Zoom Sampletrak ST224

Derek Johnson & Debbie Poyser check out a product which offers up to four minutes of sample time, 22 different effects, audio processing and resampling facilities — for £199. If you'd been reading this only a few years ago, you'd have assumed that some digits had been missed off the price...

Yes, it's another one of those 'isn't progress wonderful — look at what we get now for tuppence that used to cost £10,000'‑type introductions. Well, it's unavoidable, really, when you're confronted with a little black sampling box that costs £199 and yields, at its best sampling rate, 30 times more sample seconds than Emu's original Emulator did, in 1980, for an eye‑popping £8000.

For those of you who don't fancy the maths, the Emulator managed two seconds of sample time, at 27kHz, back at the dawn of commercial sampling. Here, just before the dawn of the new millennium, the Zoom SampleTrak weighs in with 60 seconds at its highest bandwidth of 32kHz. Not that we're comparing the Emulator and the SampleTrak, of course. In sampling terms that might be a bit like comparing The Flintstones and The Jetsons: they're both good, but in very different ways. Yet perhaps there is one similarity worth mentioning: without the success of Hanna‑Barbera's stone‑age Flintstones, the studio's space‑age Jetsons probably never would have seen the light of day — just as, without the pioneering work of manufacturers such as Emu, perhaps you wouldn't be reading about the SampleTrak right now.

Meet The SampleTrak

The SampleTrak lacks a MIDI Out, so memory dumps can only be made to expensive Smart Media cards.

In the flesh — or, at least, in the matt‑black plastic — the ST224 SampleTrak actually looks a bit Jetsons. It's got curvy sides to its wedge‑shaped case, enough buttons and knobs to navigate Red Dwarf through a recalcitrant wormhole, and a smoothly rolling edit wheel set into a tactile sci‑fi dome. All in all, it definitely looks ready for take‑off.

Beneath the skin, the SampleTrak is capable of operating at three frequencies and thus quality levels: 32kHz, 16kHz and 8kHz. As mentioned earlier, the top rate yields a maximum of 60 seconds of sample time, and if you're prepared for reduced sound quality you'll squeeze out a pretty decent four minutes at the lowest rate. Individual samples at any sampling rate (mono or stereo) can't exceed half the maximum sample time at that rate — so a 32kHz sample can't be longer than 30 seconds, for example.

Eight rubber pads trigger samples, and a built‑in sequencer stores sequences of pad presses — up to eight sequences (Songs), with a total memory of around 5000 notes. The SampleTrak has a MIDI In, so samples can also be triggered by an external sequencer. However, there's no MIDI Out (bit of a Flintstones feel creeping in there), which compromises sample storage (see the 'Memories Are Made Of This' box).

The SampleTrak also offers 22 effects, which can be applied to samples and also, in some circumstances, used on external audio. The two editable parameters of each effect can be altered with the Edit 1 wheel and Edit 2 knob.

A large, six‑digit LED display is all that's available for navigating the SampleTrak's facilities, which are fairly comprehensive in light of its price. In practice the display is not too much of a problem, since most sampler facilities that require large graphic displays aren't available here in any case. 16 preset samples are provided, plus two demo Songs and a demo sequence, and though the Songs and samples can be overwritten, they can also be recalled later.

Sample Something Simply

Sampling with the SampleTrak could hardly be easier. Its stereo jack inputs are switchable for line or mic level, and once a sound source is connected it's only necessary to press the Record button, select sampling rate and stereo or mono operation, and set input level with the Input rotary. A red LED indicates overloading. Pressing Record again makes the SampleTrak swing into action, and pressing Play/Stop terminates recording. An Auto mode starts sampling at one of three preset threshold levels, and if you know the length of the audio to be sampled, the SampleTrak can stop recording at a user‑defined point.

The Play/Stop button will audition a sample, and then it makes sense to assign it, if satisfactory, to a pad — whereupon it becomes available for editing. If it's not up to scratch, erase it and start again. Not only can any single sample be assigned for triggering by a pad, but parts of a long sample can be assigned to different pads. This could be useful if, say, you were using a drum loop but also wanted access to some individual hits for adding over the top. However, it could be a little wasteful of memory — see the section on memory optimisation later.

Once a sample has been assigned to a pad, a number of 'pad parameters' can be set. These comprise sample start point and end point, level, tuning (+/‑ three octaves), pan, reverse (plays the sample backwards), and a trigger/gate option: the last sets whether a sample will play only while the pad is pressed, or play to its end even if the pad is released.

