First, let me go on record as stating that I love effects plug-ins and soft-synth applications. The cost savings they bring, alone, is a pretty darned

First, let me go on record as stating that I love effects plug-ins and soft-synth applications. The cost savings they bring, alone, is a pretty darned good argument against hardware. Still, you can't beat the hands-on appeal and reliability of hardware in my book. Sure, stuff happens, but the likelihood of encountering major OS crashes, dealing with corrupt system or application files or maxing out your processing power in the middle of a session is closer to zero with a box in your rack than with plug-ins in your folder.

Apparently, this was the underlying theory of the folks at Spanish DSP think tank Soundart when they created the Chameleon. The first commercial open-platform hardware tool of its kind, this 1U rackmount unit is perhaps the most flexible piece of audio hardware on the market today — and all for the cost of a typical high-end TDM plug-in.


In itself, the Chameleon is effectively a dumb box — a blank canvas, if you will. Unlike most digital studio hardware, it is not preprogrammed to act as any one type of device. Instead, true to the nature of its reptilian namesake, its identity changes with each new Soundskin, or aptly named code that manipulates audio and MIDI signals using the unit's raw DSP power. Load one Soundskin, and Chameleon becomes a multitimbral virtual-analog synth module. Load another, and it's a dedicated high-end studio reverb unit. Skin it again, and it's a guitar-amp simulator. You get the idea. It's worth noting here that the Chameleon is neither a PC in a box nor a VST plug-in engine. Chameleon Soundskins are codes specifically optimized and dedicated to the unit's hardware.

The heart of the Chameleon is a 24-bit 100MHz Motorola DSP56303, the same DSP found in many of the effects units and virtual analog synths on the market today. Because Soundskins are optimized for this DSP, are born to process sound and are not word processors, the Chameleon boasts a 24-bit A/D conversion at 48 kHz, 256× oversampling, with a 0.6ms delay from input to output. That's right, no latency issues. In addition to the chip itself, Soundart has included four “mega-words” of 24-bit RAM, allowing mono delay times of longer than 87 seconds. Air-tight microcontroller duties are handled by the Motorola ColdFire chip, and Soundart even resurrected the classic MIDI engine from the Atari ST to give the Chameleon the tightest MIDI timing possible.

What struck me first when opening the shipping carton was Chameleon's simplicity in design. Although the front panel may look like that of any other synthesizer or effects unit, upon closer inspection, you discover the intended universal nature of the four generically labeled master control buttons, eight edit-parameter buttons, three real-time control soft knobs and a large rotary encoder dial. Your window into this universal world is a green backlit 16×2-character LCD.

Around back, you'll find a stereo pair of ¼-inch analog outputs, another pair of ¼-inch analog inputs and an RS-232 interface port for use by Soundskin developers. A stereo ¼-inch headphone jack is located on the front panel. Considering that the unit uses a 24-bit DSP, it's rather odd that it lacks digital I/O of any kind. I'm pleased to announce, however, that the overall build quality of the unit is extremely good and feels rugged enough to endure the rigors of studio or stage. Fortunately, the build quality isn't the only thing that impressed me. This reptile is superbly clean and quiet and rarely messes its cage. The quality of the sound path is constant from input to output, with low noise and signal coloration throughout.


Chameleon ships from the factory preloaded with the company's flagship Soundskin, Australis, an analog-modeled polysynth. Typically, I'd dive right in and start playing with a new toy that just arrived at my studio, but in this particular case, Chameleon's “reskinability” got the better of me. I quickly logged on to the Soundart Website, downloaded all eight currently available Soundskins (including Australis, because once you overwrite it with a new skin, it's gone, so you'll need it on disk to reload later) and proceeded to try my first application load.

Soundskins are stored inside the Chameleon on nonvolatile Flash memory. Loading a new Soundskin is as simple as playing back a MIDI SysEx file. A typical soundskin is around 200 KB in size, yielding a transfer time of just longer than a minute. Although the largest file took nearly seven minutes to transfer, I was able to reduce this time by jacking up the playback tempo of my sequencer. Once loaded, a skin is there to stay, even through power-downs, until the next reskinning. Note: Only one Soundskin can reside in the unit at a time. Incidentally, all Soundskins come with well-written manuals in PDF format, including helpful appendices and MIDI-implementation charts.


