Multi/Poly is an iconic model of a poly-analog synthesizer inspired by the Korg Mono/Poly, offering a vast range of sounds from a lush analog soundscape to the flexibility and versatility of the digital world. Multi/Poly combines rich tones familiar from modular synthesizers with experimentation and customization: the synthesizer bends towards the modular traditions of the US East and West Coasts, while the digital side allows for the use of wavetable oscillators and new filter models to shape soundscapes.

Multi/Poly features new filter and oscillator models: each voice has its own virtual circuit, where oscillators, filters, envelopes, LFOs, and portamento circuits model different analog circuits. As a result, each virtual circuit has a slightly different character, creating richly textured tones. The variability of sound can be adjusted on a per-sound basis, allowing for greater or lesser expansiveness according to personal preference. Multi/Poly takes a step deeper by also modeling the behavior of different analog synthesizer circuits such as envelopes, portamento, and VCA circuits.

The synthesizer has four oscillators per patch, each of which can be of classic, digital, or waveshaper type, enabling access to traditional synthesis, modern wavetable synthesis, and West Coast waveshaping synthesis, where a simple wave is modulated by a wave shaper. The instrument features five different 4-pole filters, as well as a comprehensive collection of linear 2-pole and 4-pole filters, alongside Korg's own Multi Filter.