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Zoom RhythmTrak 234

Drum Machine
Published May 1998

Zoom RhythmTrak 234

New drum machines are few and far between these days, but as Nicholas Rowland discovers, this one has a lot to offer even in a world full of computer sequencers.

In this sequencer‑driven, multitimbral world, you would think that beat boxes might have hung up their virtual drumsticks some time ago, out‑gunned by alternatives which are often far more versatile and a great deal more expandable. However, the fact is that at the budget end of the music technology evolutionary scale the dedicated drum machine still has its place — for live playing, for non‑MIDI musicians, and for those times when you simply don't want to turn on two grand's worth of computer technology just to beat out a simple cha‑cha‑cha. That explains steady sales of models like the Alesis SR16 and the Boss Dr Rhythm series of drum machines. And it also explains why Zoom's first departure from the effects units for which they are justly renowned takes the form that you see here on these pages. Actually, 'drum machine' is a slightly too tight‑fitting phrase for the new RhythmTrak 234, as its subtitle — 'drums/percussion/SFX/bass' — might suggest. First, it offers loads of sounds: not just drums and percussion but melodic basses of all shapes and timbres. This in itself makes it interesting for guitarists, keyboard players and instrumentalists looking for a rhythm section. Second, it offers some novel ways of manipulating these sounds in real time. Third, along with its 99 preset and 99 user programmable patterns, it gives you the facilities to play with loops DJ‑style — building up and breaking down rhythms layer by layer. Fourth, all this is yours for a modest £199.

Plastic Fantastic

The RhythmTrak is sounding good before you even start to remove the packaging. Take it out of the box and it looks very good indeed. It's a well‑designed piece of kit, with a low‑profile grey plastic case and the fan‑shaped arrangement of the main drum pads giving it, to my eyes, a pleasing, slightly futuristic appearance, like something you might expect to play a crucial part in the plot of a Star Trek movie. On a more down to earth note, the RhythmTrak also feels as though it has the mettle to stand up to the kind of (un)fair wear and tear that drum machines usually experience in their lifetimes. The rectangular shape of the 13 drum programming pads makes it easy to tap them with two fingers — ideal when you feel the urge to simulate the opening bongo roll from the Pearl & Dean theme tune. They are also velocity sensitive, with a choice of seven sensitivity options. Above each pad — and, indeed, above most of the other buttons — is a tiny LED which lights whenever that pad is played or whenever the sound assigned to it is triggered. This is extremely useful when you're editing a drum pattern which uses lots of different sounds, as it enables you to quickly identify which pad/sound combination is playing. As the drum pads are also used to access many of the machine's programming features, these LEDs also help you keep track of which editing function is live at any one time. With clear labelling, a logically laid out front panel and the main 6‑digit, 7‑segment LED in the centre of the unit, the RhythmTrak is very easy to get to grips with, even without recourse to the manual. And as I didn't have a manual for most of the review period, I speak from experience.

Around at the back you'll find a power switch, the input for the supplied 9V transformer (wall‑wart alert) and a small rotary control for overall volume. Along with these are stereo outputs on quarter‑inch jacks, an audio input, two inputs for control pedals, and a MIDI In socket. The lack of a MIDI Out did cause me to raise a few eyebrows — or, more correctly, to raise my two eyebrows several times. However, as the RhythmTrak 234 is aimed primarily at the solo instrumentalist, or the gigging musician, rather than at the fully fledged MIDI studio muso, I'm sure most potential users won't see this as a disadvantage. That said, I would like to have seen at least one more auxiliary output, particularly on a unit offering melodic bass sounds, since these are often likely to require separate processing from the drum sounds.

The RhythmTrak is an excellent debut outside the company's usual sphere of operation.

