The Korg RADIAS was launched in 2006 for £999 and was one of Korg’s most advanced synthesiser at the time. The RADIAS is powered by Korg’s Multi Modelling Technology, which features analogue modelling, PCM waveforms, VPM (Korg’s version of FM), drum kits, arpeggiators, dual step sequencers, virtual patches and a vocoder. Of all the recent look backs at some of my old music tech, this is one of the most complicated! The RADIAS is a rack mountable synth that also has the option of a keyboard and rack frame that the module can fit in. The module can be flat or raised up, with a blanking plate positioned on the left or the right. I have my Minilogue sat on it, back in the day it would be your chunky laptop!

UPDATE: I have made my Korg RADIAS sound bank available for free download


There is full sized midi (In/Out/Through), USB Midi, stereo outputs, audio inputs with level switch, a vast array of knobs and a 128×64 LCD display. The USB interface is used for the librarian / editor software (Windows or Mac, and it seems to still work in 2023), and you can use it to route midi output from the DAW, so you can send midi to the internal sound engine or to a synth connected to the midi output of the RADIAS. I use this for my TX7 and I use the RADIAS keyboard to play the TX7.

Synth Engine

Essentially, the RADIAS is a four-part, dual oscillator virtual analogue with hands on controls for most of the sound controls. You can layer or split sounds and one of the parts can be dedicated to drum kits. The analogue model is the familiar subtractive synthesis design with dual oscillators, dual filters, dual LFOs and dual ADSR envelopes. Oscillator 1 has saw, square, triangle and sine waves, and there are 64 digital waves (very much like the MS2000) with electric piano and bell type sounds. Two modulation controls can change things like pulse width, and there is a unison mode, cross modulation, FM and ring mod. Oscillator 2 is a little more basic with the standard analogue waves which you can sync with Oscillator 1. There are two filters, filter 1 is a continuous variable multi-mode type with 24db, 12db low pass options as well as high pass and band pass. You can have the two filters run in series, parallel or individual modes. Filter 2 has a switch rather than a continuous sweep type but there is a comb filter. The filter has a dedicated ADSR. The amplifier has a dedicated ADSR envelope and a drive option. There are two LFOs and 6 virtual patching options.


There is a 16 band vocoder with format motion, which means you can record phrases with it (up to 7.5 seconds). The vocoder sounds great, and it came with a headset microphone which I still use with the vocoder.


There are 128 drums sounds which includes TR808 and TR909 sounds as well as 80s style Simmons kits, Korg ER1 and modular type sounds.

Arpeggiator and step sequencer

There is an arpeggiator which you can assign to any of the four voices and two step sequencers which are great for drum patterns. There are also two 16 step mod sequencers which can affect any of the synth parameters.

Two Insert and One Master Effects

Each part can have two insert effects plus EQ plus a single Master effect for the performance. There are flangers, choruses, phasers, delays, and reverbs. Some effects, like the Rotary Speaker effect, use insert one and two.


I found the RADIAS presets to be a bit much to put into a track but once you spend some time with it and pare back the performances, the sounds can still be very usable. The drums are particularly good, and you can get some great digital sounds out of it. While making the demo track I found it difficult to get sounds I wanted to fit into the mix which is probably use this less than many other of my devices, apart from using it as a keyboard controller for my TX7. It’s a good synth, maybe a bit dated now but with a bit of work it is still very usable. I don’t use the vocoder much but it’s great to put on the headset every now and then!


In this video I go through some of the presets and sounds I have built up over the years, I demonstrate the architecture of the synth engine and look at the librarian software.

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