The Korg EXB-MOSS synthesizer: a hidden gem of physical modelling

In 1999, Korg launched the OASYS PCI card for PC and Mac. It was a multi-synthesis engine that included sampling, FM and physical modelling. The high price ($2000 in 1999) meant only 2000 cards were sold and the project was cancelled.

UPDATE: Part 2 is live, looking at the KARMA features

However, the technology made its way to other products, including the Z1 physical modelling synth. Its technology then was brought down to an expansion card for the Korg Triton and Karma workstations.

The Korg EXB-MOSS (Multi-Oscillator Synthesis System) board fits inside the Triton or Karama and adds a new Bank F to the synth with 128 new programs. MOSS has PCM, analog, VPM (variable phase modulation) and physical modelling.

The 12 oscillator types are:

• Standard
• Ring Modulation
• Cross Modulation
• Sync
• VPM
• Comb filter
• Resonance
• Organ model
• Electric piano model
• Brass model
• Reed model
• Plucked string model
• Bowed string model

Where this system excels over samples is that you have full control over the way the sounds are made. For example, the brass model enables you to model the physical characteristics of the instrument, including things like the bell shape. On a guitar, it models the pickup location, pluck strength and other parameters. This gives you a full range of expressions for each sound using velocity, aftertouch and real time controls (CC) so you have as much control of the sounds, just like you do with a physical instrument. So, you end up with rich and expressive sounds, but it does mean programming isn’t as simple as subtractive synthesis or using samples.

With massive gigabytes of multi-samples available now, physical modelling seems to have fallen by the wayside. But as with all music technology, the tech comes back around eventually when it becomes “vintage”.

As you can hear in the demo video, there are some great FM type sounds, expressive guitars, organs, brass and bowed sounds which all have a full range of dynamics.

In this video I give a brief overview of Korg MOSS and demonstrate how the synth engine works with various sound demos. If you want to jump to sound demos only without any talking, go to this part of the video: