While other manufacturers seem to be caught up in repackaging yesterday's news, Korg has made huge inroads with its cutting-edge Multi Modeling Technology

While other manufacturers seem to be caught up in repackaging yesterday's news, Korg has made huge inroads with its cutting-edge Multi Modeling Technology (MMT) of late. Though first implemented a number of years ago in the Electribe series, the Radias really propells this multisynthesis technology into the spotlight. The 24-note polyphonic Radias also borrows some of the finer points from last year's wallet-wilting Oasys megasynth, including its heralded low-aliasing oscillators and zipper-free filters, but also brings forth new ideas in the oscillator, filter and amp sections — including formant waveforms, a new comb filter and wave-shaping functionality — as well as a wild new formant-motion vocoding feature, all at a price that's almost as attractive as its custom-configurable design.


When the box arrived, I thought Korg may have entered the beer keg or minifridge business. The size of the Radias shipping carton was enormous. It turns out that the Radias consists of a 4U rackmountable sound module (Radias-R) and a dedicated keyboard assembly (RD-KB), each of which come packaged in a retail-ready box within a larger box, although Korg does not intend to sell them separately. Inside sat lots of other bagged goodies, including screws, nylon washers and bushings and a deceptively-hidden disposable screwdriver that proved crucial for assembling this beast.

Initially quite peculiar looking, and a definite departure from Korg's typical workstation aesthetics, the RD-KB is a 49-note keyboard ensconced by a large rectangular framework of 1-by-1-inch square-extrusion tubing that extends out about half a foot behind the keyboard for carrying and structural support of the module. As though taking a modern-day page from the Minimoog book of design, the keyboard features a unique hinged mounting-rail system that allows the 19-inch wide Radias-R to pivot up or down and position anywhere along the 35-inch keyboard's span. It may look the most retro when centered, but sliding the module fully over to one side (left or right) makes popping in the included 12-by-7-inch accessory tray possible, which is ideal for placing a laptop computer, Electribe, Kaoss Pad, DAW control surface, mouse pad/trackball or other gadget comfortably (and ambidextrously) within hand's reach.

The module also functions as a stand-alone tabletop synth or in a standard rack, though you'd need to leave extra space in a rack for plug and cable access. Audio connectivity includes ¼-inch stereo main and a pair of individual outputs, dual ¼-inch inputs switchable between Mic/Line input levels, and a dedicated mini-stereo jack for the included condenser microphone headset in vocoder mode. Also provided are MIDI In/Out/Thru, USB, assignable pedal and switch inputs and a large, 4-pin power jack to accept the proprietary line-lump power-supply cable included.

Both the module and keyboard look very stylish in their silver-fleck finish and seem built for the long haul. Mounting the module to the keyboard was simple and straightforward, taking no more than 10 minutes when reading every fine line in the assembly guide.

For those who are thinking it would be cool to use the RD-KB keyboard to control another synth module — not so fast! True, you could fit any 19-inch, 4U rack synth onto its rails, but the keyboard itself doesn't come with MIDI ports or even its own power supply. Instead, it uses a proprietary 9-pin cable that connects directly to the Radias module like an umbilical cord, carrying note and knob information and power down one pipe; thus, Korg's decision not to sell the keyboard separately. On the other hand, the RD-KB offers a Velocity-sensing keyboard with traditional pitch and mod wheels, but no Aftertouch or alternative forms of modulation or control, so its strengths as a stand-alone controller would be limited anyway.

The synth comes with Radias Sound Editor software and a USB MIDI driver for Windows XP and Mac OS X. Clearly laid out with powerful librarian facilities, you can edit, save, store and manage all Radias settings using a USB connection for quick and easy data transfers. At present, you can't stream the Radias audio output directly to a computer or use it as a plug-in (à la the Access Virus TI). Time will tell if Korg will add that feature.


The Radias front panel is packed with knobs and buttons that at first may seem overwhelming — nothing a few sessions of getting acquainted won't cure. The upside is there's no shortage of parameters to control in real time. There are 63 backlit buttons that glow red when activated, including a bank of 16 larger buttons across the bottom, appropriately called the 16Keys bank. The knobs may be a bit too closely spaced; more than once I knocked an adjacent parameter accidentally, though working with the module in its upright locked position is much easier than when flat.