With a test transfer under my belt, I reloaded the Australis analog polysynth and gave it a whirl. As with computer plug-ins or modeled hardware synths, the Chameleon sounds only as good as the code upon which its Soundskins are written. Australis, for one, did not let me down, becoming a luscious 16-voice, eight-part multitimbral analog-modeling synthesizer. The synth is perfect for creating everything from pads, leads and basses to percussion and wild sound effects. Specs are pretty standard fare: two multiwave oscillators and one sub per voice, colored noise and ring modulator, variable PWM, oscillator sync, frequency modulation and unison mode. Sound coloring is courtesy of two resonant analoglike multimode filters per voice, configurable in 12dB/octave and 24dB/octave slopes. Two ADSR envelopes are included, as well as two multiwave LFOs; a flexible mod matrix; a programmable arpeggiator; comprehensive MIDI sync; and ample multi-effects per part, including a global delay.

Gorgeous strings and dreamy film pads abound in the 384 factory presets, and all display little or no aliasing at the top end. The filters, although not groundbreakingly cool, do sound great, and you should have no trouble at all coming up with a sound to fit just about any job. PolySynth, a bang-on attack of '80s richness, proves this. The basses were some of my favorites during audition. Patches such as Allusion and Smudgy cast an unearthly warmth throughout my studio, and TransGen, a perky sound with deep resonance and panned delays, proved ideal as a fun supporting bass to just about any electronic style. Searing leads, cool bells, Fairlight-esque glass pads, Oberheim-like synth brass and organs, and special effects and transitions ranging from beautiful to bewildering round out the pack. Even some deft analog percussion is thrown in for good measure.

With my excitement piqued, I proceeded to load in Fahrenheit, the Chameleon Dance Music Module application. This acid monster comprises six different but interconnected modules: two identical TB-303 emulations; a TR-808; a TR-909; an advanced channel mixer for adjusting level, pan and aux sends for each TB and TR voice or that of the stereo inputs; and effects, which include simple and complex delays, four distortion units, four compressors, one resonant filter effect and a global reverb. Without gushing, this skin is uncannily accurate. Right down to self-imposed filter-cutoff limitations found on the original equipment. At first, I was upset that the TB-303 couldn't be completely squelched out down to 0 Hz, for instance. Soundart, however, chose to make a completely faithful copy of the original, which only filters down into the low hundreds of Hz. Likewise, it only opens up to a peak of around 8 kHz. Onward, I came across another true gem in the MonoWave II Soundskin, a fat and dirty monosynth based upon creator Paul Maddox's respected Modulus Electronics MonoWave hardware synth. The history on this funky little beast is scattered all over the Web, but in a nutshell, MonoWave II is a digital-analog hybrid model using a three-oscillator structure pulling from 256 waveforms; an LFO; three ADSRs; and a 4-pole 24dB resonating filter with the unique option to seamlessly “sweep” between 4-pole Moog ladder-style, bandpass and 1-pole modes for those “fizzy” sounds. A detailed mod matrix and a contrastingly simple delay-effects section really make this synth dance and sing. The mere 20 presets set you on due course with absolute winners, such as the enormous Big Sweep and authentic Bob's Sweep. You could clean out your ears with the crystalline presence of PPG Bell.

Without space to explore each synth Soundskin in depth, I can say this much: They all offer features on or well above par with the rest of the VA competition out there and are relatively easy to program. High marks are deserved all around.


The remaining five Soundskins available at the time of this review fall into the traditional DSP effects category. Chromasonic is the Chameleon's flagship multi-effects processor and is really three separate mono effects units linked together in a chain. Offering up meat-and-potato algorithms such as delay, chorus, flange, reverb, wah and dynamics, it does the trick and sounds good, but it's nothing new. I can't see tying up the Chameleon in the studio for it alone.

