Korg Opsix MkII Altered FM Synthesizer

The Korg Opsix MkII is a 37-key FM synthesizer with 64-voice polyphony, double the original Opsix. Its six-operator architecture goes beyond traditional FM synthesis with multiple operator modes (FM, ring modulation, filter, wavefolder, and more), giving it a wider tonal range than conventional FM synths. The operator mixer provides hands-on control of all six operators simultaneously, making FM sound design visual and immediate.

Altered FM Synthesis

Six operators with 42 algorithm configurations. Each operator can function as a standard FM oscillator, but also switch to ring modulation, filter, wavefolder, or effects modes. This "Altered FM" approach lets you create sounds that range from classic DX-style electric pianos and bells to aggressive industrial textures and evolving pads that pure FM cannot achieve.

Interface & Controls

Dedicated ratio knobs and level sliders for all six operators provide tactile, real-time control. Six data entry knobs edit deeper parameters. A step sequencer records up to 16 steps with 6 notes per step, and a motion sequencer captures up to 6 lanes of knob automation. The arpeggiator offers 7 patterns.

Effects

29 effect types across multiple categories: chorus, phaser, flanger, rotary speaker, distortion, guitar amp, compressor, delay, reverb, shimmer reverb, and more.

Specifications

• Keys: 37 full-size, velocity and release-velocity sensitive
• Sound Engine: Altered FM (6 operators)
• Polyphony: 64 voices
• Programs: 500 (250 preset + 250 user)
• Favorites: 64 (16 slots x 4 banks)
• Effects: 29 types (modulation, delay, reverb, dynamics, EQ)
• Sequencer: 16-step with 6 notes/step, 6-lane motion sequencer
• Arpeggiator: 7 patterns
• Connections: L/Mono and R outputs (1/4" TRS balanced), Headphones (1/4"), Damper (1/4"), MIDI In/Out, USB Type B
• Power: AC adapter (DC 12V, included)
• Dimensions: 565 x 338 x 90 mm (22.24 x 13.31 x 3.54 in)
• Weight: 2.9 kg / 6.93 lbs

In the Box

• Korg Opsix MkII
• AC adapter (DC 12V)