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Jomox Airbase99

Expander/Synthesizer By Chris Carter
Published August 1999

Jomox Airbase99

Jomox's Xbase 09 was a clever and eye‑catching modern alternative to an expensive vintage Roland TR909 drum machine. Now the Xbase sounds, plus more, are back, in a rackmount module designed for those who prefer to program drum patterns using their own sequencer. Chris Carter airs a few opinions.

Jomox have always had a fairly low UK profile and their wonderful little beatbox, the Xbase 09 (reviewed SOS June 1997), never really fulfilled its full potential, becoming a cult item rather than achieving the widespread success of which it was worthy. But now Berlin‑based Jomox are back with a new distributor and a brand‑new (ish) product. It's described by Jomox as both a drum expander and a drum synthesizer, but the latter is a more accurate description of this MIDI‑controlled hybrid analogue/digital drum expander module.

Back To Base

The AiRBase99 offers a dedicated output for each voice, as well as a stereo output — and all operate at the 'pro' +4dBu level.The AiRBase99 offers a dedicated output for each voice, as well as a stereo output — and all operate at the 'pro' +4dBu level.

The majority of the AiRBase99 sounds are derived from the earlier TR808/909‑inspired Xbase 09, and have almost identical audio characteristics. The kick and snare drums, in particular, are said to be exactly the same as those on the Xbase 09. There are differences between the two machines, however, one of the most obvious being that the AiRBase99 is capable of playing back nine percussion voices simultaneously (kick drum, snare drum, high and low toms, hi‑hat, clap, rimshot, crash and ride cymbals), whereas the Xbase 09 had a fairly measly 3‑voice polyphony. The AiRBase99 also features additional percussion voices and samples, modulation LFOs, and an increased memory of 500 preset ROM kits and 1024 User RAM kits. However, it's missing the plethora of knobs and rhythm‑pattern features of the Xbase 09. You win some, you lose some.


As you can see from the accompanying photo, the AiRBase99 is housed in a 1U rack module. This is a nicely constructed, substantial unit which, being made from steel, is quite heavy for its size. The front panel is pretty sparse, with just a power switch, six small illuminated buttons (Master, Edit, Play/MIDI, Enter, plus two cursor buttons), a continuous data knob, an illuminated 2‑line x 16‑character LCD, a volume control, and a headphones socket. The rear panel is an altogether busier affair, with a main stereo mix output on two jack sockets, 10 individual audio outputs, MIDI In, Out and Thru, and AC power in. Disappointingly (considering how much space is available internally) the AiRBase99 uses a bulky external 12V AC adaptor. Be warned that replacement AC adaptors can be much harder to locate than their DC brethren, should they ever fail!

Analogue To Digital

As hinted at above, the AiRBase99's percussion sounds are divided pretty equally into analogue and digital types, with the kick drum, snare drum, high and low toms all being analogue. The AiRBase99 doesn't use any new‑fangled analogue‑modelling techniques for its analogue sounds. Instead it relies on tried‑and‑tested authentic discrete analogue circuitry under digital control, allowing for some impressive and powerful dynamics.

The hi‑hat, clap, rimshot, crash and ride cymbals are all generated digitally and stored in ROM as 8‑bit samples. Each of the four digital instrument voices can play back one of four sampled variations: 808, 909, CR78 and JMX (the JMX variations are samples of real sounds, not beatbox sounds). Each sample is processed by a simple analogue VCA/AR (Voltage Controlled Amplifier/Attack‑Release) combination, and the hi‑hat samples can be further modified by two resonant filters (2‑pole high‑pass and low‑pass).

I didn't have an original Xbase 09 to directly compare, sound‑for‑sound, with the AiRBase99, but I had a few banks of sampled Xbase 09 percussion voices from my previous encounter with it. I found the overall sound to be even punchier and more dynamic than the original Xbase 09, but of course that could be attributable to my sampling. The analogue drums still sound mightily impressive, and some extremely wide‑ranging sonic acrobatics are possible, far out‑performing the already impressive sounds of the original TR808 and TR909. The welcome inclusion of low and high toms, claps and rimshot are all useful additions to the already fine‑sounding kick and snare.

I'm not so sure about some of the new digital samples, though; in their raw state a few sound a little flat and uninspired, which could be due to the 8‑bit sampling. But if you spend time editing it's possible to coax something interesting out of most of them. This is where the individual outputs become essential, as you can dedicate a mixer channel to each percussion voice, giving a lot more scope for further manipulations with EQ, compression and effects. It's worth noting that the outputs run at the hot 'professional' level of +4dBu rather than the alternative and widely used ‑10dBv semi‑pro level. So be careful out there!