Sounds Good

The RhythmTrak has a total of 174 basic sounds, including the basses, which are assembled in various combinations to give 124 drum kits and 50 melodic bass patches. The styles into which the kits are grouped (displayed on the front panel) show that the emphasis is firmly on contemporary popular styles — rock, funk, hip‑hop, techno and rap. That's confirmed by preset patterns which cover styles such as rock, thrash, metal, punk, techno, acid jazz, hip hop, funk, big beat, R&B, ska etc... not a paso doble or a Gay Gordon in sight. It'sall competent (and occasionally inspiring) stuff. As each preset comes with an appropriate bass line, they're great to jam along to. Each kit consists of 13 instruments, with the first 100 kits comprising conventional collections of drum sounds — in other words, bass drum, snare, three toms, hi‑hats, crash and ride cymbals, with the rest of the numbers usually made up with latin and ethnic percussion sounds. The last bank of 'Percussion/SFX' kits consists of collections of more exotic sounds, ranging from temple blocks, tablas and gamelan, to off‑the‑wall FX such as thuds, squeaks, ghostly howls and reversed cymbals. Among this list you'll also find a brush snare set, classical orchestral collection, and a set of cymbals. Overall, the individual sounds are excellent, and many of them also have a distinctive, slightly grainy character which is not unappealing. There are plenty of crowd‑pleasers in the form of big ambient rock drums, feisty hip‑hop kits and snappy techno sounds. The TR808 and TR909 imitations are pretty good, with the bass drums in particular having plenty of bottom end. And among the ethnic percussion you'll find some of the best drum machine tablas I've ever come across.

A RhythmTrak pattern can make use of any combination of three drum kits, plus one sound from the bass bank (each one of these pattern elements is henceforth known as a track). This means that for each pattern you have access to a total of 39 drum sounds, plus bass. Note that the kit and bass assignments are memorised as part of the pattern data, so switching to a new pattern brings up the appropriate kit selections. You can also program an overall volume for each track and save that as part of the pattern data.

A Pattern Is Emerging

Even if you haven't used a drum machine before, you'll find the pattern programming and playback functions very easy to get to grips with. Both step‑time and real‑time recording are available, with the basic stop, start, pause and record duties handled by four tape transport‑type buttons in the top right‑hand corner. Pattern length is programmable between 0 and a generous 99 bars, although options for time signatures are rather restricted at 2/4, 3/4 and 4/4. Progressive jazz rockers will have to look elsewhere. Possible quantise values are 4, 8, 12, 16, 24, 32, 48 and Hi (in other words, quantise off), with 16 being the default. The quantise value also determines the timing of the auto‑roll function (controlled by the elongated repeat/step key below the drum pads) as well as the length of the rests when inputting in step time. You can also apply a swing function, to shuffle‑ise the pattern, and make offset‑timing adjustments to give the pattern more of a human feel. Tempos can range from 20‑250bpm, and it's good to see that the RhythmTrak has a tap tempo function, which was often lacking even from more expensive drum machines of yore. With facilities such as programmable count‑in and click volume, plus an easy delete function (both for individual instruments and whole patterns), programming the RhythmTrak really is very straightforward indeed.

Shaping Up

During programming you can make use of the Sound Jammer function — the slider on the left‑hand side of the panel — which allows you to continuously adjust the pitch, volume and tone (known in RhythmTrak speak as 'Sound Change') of individual instruments as you record. Pitch and volume behave in much the way you'd expect. But the effect of the 'Sound Change' function varies from sound to sound. In some cases, moving the slider up will lengthen the decay and increase the attack of a sound. In other cases, it will allow you to crossfade between two variations of the same sounds — for example, between a ride cymbal 'surface' sound and a ride 'bell' sound, or between a closed and open hi‑hat sound. At other times you can toggle between two completely different sounds — a clap and a cowbell, for example. This is a great tool, even though you are restricted to just one Sound Jammer function at a time. You can also use the Sound Jammer function when playing the pads along with a pre‑recorded pattern or song. However, it has no effect on the pre‑recorded pattern itself during playback. Incidentally, when the Sound Jammer function is not activated, the slider doubles up for virtually all other data entry functions — another factor which makes the RhythmTrak easy to use.

Feel A Song Coming On?

Songs are assembled from blocks of user patterns. Technically, you can't use the preset patterns in this way, though you can get round the restriction by copying presets to user locations. Each song can consist of up to 255 steps (one step equalling one pattern) and the RhythmTrak can store up to 99 songs. Tempo and volume changes can be stored as part of the song, while bass tracks can be transposed up or down by up to six semitones. With these parameters at your disposal it's possible to construct fairly complex backing tracks for, say, a live performance. As with all hardware sequencing devices, though, the real limit is available memory. In the RhythmTrak's case this weighs in at a reasonable 13,000 notes.

