Overview
The opsix is Korg’s Altered FM synthesizer. It starts from classic six-operator FM and adds new waveforms, filters, shaping, effects, LFOs, and envelopes. Korg’s specifications list six operators, one filter, three EGs, three LFOs, three effects, a step sequencer, and an arpeggiator, with 40 preset algorithms plus a user algorithm stored with each program.
What sets it apart from older FM synths is that each operator doesn’t have to be an FM operator. On the original opsix, each one can run in one of five modes: FM, Ring Mod, Filter, Filter FM, or Wave Folder. The opsix mk II adds a sixth, Effect. That lets one operator filter or fold the output of another inside the algorithm.
Each operator picks its oscillator from a built-in list. Korg lists 21 waveforms on the original, including Sine, Sine 12bit, Sine 8bit, Triangle, Saw, Saw HD, Square, Square HD, several additive waves, and noise; the mk II lists 23. Polyphony is 32 voices on the original (as low as 24 depending on settings) and 64 on the mk II.
Wavetables on the opsix
The opsix doesn’t load user waveforms or wavetables. Korg’s specification pages for both the opsix and the opsix mk II list a fixed set of oscillator waveforms and describe no import function, and the opsix has no equivalent of the Sample Builder app that brought user samples to the wavestate. Its waves are single built-in shapes rather than tables, so there’s no frame position to scan either.
So a WaveStack table can’t be loaded into an opsix, and WaveStack has no opsix target. That says nothing against the instrument: the opsix gets its range from FM, ring modulation, and operator-level filtering and folding, which is a different approach from scanning frames.
If you want Korg hardware with your own tables, the Korg modwave imports user wavetables through its Editor/Librarian, and modwave native does the same in a DAW. WaveStack exports straight to it, and also to the Waldorf Iridium and plugins like Vital if you’d rather work in a DAW.
There’s one indirect route if you want a WaveStack sound alongside an opsix patch: render the table in a synth that loads it, record that, and layer it with the opsix in your DAW or a sampler. That’s a recording, not a waveform on the opsix itself, so you lose the opsix’s per-operator control over it. For FM-style sounds built from your own tables, a synth that imports them is the more direct path, and the export target pages list the frame sizes each one expects.
Specifications
| Synthesis | Altered FM, 6 operators |
|---|---|
| Operator modes | 5 (mk II: 6) |
| Oscillator waveforms | 21 built in (mk II: 23) |
| Algorithms | 40 presets plus a user algorithm per program |
| User waveform import | None |
Frequently asked questions
Can you load custom waveforms into the Korg opsix?
No. Korg’s specifications for the opsix and opsix mk II list a fixed set of built-in oscillator waveforms (21 on the original, 23 on the mk II) and no way to add your own. There’s no sample or wavetable import, and no Sample Builder support as on the wavestate. Each operator can still be bent a long way with FM, ring modulation, filtering, and wave folding.
Is the opsix a wavetable synth?
No. The opsix is an FM synth, which Korg calls Altered FM. Its six operators each play one built-in waveform and can modulate, filter, ring-modulate, or fold each other according to the algorithm. A wavetable synth scans through a stack of frames instead. Korg’s wavetable synth is the modwave, which also imports user wavetables, and WaveStack exports to it directly.
What waveforms does the opsix have?
Korg lists 21 oscillator waveforms on the original opsix and 23 on the opsix mk II. They include Sine, Sine 12bit, Sine 8bit, Triangle, Saw, Saw HD, Square, Square HD, a set of additive waves, and noise. Every operator can use any of them, so an algorithm can mix plain sines with brighter additive shapes. The list is fixed, and you can’t add your own.
Can I use WaveStack wavetables with the opsix?
No. The opsix has no way to import user waveforms, so there’s nothing for WaveStack to export to, and WaveStack has no opsix target. If you want to hear your own tables on Korg hardware, the modwave and modwave native import user wavetables, and WaveStack writes exactly the format Korg documents for them, 2048 samples at 32-bit float or 256 samples at 16-bit.
What’s the difference between the opsix and the opsix mk II?
From Korg’s specifications: the original opsix plays 32 voices (24 in some settings), and the mk II plays 64. The mk II lists six operator modes, adding Effect to FM, Ring Mod, Filter, Filter FM, and Wave Folder, and 23 oscillator waveforms against the original’s 21. Neither model imports user waveforms or wavetables, and neither has a Sample Builder equivalent for user samples. Both are FM instruments built around their fixed waveform lists.