ROM Raiding

Editing the AiRBase99 is a little idiosyncratic. If you decide to edit a preset ROM kit you'll find that even though the display will ask if you wish to save your edit (and, confusingly, let you press 'Yes'), if you return to the preset later all your tweaking is lost. Frustratingly, you're not given the option to save the kit to another location either. The Jomox 'way' is to copy a ROM preset to one of the user RAM locations before editing it, which can be a little tricky, as it's not entirely obvious which bank you're copying into. This is a bit of a roundabout way of getting down to business, but once you have a kit in RAM you can edit and save to your heart's content.

There are more than enough percussion‑voice editing parameters to work with, particularly for the kick drum and hi‑hats. The kick drum alone has at least a dozen parameters, including Tune, Pitch, Decay, Harmonics, Pulse, Noise, Attack, Level and Velocity, while the hi‑hats go several better, with around 15 parameters, including Tune, Closed and Open HAttack, Closed and open HPeak Time, Closed and Open HDecay, HSample Select, Reverse, High‑pass and Low‑pass Cutoff (see the 'Drum Voice Editing Parameters' box for a full list for all the voices).

Most of the parameters are self‑explanatory, but the Attack and Peak Time parameters do need some clarification. Confusingly, the Peak Time parameter actually sets what is called attack time by 99 percent of instruments, while the Attack parameter adjusts the overall level of the Peak Time parameter. OK? (For a more detailed description of editing the sounds, check out my review of the Xbase 09 in SOS June '97). Selecting Initialise for any of the percussion voices resets it to a default TR909‑type sound.

There are also system‑wide editing parameters, which include receive and transmit MIDI channel settings, kit naming, LCD contrast, memory protect (which, unusually, is applied on a kit‑by‑kit basis), and overall BPM/LFO speed. Kits can be copied from bank to bank, or saved over MIDI using the useful Snapshot feature. This sends a short SysEx dump of all the settings for a selected kit to your sequencer. The MIDI snapshot can then be placed within a song and sent back to the AiRBase99 while the sequencer is playing, whereupon the current kit will adopt the stored sound settings. Backing up all the kits using MIDI SysEx bulk dump and load is also an option.

Modulations & Control

Each LFO can output a waveform to modulate the pitch of any of the percussion voices, and LFO1 can also control the hi‑hat filter‑cutoff parameter. If required, both LFOs can modulate the same destination. Waveforms available are sawtooth (normal and inverted), triangular, and square (here called Rectangular). The rate of the LFOs isn't as wide‑ranging as it could have been, so no wild vibrato effects are possible, but the LFOs can be sync'ed to an incoming MIDI tempo or a user‑settable BPM figure. They can also be sync'ed to MIDI Note On messages. Each LFO has an output‑level parameter, but I would have preferred to see a more versatile approach — namely, separate LFO input‑level parameters for each percussion voice.

As with the Xbase 09, full control of almost every AiRBase99 editing parameter is possible over MIDI. Because it doesn't have a pattern sequencer, the AiRBase99 can't quite match the versatility of the original machine, but if you connect it to a computer sequencer you can achieve almost the same results, but with more percussion voices. A couple of annoying omissions are a voice‑panning parameter for the stereo mix output, and an overall output‑level control, whether software or hardware. The AiRBase99 doesn't respond to MIDI volume controller 7, and the volume‑control knob on the front panel only adjusts the headphone level.

No Expensive Knob Gallery

According to their literature, Jomox have introduced the AiRBase99 for "musicians that are difficult to separate from their beloved sequencer software programs and that ridicule old‑school internal step sequencers, looking upon them with suspicious, unbelieving and critical eyes... Instead of sporting an expensive knob gallery, all parameters on the AiRBase 99 are controllable only via MIDI." Hmmm.

Add these words to the fact that the AiRBase99 ships with editing templates and mixer maps for Cubase, Logic and Vision computer sequencers, and you can see that Jomox are positively encouraging users to program the AiRBase99 externally. This is understandable, because, although it's not particularly difficult to program, the combination of limited LCD information and the nature of multi‑page menu structures make that programming laborious and time consuming. Editing the hi‑hats alone involves eight pages of parameters. However, the helpful instruction manual has a good index, is clearly laid out, and includes plenty of useful MIDI‑related information for the adventurous programmer.