Getting Into The Groove

While the concepts of pattern and song programming should be fairly familiar, pressing both song and pattern buttons on the RhythmTrak allows you to explore stranger territory: RhythmTrak's world of groove play — described in the manual as playing with patterns "like a DJ spinning records". You can assign any of the RhythmTrak's 99 groove loops, or any of the 99 user‑programmed patterns, to any one of the 13 drum pads. The pattern starts playing as soon as you touch the pad, and if you touch the black bar as well it will continue to loop until you stop it by pressing the drum pad again. You can build up and break down percussion tracks layer by layer, with a maximum of four patterns playing at a time. Once again, those tiny LEDs keep you, the customer, informed at all times as to which pad is active. However, you will need a good memory, as there's nothing to indicate which loop is assigned to which pad. You will also need a good sense of timing and accurate button tapping skills, as the various loops don't automatically lock in with each other — they just start whenever you hit the pads. This is a source of potential embarrassment or a great creative bonus, depending on (a) your rhythmic abilities or (b) your sense of creativity. Those whose (b) outweighs their (a) might be interested in the prospect of assigning the same loop to two different pads, then starting the second one, say, a beat or two after the first to create impressively complex polyrhythms. Like the preset patterns, the preset loops cover a multitude of 'modern' styles: impressive big beat and hip‑hop workouts, delicate ethnic percussion lines, thumping bass lines and twiddly arpeggios. You can also alter the global pitch, volume and tonal characteristics of the loops in real‑time via the Sound Jammer control. However, this is something of an imprecise science: only those with a good sense of pitch will be able to manipulate the melodic loops to create something approaching a tune. Nevertheless, it's a great function and you can have lots of fun...

Above The Din

Judging by its single MIDI In, I wasn't expecting great things from the RhythmTrak's MIDI specification, but in fact I was pleasantly surprised by how comprehensive the spec is. Each of the three drum kits assigned to a pattern can be triggered over a separate, programmable MIDI channel, as can the melodic bass patch. A special Auto mode for the bass means that when the RhythmTrak receives a GM sound source bass select message, it automatically switches the bass track to the appropriate MIDI channel. Kits and basses can also be called up using pre‑assigned program change numbers. In the sync department, the RhythmTrak 234 will slave to an external MIDI clock and recognise MIDI starts and stops. All the Jammer parameters can be accessed via MIDI and all the sounds will respond to pitch bend — what more can the creative rhythmster want? What you can't do, though, is program patterns remotely — in other words, record a bass line using a keyboard. And obviously the lack of a MIDI Out also means that you can't dump RhythmTrak data to any external devices or use it to trigger external modules.

Along with MIDI control, you can also access the Jammer functions via a continuous controller footpedal (such as Zoom's very own FP01). An on/off footswitch type (such as the Zoom FS01) allows remote starting and stopping of playback too. You can also program the unit so that a pedal of this type will trigger any of the sounds or switch between two specified sounds. This last function allows you to switch between an open and closed hi‑hat sound, if, for example, you were using the RhythmTrak 234 as a sound source with MIDI‑fied drum pads.


I raise my hi‑hat to Zoom. The RhythmTrak is an excellent debut outside the company's usual sphere of operation. Indeed, given its highly competitive price, I'd happily live with the RhythmTrak's failings, which, I must stress, are relatively few. The bottom line is that the RhythmTrak not only delivers a lot for the money, but manages to come up with several new twists on what you would have thought is now a very tried and tested formula. To paraphrase Zoom's corporate slogan: Catch it if you can.

A Suitable Bass For Treatment

Calling up a bass patch assigns it chromatically across the 13 pads in semitone steps. In default mode. E2 is the lowest note. You can transpose the patch as a whole, or set individual notes for each pad, in a range from A1 to A4. These settings are then memorised as part of the pattern. Another useful function is the fine‑tune facility, offering a 435Hz‑445Hz range. There's a very comprehensive set of bass sounds, ranging from twangy Indie‑style bass guitar samples to pumping analogue synth soundalikes. In between, there are funk pops and slaps aplenty, hybrid bass/percussion sounds, and a rather impressive gritty bass slide. The Sound Change function allows you to further express yourself by bringing out the resonance on synth basses or beefing up the bottom end of acoustic guitar samples.


  • Easy to use.
  • Great looking.
  • Has bass sounds.
  • Innovative features, including real‑time 'jamming tools'.


  • No MIDI Out, which could be a problem for some users.
  • Lacks super‑detailed editing facilities.
  • The dreaded wall‑wart!


The RhythmTrak 234 offers a lot of bang (not to mention kick, snare, hi‑hat and bass) for the buck.