One thing you're certain to want to do, given a limited sample memory, is trim unused portions of a sample. That's where setting its start and end points comes in, as after this has been done the SampleTrak can Optimise — discard unused portions and free up memory. On a more expensive pro sampler, operations such as setting start and end points would be done with the benefit of a waveform display, and you might wonder how easy it's going to be with a 6‑digit LED job. Well, it's do‑able but a little frustrating. While a sample is playing back, start and end points can be set on the fly (by ear) just by pressing the Loop/Mark button — but unless your timing is fantastic, this probably won't be accurate. Fine‑tuning of start and end points is via the Edit 1 knob (coarsely) or the +/‑ buttons (in increments as small as one sample). You get there in the end! An alternative is mentioned in the manual whereby a sample end point is calculated in relation to a tempo value assigned by the user, but we found this rather inflexible.

As mentioned earlier, using a long sample and assigning bits of it to different pads can take up morememory than sampling the individual bits you want. This is because when the SampleTrak Optimises a sample, it only removes unused material at start and end. This means that it's more memory‑efficient to use several Optimised short samples than a long sample with unused material between its assigned sections.

Up to 32 samples (depending on length) can be stored in memory, though only 24 will be available at one time, via three 'pad banks' of eight pads each. Pad banks can be switched in real time, and samples from different banks can be used within one sequence. It's possible to assign a single sample to several pads, and you can even assign one sample to all the pads in a bank and apply the 'Major Scale' function. This tunes each sample to a different step in a diatonic scale and would enable the SampleTrak to be used for playing melodies with a pitched sound.

One thing you can not do with the SampleTrak is loop a sample, which might come as a bit of a surprise. However, it's possible to use the Loop/Mark button to make a sample play back repeatedly in a loop. This is a playback parameter and doesn't change the sample at all.

In other ways, though, the SampleTrak is surprisingly sophisticated. Take the Auto Sync function: this automatically matches the tempo of a pad to that of another pad, using time‑stretching (or pitch‑shifting, if you don't mind the pitch of a sample being affected). All you have to do is designate one pad Master and another Slave, and the SampleTrak does all the work. The time‑stretching option creates a new sample, which isn't the case with pitch‑shifting. Auto Sync works fast and results are very good, with tempo changes of as much as 20‑30bpm in either direction being usable. If you shift too far, there will be a noticeable change in sound quality, but you might find you like the effect. This isn't a machine which aims to offer the most pristine and sparkly samples, anyway, with a top rate of 32kHz rather than the usual 44.1kHz offered by most studio samplers.

Time‑stretching by itself is also available, but Zoom call it an effect — so we'll deal with it along with all the others.

A Suitable Case For Treatment

The 22 effects range from basic reverb and delay to mad ring modulation and distortion. Zoom use a rather loose definition of the word 'effect', also including scratching, filtering and resonance in the list. Only oneeffect at a time can be used, assigned to one or more pads, and set to work either just while the Effect On/Off key is held, or all the time. Sadly, there's no effect 'send' feature for adjusting effect amounts. A nice touch, however, is that some of the effects have a synchronisable element, so they'll play in time with the Song's tempo — for example, delay time, flange and phaser rate, and filter LFOs. This parameter is set independently of the Song tempo or incoming MIDI clock.

In context of a £200 sampler the effects are serviceable — the delay and reverb sound a bit grainy and cheap, but the modulation effects have much more of the Zoom feel familiar from their dedicated effects processors. Scratch has a stab at recreating turntable scratching (not too convincing), and the rather hackneyed Step Cry effect (sounding a bit like flange with sample and hold) might be known to you already, as it appears on many Zoom units.

We don't want to be too hard on the effects, because they're a bonus at this price, and the modulation effects, auto‑panner, filters, ring modulation and exciter are all pleasing and useful. The Volume/Bass effect, too, is great, beefing up the bottom end of a sample in the same way as the Exciter beefs up the top end. Shame you can't use both at the same time — though you could always resample after having used one, then apply the other to the new sample (more on resampling shortly). Lo‑Fi restricts a sample's frequency range and overlays a 'vinyl crackle', while Dimension acts like a stereo width enhancer, which could be good on all‑mono samples. Time‑stretching is a bit haphazard in operation, in that a 120bpm sample, say, can't be stretched to exactly 150bpm. You have to wiggle the Edit 1 knob until a sample's tempo seems right, which isn't ideal but is at least easy. The SampleTrak stretches samples in real time as the knob is moved.

Effects can also be applied to external audio fed through the SampleTrak using the 'Source' pad. This pad allows external audio to be mixed with samples — DJs could mix records with SampleTrak Songs, for example, and beginners could pass audio from a synth, say, through the SampleTrak without a mixer. Audio doesn't have to be effected, by the way — it can pass through dry.

Groovy Pads

Song Recording is Zoom's name for sequencing, with a Song being a sequence of pad presses. Nevertheless, this mode allows the composition of fairly sophisticated pieces — within the limitations of 5000 events and 300 bars for all eight sequences. The maximum number of mono samples that can sound simultaneously is eight; this figure is halved for stereo samples.

Using Song Recording is really just a matter of pressing Record and Play together, waiting for a metronome count‑in (if required) and hitting the pads in the desired order. Easy. However, there are a few things to set up before starting. A simple quantise resolves timing to one of six values as you play (though this can be turned off), so the relevant value needs to be set, as do song length (between one and 300 bars) and time signature (2/4, 3/4 or 4/4).

Usefully, the sequencer can be sync'd to MIDI clock, and the SampleTrak's pads can also be played from an external MIDI keyboard or sequencer. A neat feature for live performance is 'Playlist', which assigns each of the eight Songs to its own pad, enabling entire Songs to be triggered on stage. Pressing the Loop/Mark button makes the currently‑playing Song loop continuously until another pad is hit.

MIDI

The SampleTrak's MIDI spec is not that developed. A MIDI note number is assigned to each of the 24 pads, and you can change the MIDI receive channel. If you choose channel 10 — assigned to drums on General MIDI instruments — those notes are shifted up several octaves, taking them out of the way of the GM drum sounds. This is quite thoughtful, and means that beginners with a simple sequencer and one GM synth canadd the SampleTrak to their setups without needing more MIDI hardware. Otherwise, there's not a lot going on: no aftertouch, no pitch‑bend, no mod wheel, and no velocity (although Zoom maintain otherwise, our ST224 wouldn't respond to it). However, MIDI controllers are assigned to two effect parameters, effect bpm, and effect on/off; and effect types can be selected by program changes.

Dig further, though, into the MIDI spec at the back of the manual, and you'll also discover that Polyphonic Aftertouch can be used to reverse each pad's sample, alter its level and pan position, and enable effects. Almost no MIDI keyboard transmits Poly Aftertouch (where an individual amount is transmitted with each note number), but this data can be inserted into a sequence, and hardware controllers (such as Kenton's Control Freak) can be configured to transmit it. Just remember that you need a separate fader transmitting Poly Aftertouch on a specific note to get a specific effect. The sequencer responds to MIDI clock, with song position pointers.

One side‑effect of the lack of MIDI Out on this and Zoom's similarly styled ST234 RhythmTrak beatbox (see SOS May 1998) is that the two machines can't be synchronised together without another piece of gear to act as master MIDI clock. This is a shame, as the combination would be an excellent beginner's setup.

Encore Un Fois...

Probably the pièce de resistance (excuse our French) of the SampleTrak's feature set is resampling. Any sample or samples already on board can be re‑recorded as a new sample, complete with effects. This greatly expands the possibilities: memory permitting, an entire Song could be resampled, freeing up sample slots for new material and also allowing more than one effect to be used. It's also possible to resample at a lower sample rate to save memory or create special effects. The bummer is that you're unlikely to have enough sample memory to make the most of this feature, because you can't erase the samples you'd like to re‑record (thus freeing up memory for resampling) until the resampling has been done. Boss' budget SP202 sampler (see SOS January 1998) uses Smart Media cards to actually expand its memory, rather than just for offline storage, and this would have been a good idea for the SampleTrak.

All the same, resampling at this price is fabulous, and even using the lowest rate produces very interesting results. We actually preferred the depth and characterful grunginess lent to a harmony vocal sample off tape by the Lo‑Fi 8kHz rate.

On The Right Trak

The SampleTrak is definitely more space‑age than stone‑age. OK, you can't set loop points in a sample, there's not enough room for multisampling, no velocity crossfading, digital outs or synthesis‑type facilities. But you can resample, it has effects, it lets you freely mix sample rates and pitches (which other low‑cost samplers don't necessarily do), it offers up to four minutes of sampling, as opposed to the one minute of other budget samplers such as the Roland MS1 and Yamaha SU10, and it features time‑stretching and the novel Auto Sync. And it costs £199. You might call all of the above its Unique Selling Points. Anyway, it would be wrong to compare this unit with a studio rack sampler, because it's just not aimed at the same market or the same jobs.

In use, the SampleTrak is fast and friendly. The slim manual is so straightforward that you can read it in one sitting and have a good grasp of the unit. It's not so good for finding specific info fast, as it has no index and hides sometimes quite important facts in italicised 'Tips'.

Sound quality is always difficult to address, because what's fine for one person could be unacceptable for another. Even the top sample rate of the SampleTrak is a slightly less than perfect representation of the original, but this really doesn't matter for the kind of people who'll be buying it. It's close enough for jazz (or hip‑hop, or jungle, or industrial...). An A/B comparison would be necessary to pick out any sonic shortcomings at the top rate, and who's going to do that?

Zoom are probably aiming the SampleTrak at a wide spectrum of musicians, from experimenting guitarists (who already know the Zoom name well) to would‑be dance merchants buying their first sampler. But almost any hi‑tech musician, even the seasoned SOS reader with an established home studio, would probably like one of these, because it's so fun and immediate, as well as being the cheapest halfway‑serious sampling tool yet.