The 128-by-64 white-on-black backlit LCD is easy to read, and though its small size would be considered limiting on any other synth this complex, Korg's cool auto-parameter system combines with large fonts that make the display a snap to read quickly, especially at a dark gig. For instance, by tapping each of the 16Keys' soft-buttons, you're taken to its respectively labeled page view (such as Common, Oscillator/Mixer, Filter, Amp, EG and so on). In Edit mode, adjusting any knob or button instantly directs you to the appropriate parameter page, so you can see the value changes as they occur. Though the bright yellow lights glowing behind the knobs look cool, they don't indicate values and serve no practical purpose other than knob location in the dark.


Departing from Korg's usual scheme, the Radias doesn't use Multis or Combis but rather good old-fashioned patch Programs, of which there are 256 user-editable locations. Each program is composed of as many as four timbres, which can be split, layered, zoned to a specific range of keys or individually played by the arpeggiator or one of the step sequencers. Additionally, each timbre can be assigned to a specific MIDI channel for four-part multitimbral operation. A wonderful aspect of having timbres embedded within programs is that you never have to worry about altering or destroying another patch's sound inadvertently. To speed up the sound-creation processing, Radias includes 128 handy programming templates each for programs, insert effects and master effects. You can also save your own sounds or effects settings as template data for future use.

Each timbre provides two oscillators that share the low-aliasing design of the Oasys and a noise generator. Oscillator 1 can be set to one of nine algorithms, including conventional analog synthesizer waveforms, 64 digital synthesizer PCM waveforms, drum samples, formant waves, noise or an external audio signal. The second oscillator offers only four wave shapes: sine, triangle, square and sawtooth. An analog tune feature lets you control the amount of simulated oscillator drift, and five portamento curves allow detailed control over glissando passages and gliding between notes. Modulation such as X-mod, unison and Variable Phase Modulation (a simplified form of FM synthesis) can be applied to the analog waveforms of Oscillator 1, while Oscillator 2 can modulate Sync, Ring or Ring Sync.

One timbre per program can be assigned to a drum kit containing 16 PCM waveforms. There are 24 factory drum kits (32 memory locations total): acoustic, future jazz, trance, 808 and 909, deep and hard-house, electro, hip-hop, garage, R&B, downtempo, drum 'n' bass, Nu Breaks, glitch and other IDM-oriented kits. There are 128 drum PCM sounds, including some eclectic sources such as vocal percussion borrowed from the Korg Wavestation.

Per timbre, there are three ADSR envelopes, two LFOs, three modulation sequencers and six Virtual Patch matrices, which allow 15 modulation sources to be routed to any of 15 parameters. External audio can act as a source. This is extremely powerful stuff.

Radias is blessed with incredible sounding multimode filters — two per timbre, configurable in series, parallel or direct (Osc 1 to F1; Osc 2 to F2). The modes include 24dB/octave and 12dB/octave lowpass, highpass, bandpass and comb. Filter 1 has the distinction of being able to sweep through each type in continuously variable fashion, which is particularly cool for warped sounds. Even with resonance boosted, you'd be challenged to hear any unmusical stepping from these filters. A timbre's final amp stage features the ability to add either Drive for a warmed up tone, or Waveshaper, with options for lowering the sampling rate, waveform limiting and distortion, suboscillator content and more.


The jewel in the crown for many will be the highly sophisticated, sweet-sounding Radias vocoder. With 16 adjustable frequency bands, it is capable of much more than traditional robotic effects. In fact, this vocoder may be the most intelligible and musical I've ever heard, not to mention the easiest to set up, program and use. When entering vocoder mode, more than half of the front-panel controls become dedicated to vocoder parameters, and individual level and pan settings for each vocoder band can be manually tuned using the row of knobs just above the 16Keys. Using the extremely sensitive headset mic, I achieved immediate and wonderfully accurate results; some of the best came from mere lip movements and whispers when tweaking parameters for input gate sensitivity and threshold, filter envelope follower sensitivity, synthesis filter formant shift, carrier filter cutoff frequency and resonance.