The FX Designer by 3-D effects expert SpinAudio is a different story, however. The main idea behind this Soundskin is to provide an easy way to create various delay-based effects from their basic building blocks: comb and allpass filters. For example, it's possible to make a reverb that sounds like a room whose size warps through time in physically impossible ways. To create that sort of twisted dementia, FX Designer offers six modulated delay lines with comb/allpass mode switching, six assignable LFOs and a flexible tap-signal router that interconnects taps into a complex network. Despite the skin's complexity, asigning the real-time soft-knob assignments was a simple process of holding down the shift key and turning the desired knob while the parameter is displayed in the edit mode. But if you don't feel like digging through menus, the presets, thankfully, rock.

Also from SpinAudio comes the new Roomverb M1 version 1.0 skin, a true-stereo studio-quality reverb based on the company's Virtual Room Acoustic modeling techniques. From phone booths to massive halls, highlight provisions include 20-second-long silky-smooth tails; frequency-dependent decay control; separate output equalizers for early and late reflections; reverb-tail modulation; and inputs configurable as stereo, split L/R or dual. The 100 factory presets are wonderfully crafted works of art that rival processes costing thousands. I would not hesitate for a minute to call this my main studio reverb.

Infiltrator is the Chameleon's funky vocoder and filter-bank skin. A highly creative sound-shaping tool that is essentially based on two banks of powerful 24-channel filters, it was principally designed as a powerful vocoder but has since evolved into a much more powerful filtering-effects and DJ tool. I was blown away by the freakiness that this application can generate. Deep editing is not for the weak of heart, though — it's a little bit like rocket science. Fortunately, the real-time controls have been assigned wisely by the programmers and bring much of the important parameter twiddling to the front panel. Presets include lots of typical robotic and MIDI-keyable pitched vocoders, but there are also some really cool filter, delay, EQ and signal-analysis tool-kit gems hidden in there.

Rounding out the pack is the newly released Amp-O-Matic guitar-gear-emulation Soundskin. It gives you 16 preamplifier models (tube and solid-state), three equalization models (vintage, modern and parametric), four power-amplifier models and 15 speaker-cabinet models. On top of this, there are two monophonic pedal-style effects before the amp and three independent stereo effects after the amp. Real-time control knobs are assignable to six groups of three for plenty of twiddling freedom. As far as sound goes, not only did I grow to greatly admire the quality of the preamp, EQ, amp and cab models individually, but the presets themselves deserve a firm round of applause.


Theoretically, Chameleon could sound just like anything else on the market. Thankfully, Soundart has chosen to carve its own niche by bringing applications that are designed to be just a little left-of-center to this platform. In addition, Soundart's commitment to keeping the platform 100 percent open-source and offering Soundskins for free is what makes the Chameleon so special.

Sure, I have a few quibbles here and there. Waiting for Soundskins to load by MIDI dragged me down. Likewise, I found the inconsistency in GUIs between Soundskins to be a little hampering to the unit's operation. It would be nice if developers could adapt to a standard whereby skins conform to certain button assignments for common tasks such as effect bypass and undo edit. I also found the large data encoder's placement to be in the way during edits in which your fingers have to jump between parameter buttons and the real-time soft knobs. The lightest tap of the dial would send the program flying, losing your edit.

My immediate wish list includes the addition of USB and digital I/O. I'd also love Soundart to come out with a second-generation Chameleon with multiple DSPs so that you can use more than one skin at a time. Also, larger Flash RAM would be welcome so that you can have many Soundskins resident in the unit at once. User-installable sample RAM that would allow for sampling and loop-processing skins to be created would also be a huge bonus.

The Chameleon does not pretend to compete with the dominant trend in today's studio world. Instead, it complements it. With the low price and the growing selection of Soundskins, I can't think of any single box of greater value on the market today.

Product Summary





Pros: Superbly clean. Creatively coded Soundskins. User-updatable and programmable. Air-tight response. Excellent MIDI spec based on Atari ST interface. Priced right.

Cons: Current UI structure not intuitive. Loading Soundskins can be slow. No digital I/O. Only available in North America direct from manufacturer.

Contact: tel. 34-93-419-5269; e-mail; Web