK weren't sure about: the S20 supports MIDI Sample Dump Standard — after a fashion. I managed to transfer samples to the S20 from an Akai S3000XL and from Cubase — a little slowly, but it worked. Strangely, the S20 wouldn't accept MIDI SDS files from Passport's Alchemy or Steinberg's ReCycle, and I couldn't persuade it to work in reverse at all.

Akai couldn't help, but they did say that some older Akai S01 editors and mixer maps may work with the S20, as it has a lot in common with the earlier machine.

CD Included

Included with the S20 are four HD disks of various loops and samples to get you started. In addition, with the UK package you get a free sample CD compiled by AMG, including hundreds of samples and loops from a dozen or so of the best AMG CD releases. There is so much stuff on this CD that it could take you a week to get through it all — everything from dub to disco, SFX, vocals, beats, bops and blaps, licks and loops, and all with listed bpms — icing on an already fine cake.


16‑bit stereo, 64x oversampling DAC

  • SAMPLING RATES: 4kHz, 8kHz, 16kHz, 32kHz
  • POLYPHONY: 8‑note
  • BEAT MODE: bpm adjustable from 000.1 to 999.9
  • MEMORY: 1Mb, expandable to 5Mb (with 4Mb SIMM) or 17Mb (with 16Mb SIMM).
  • SAMPLING TIMES: 1Mb, 32kHz rate: 7 seconds stereo, 14 seconds mono; 1Mb, 16kHz rate: 14 seconds stereo, 28 seconds mono; 17Mb, 32kHz rate: 131 seconds stereo, 262 seconds mono; 17Mb, 16kHz rate: 262 seconds stereo, 524 seconds mono
  • REAL‑TIME SEQUENCER: 4 tracks, 30,000 notes
  • CONNECTORS: L+R audio in and out (phonos); MIDI In and Out (soft Thru); Stereo headphones socket.
  • SIZE: 11.5 inches x 8 inches x 3.25 inches

Totally Tapped

Holding down the S20's Tap button and pressing a pad causes the very start of the sample being triggered by that pad to repeat rapidly (a bit like the dreaded 'NNNNineteen', but better). You can adjust the speed of the repeats using the + and — keys.

It's Storage, Jim...

The S20 is a fast machine to work with, and ideas can be developed and worked out very quickly. The only fly in this speedy ointment is the slow saving and loading to floppy disk. If you're sampling with the full 17Mb, in full flood with tons of great loops and sequences, and you want to move on to another song or try out some new ideas, you can't do anything until you've spent nearly 10 minutes shunting a dozen disks in and out of the S20 to back up your work. This tends to dry up the creative juices pronto, and I thought it seemed a bit short‑sighted of Akai not to have included the option to add at least either a battery back‑up, flash RAM or a SCSI connector — this machine is crying out for something like a Zip drive. However, after I had voiced my opinions to Akai they told me that the S20 is mainly intended for the DJ market — hence the inclusion of the Beat Loop function and the sample pads — and they see it more as a live looping tool, where saving and loading won't be an issue. They also anticipate that most people will go for the 4Mb upgrade rather than the full 17Mb, and in this case saving and loading will be a lot faster. Also, offering any of the above solutions (even as upgrade options) would have meant additional chips and a more detailed and expensive display, and this would have added too much to the cost of the unit.

I don't entirely agree with this: for a start, I think that many people will be tempted to go for the full 17Mb upgrade, particularly with the current price of RAM (approximately £75 for a 16Mb SIMM, if you shop around). Being multitimbral, the S20 is ideally suited for the GM/DTM market, which Akai do (rather half‑heartedly) admit. Also, after seeing my son's reaction to it, I can see a lot of up‑and‑coming electronic dance bands buying S20s and connecting them to MIDI keyboards as a cheap way into quality sampling.

As is usually the case in this industry, there will probably be a mark 2 or an XL version in a couple of years time; let's hope it includes some better external storage options. In the meantime, have fun!


  • Good‑quality 16‑bit stereo sound.
  • Expandable memory.
  • Fast, fun and easy to use.
  • 16‑part multitimbral.
  • Simple, logical layout, great for live use.
  • Small, well‑built and rugged.
  • Good price‑to‑power ratio.


  • No playback while sampling, saving or loading.
  • The 4‑digit display is a bit skimpy.
  • No panning of mono samples.
  • No ADSR envelope editing.
  • No metronome.
  • Saving and loading a fully‑expanded S20 will mean buying floppies in bulk.


A versatile, quality sampler let down only by the 1Mb basic memory and the 4‑digit display. At this sort of price, though, there's little to complain about. If you can live with these limitations, the S20 makes an ideal and reasonably‑priced introduction to desktop sampling, and if you're a DJ looking for a fast, easy‑to‑use looping machine with some useful dance‑orientated features, the S20 is a good choice.