The coolest, however, is Korg's new Formant Motion function, which uses filter banks to analyze any input signal and records that as formant motion data. You can save and retrieve as many as 16 formant motion recordings in the internal memory — each as long as 7.5 seconds in length — and play them back at any time for complex moving vocoder programs that don't require a mic input. Using the editor software, you can offload and import motion data.

Two insert effects and dual-band EQ are available for each timbre, in addition to a program-wide master effect (no individual send levels per timbre). The 30 effects types run the gamut, including tape, line, tap and mod delays; stereo reverb, chorus, phase, flange, filter and wah; compressor; limiter; distortion; decimator; tube, cabinet and rotary speaker simulator; and complete oddballs like talking modulator, stereo ring mod and grain shifter. Any effect parameter can be assigned to the front panel knobs for instant control.


The Radias features dual 32-step, analog-style sequencers that can generate two independent tracks or chain together to form a single, lengthy 64-note sequence. Those allow you to record simple patterns or phrases such as a bass line and a drum groove, and assign two timbres within a program to play those parts while you play the remaining timbres from the keyboard. You can perform step entry via the keyboard or the 16Keys and edit the duration, velocity and note number for each step. Each sequence can be of a different length and in any of the three playback modes (OneShot, Loop, Step), allowing potential for all sorts of crazy, messed up polyrhythmic evolution on each new pass.

Just as step sequencers change oscillator pitch over time, the modulation sequencers provide changes in modulation data of individual timbres over time — similar to classic analog modular synths with integrated sequencers. Each of the three mod sequencers per timbre can modulate any of 41 continuously controllable parameters and be recorded in step time using the 16Knobs or in real time using the Motion Record function. Mod sequences can be a maximum 16 steps (and the length applies to all three mod sequencers per timbre) and can run as a one-shot or a loop in forward, reverse or alternating directions. Each step can be sent as a hard-jump value or as a continuous morph between steps. I haven't had this kind of fun since using the parameter-lock features on the Elektron Monomachine sequencer and the 4-track multistep modulator on the Roland's V-Synth XT, both of which the Radias trumps in depth.

The arpeggiator offers the familiar choice of up, down, alternating, random or triggered chord steps. The resolution, key window, swing and octave range can be set per program. The 16Keys can set each step's gate time, velocity, tie and off status, allowing you to create a broad range of melodic and rhythmic patterns. As with the step and mod sequencers, tempo is always adjustable from a dedicated front-panel knob or by tapping.


Loving the Radias is easy ‘cause it's beautiful. It's a nice change from the routine workstation vibe for Korg; you can't help but be inspired and have fun with this thing from the moment you lay eyes and hands on it. Korg succeeded in incorporating a bit of soul from its hallmark synth lines over the years. The aggressive sounding MS-20 and fat PolySix analogs, digital M1 through Triton workstations, dynamic Wavestation, interactive Electribes and the panache for modern vocoding simplicity of the microKorg are all represented.

Every note of every factory program sounds completely awesome, many even breathtaking, full of presence, personality and shimmering high-end detail. The multimode oscillators sound truly gorgeous, and the modern filter design leaves no stones unturned for the adventurous sound designer. The Radias will likely be coined a trance lover's synth for its one-note anthems, inherently silky sound quality, effortless percolating rhythms, bright open treble and tight punchy basses. Granted, it's certainly not as dark and gritty as it could be for harder-edge purposes — not even after applying degenerative effects and filters. However, there's nothing wrong with being nice and clean. In fact, one of the reasons I like it so much is that Radias simply plays well with others in a mix. And with performers leveraging the Radias' innovative sequencing and performance features live onstage, Korg has a multifaceted winner on its hands.

RADIAS > $1,999


Pros: Exhilarating sound. Advanced multisynthesis architecture. Performance-based step and mod sequencing. Low-aliasing oscillators and continuously variable filter types. Formant motion recording. Easy to use and intelligible vocoder. Bold and innovative design.

Cons: Maximum 24 notes polyphony. Maximum 4-part multitimbral operation. Keyboard assembly slim on control features and cannot be used on its own as a MIDI device. No digital output.


(for the librarian software)

Mac: G4/400 MHz; 256 MB RAM; Mac OS 10.2.8 or later.

PC: Pentium or Celeron/500 MHz; 256 MB RAM; Window XP Home/Professional SP 1 or later.