Remix reviews the Radikal Technologies Spectralis hybrid synthesizer/sequencer/filter bank. This review includes hardware specifications, lists and descriptions of features and company contact information.

Since its debut nearly three years ago, Spectralis' life cycle has been an interesting one. Developer Jörg Schaaf didn't wait until integrating every last ounce of his vision into the dream machine; instead, he launched Spectralis using prerelease versioning and added features on its way up to v.1.0. Some users jokingly refer to this ploy as the “five-year beta test.” But suffice it to say, the code is solid, and Spectralis is certainly no beta machine.

The recent major update, called Spectralis Xtreme Update 097, adds many exciting new features to this hefty groove-oriented tabletop unit. Part hybrid synthesizer, pattern-based step sequencer, beat matrix, fixed filterbank, sampler and expandable DSP engine and built like a tank, Spectralis is a no-compromise modular instrument that combines rugged live usability and tactile immediacy with the best of both digital and analog sensibilities. While the Xtreme Update 097 focuses on the already-addictive live-performance potential of this beast, it is the whole — not the sum of its parts — that's now the synth's strongest attraction.


The increasingly more powerful Hybridsynth module now consists of four free-running, analog-modeled oscillators (of continuously variable waveshape) that can be independently routed through pitch and volume envelopes and various filter combinations. An analog 24 dB/octave lowpass filter and a 12 dB/octave multimode lowpass/highpass/bandpass/notch filter are capable of self-oscillation. What's really cool is that the filters can be modulated in the audible frequency range by the oscillator section and can operate in series, parallel or as layers to create new filter-curve varieties. Scrolling the 26 pages of oscillator parameters on the 2-line LCD gives some indication to the cavernous depth of flexibility in sound design. No less than 10 LFOs are at your disposal in the Hybridsynth section alone.

In contrast to most “grooveboxes,” Spectralis offers true 32 stereo-note multisampling integrally tied to the powerful subtractive-synthesis capabilities of the Hybridsynth. This DSP-based section provides not only three discrete polyphonic digital synths (called DSynths) to the step sequencers, but also a necessary foundation of 32 stereo drum samples. You can load AIFF, WAV and Soundfont2 multisample instruments with the included PC-only Sample Conversion Utility software. The DSP section also powers Spectralis' dual stereo-effects processors.

A fixed filterbank consisting of one lowpass, one highpass and eight bandpass filters is sprawled across the lower portion of the panel with abilities for sequence-controlled level modulation, Q and slope control and frequency-band panning.

Spectralis includes a multi-engine sequencer with a 16-button programming matrix and 32 tracks (doubled from old versions) for step sequencing, six tracks for real-time recording and an 11-part drum grid. Each sequencer line may now be as many as 192 steps in length and have separate settings for direction, length and resolution (drumgrid tracks can have 16 bars with 192 steps per bar). Moreover, single steps in each stepsequencer line can be muted, skipped or set up with an adjustable glide. Deeper still, you may incorporate additional attack, decay, square and soft-curved envelopes with beat-oriented duration and individual depth control at each step. Internal song memory stores as many as 32 songs and 1,024 patterns.

This sturdy, 8 lb. steel-and-wood wedge has front-panel control aplenty, with 46 buttons and 37 endless rotary encoders that double as push buttons. Around back are eight ¼-inch outputs (Main L/R, Direct 1-4 and Hybridsynth Direct Out L/R) and two ¼-inch inputs for feeding signals into the filters and/or filter bank (external sampling may be added later).

A USB 2.0 port allows Spectralis to exchange program data, transfer samples and update the firmware with a PC or Mac. Generic USB drivers are integrated, eliminating the need for proprietary drivers on your computer. When connected, drive icons appear on your computer's desktop. Seeing as the Spectralis boots from internal flash memory (64 MB resident memory) by default, your live sets — including samples — are always there, and the USB connection makes it convenient to offload, manage and recall/rewrite the cache with new content prior to a gig. Samples, sounds, patterns and songs may also be stored with two SmartMedia cards slots on the far right of the front panel. Establishing a USB connection is only necessary to copy data and really bears no fruit during normal operation. Spectralis does not stream audio over USB, and no official software editor exists at this time.