I imagine most users without access to a computer will resort to using one of the many preset kits, or just tweaking and customising a few, rather than building new ones from scratch. If you do have a computer, the picture is a lot brighter. The supplied editing templates are pretty good, and new ones are also in development (they'll be available from the Jomox web site soon). The manual also contains more than enough MIDI controller information to allow you to build your own templates, if you're that way inclined. Alternatively, you could use a hardware editing solution such as the knobbly Doepfer Drehbank, Kenton Control Freak or Keyfax Phat Boy, though unless you already own one of these this could be a rather expensive editing solution. On the other hand, once you've completed all your editing the kits are quickly and easily accessible from the front panel or via MIDI program changes.

Repackaged Deal

The increased memory, LCD, 9‑note polyphony, extra outputs, additional drums and samples, and LFO modulation are welcome improvements over the Xbase 09, but when I first heard that Jomox were bringing out a new drum module I assumed it would be something a little different. It's obvious that the AiRBase99 is essentially a repackaged Xbase 09 without the user‑friendly, hands‑on programming of the original. There are some very good preset kits to choose from but some do have a tendency to sound a little samey, no doubt because of the limited number of percussion samples available. Also, although there's no question that the AiRBase99 is capable of producing some extremely unusual and dynamic percussion sounds, some of the samples are beginning to sound a little dated, and it would have been nice if Jomox could have been a bit more creative in this department. I'm not entirely convinced that dance‑based musicians still consider the retro TR808/TR909/CR78 sound quite as essential to a mix as it was two years ago.

The original Xbase 09 was a quid short of £700 and seriously close to being overpriced, while the AiRBase99 costs £500, give or take a pound. Personally, I couldn't quite justify that much for what's on offer, but for the professional remixer or producer the value‑for‑money equation isn't such an issue, and it's obvious that some of the AiRBase99's features are aimed at pro users — the +4dB audio outputs and the substantial, industrial‑strength steel case, for instance.

The AiRBase99's biggest hurdle is going to be competition from the likes of the recently price‑reduced Alesis DM5 drum module (reviewed in SOS February 1996 and currently around £269) and the Korg Electribe ER1 (£349, reviewed last issue). Although the Electribe uses analogue modelling and digital samples, it's still capable of sounding very similar to the AiRBase 99 and offers a hands‑on approach to programming that's similar to that of the original Xbase 09.

Fill the AiRBase99 with your own kits and drum sounds and you'll undoubtedly have a powerful and professional instrument, that is equally at home on stage or in the studio, at your command. If you don't have an original Xbase 09, TR808 or TR909, the AiRBase99 could have just the sound you're looking for — in the right hands it can really kick. My advice would be "try before you buy."

Brief Specification

  • Kits: 1024 User RAM, 500 Preset ROM.
  • Polyphony: 9‑note.
  • Filters: 2‑pole resonant high‑pass and low‑pass.
  • LFOs: 2, assignable.
  • MIDI: In, Out, Thru.
  • Outputs: 10 individual, stereo mix, headphone.
  • Display: 2‑line x 16‑character LCD.
  • Power Supply: External 12V AC adaptor.

Drum Voice Editing Parameters

  • Kick drum: Tune, Pitch, Decay, Harmonics, Pulse, Noise, Attack, Level, Velocity, Scale, Linear, Semitone.
  • Snare drum: Tune, Snappy, Decay, Detune, Noise Tune, Level, Velocity.
  • Toms: Tune, Decay, Level, Velocity.
  • Hi‑hat: Tune, Closed HAttack, Closed HPeak Time, Closed HDecay, Open HAttack, Open HPeak Time, Open HDecay, HSample Select, Reverse, Source, High‑pass Cutoff, Low‑pass Cutoff, Resonance, Level, Velocity.
  • Clap, rim, crash, ride: Tune, Attack, Peak Time, Decay, Sample Select, Reverse, Level, Velocity.

AiRBase99 Instruments


  • bass drum.
  • snare drum.
  • high tom.
  • low tom.


  • hi‑hat.
  • clap.
  • rim‑shot.
  • crash.
  • ride cymbal.


  • Dynamic, versatile and authentic retro sound.
  • Increased polyphony over Xbase 09.
  • 10 individual audio outputs.
  • Sizeable ROM and RAM kit memory.
  • Well‑specified MIDI control options.
  • Sturdy, well‑built case.


  • Laborious to program without a computer.
  • Limited number and variety of samples.
  • No trigger inputs.
  • No voice panning.
  • External AC adaptor.


A drums‑only, stripped‑down and repackaged version of the Xbase 09 cult classic that sounds even better than the original. The additional percussion voices, samples, LFOs, LCD and increased kit memory are all welcome, but the sacrifice has been rhythm patterns and ease of programming. However,if you're prepared to invest some extra time programming, it could be a worthwhile addition to any professional setup.