What's always made Spectralis special has been its completely open, freely assignable modular design that encompasses the discrete components and makes them feel as one. For example, you can process samples in the digital section through their own multimode filters or route them over to the analog filters, the fixed filterbank or all of those, as well as feed them back into themselves in almost unlimited fashion. Alternatively, you might adjust the levels at each stage to blend with the signals coming in from the external inputs acting as envelope or timbral sources. True perversion, however, comes from tapping into the exotic range of modulations in the analog-oscillator section (including Time Linearity Modulation, Audio Range FM, Oscillators Sync and Bit Reduction) and assigning them to control various parameters of the digital synth or fixed filter bank. Madness!

This version also adds “trigger group” support to the engine, so oscillators, filters and the noise source can be assigned to independent trigger groups, which are in essence subparts to the sequencer. For example, I built a trigger group to which I assigned analog oscillators 1 and 2 and the 24 dB lowpass filter; sequencer events assigned to this trigger group will send pitch and velocity information to its elements exclusively. Next, I built a second subpart by feeding oscillators 3 and 4 into the multimode filter and assigning these three sound-engine elements to a second trigger group. By then assigning the noise generator and filter bank to a third trigger group, I realized that the Hybridsynth could essentially sport three independent monophonic synths in one. Used cleverly, the fixed filterbank can perform the most incredible textural or vocoded noise rhythms, leaving the four main oscillators to do their thing separately. And that's only one cool example. You can build any other kind of combination, with the settings saved as a new preset or memorized as part of a pattern.

Mucking around with all of Spectralis' aforementioned features in real time is a joy. With the on-the-fly freedom to add or remove parts, rearrange sequences, selectively tweak drum sounds and process external audio through the filter bank (resampling all that into the DSP section may be added later), Spectralis is a blast for live editing and remixing. The pick-and-choose modular interface provides an outstanding level of interactivity, with recording and live performance melding as one continuous, musically coherent process.

One of the best additions in the Xtreme Update 097 is the ability of the step sequencer, or any modular part of the Spectralis for that matter, to trigger and control external MIDI and software instruments. That means you can now supplement the drum editor with externally connected sound sources, for example, and leave your laptop at home, using the Spectralis as a hardware sequencer. Though it receives MIDI Clock, the Spectralis cannot send it for synchronizing external sequencers/grooveboxes. Schaaf says he's working on incorporating that into future firmware. He also mentioned that future updates will add groove quantize, real-time recording of all knobs and MIDI controllers into the sequencer, REX file support with special sequencing modes for REX files and more.

The Spectralis suits any style of electronic music, though I found it sounded sweetest at the “Xtreme” end of the spectrum. The aggressive analog synth and self-oscillating filters totally kicked ass doing thick and heavy hard-house, blistering techno and acid, while twisted patterns and filtered percolations from the digital synths made for beautiful IDM and minimalist arrangements. The included samples provide a great starting point to learn by, but you'll definitely want to import more of your own. Likewise, you'll want to replace or edit the excellent built-in songs and patterns as you learn the sequencing facilities. Included material runs the gamut from electro, trance and trip-hop to jungle, drum 'n' bass, experimental pop and more.


There's never a dull moment with Spectralis, and inspiration comes simply by flipping on the power switch. Its modular nature and flexibility simply begets creativity. Depending on the complexity of your live set, Spectralis can even hold down a gig with little else required. However, the coup de grâce is the ability to tweak and trigger external synths and samplers from the front-panel controls, while being tethered step for step to the internal sequencer in a fluid and homogenous manner.

It may look like a groovebox, but Spectralis is a full-blown music-making machine. With all the novelties of modern production ensconced by the sensibilities of classic drum machines, retro sequencers and analog synths, Spectralis is the kind of do-it-all instrument for which you can afford to scale down your entire studio. Or, maybe it's the kind of synth for which you'll have to scale down your studio to afford! Either way, it's nice to see this contribute to the recent renaissance of exciting hardware synths. The Spectralis has carved its own niche as a superior product with a unique style.


Pros: Balls-to-the-wall sound. Fat analog-modeledsynthesis and two true-analog filters. Edgy-sounding digital synthesis and inventive fixed filter-bank routing. Highly interactive with flexible mapping of controllers to external MIDI devices. Open-ended architecture and updatable firmware. Robust build.

Cons: Pricey. No digital I/O. MIDI Clock send not supported. No software editor.