Opsix - Altered FM Synthesizer
Opsix - Altered FM Synthesizer
Opsix - Altered FM Synthesizer
Opsix - Altered FM Synthesizer
Opsix - Altered FM Synthesizer
Opsix - Altered FM Synthesizer
Opsix - Altered FM Synthesizer
Opsix - Altered FM Synthesizer
Opsix - Altered FM Synthesizer
Opsix - Altered FM Synthesizer
Opsix - Altered FM Synthesizer


Opsix - Altered FM Synthesizer

£549.00 Sale Save

Opsix takes traditional six-operator FM synthesis, expands into brand new areas, allowing easy control in real-time via a full complement of knobs and faders. Five operator modes, 40 algorithms with user mode, extra waveforms, new and classic filters, incredible effects, 16-step sequencer and legacy FM compatibility complete your Altered FM journey.


Rethink everything you know about FM synthesis.

The Opsix is a six-operator “altered” FM synthesiser that has an easily accessible "hands-on" mixer and powerful sound engine that goes well beyond traditional FM. The Opsix opens the creative potential of digital synthesis with astounding sonic quality that keeps you coming back for more. If FM was the sound of a generation then Altered FM is the sound of the ages.

The Opsix is an instrument for players of all generations—with a new and easily accessible approach to sound design it is perfect for studio or stage. Whether you are new to synths, looking for a completely unique addition to your sound palate, or an original FM purist, Opsix will deliver on all expectations and more.


True six-operator FM synthesis, and more

The Opsix is a new digital synthesiser that features our newly designed six-operator sound generator. Although the instrument has a six-operator FM sound structure like the classic FM synthesisers, the Opsix doesn't just reproduce their sounds—it reimagines them. Using a selection of waveforms and operator modes that go beyond the realm of traditional FM, and a filter that brings together a fusion of subtractive synthesis. Opsix simplifies FM so that you can focus on exploring sounds as well as programming them. Simply put, Opsix offers the editing of analogue synths to control the power of arguably the deepest type of digital synthesis.


True six-operator FM synthesis, and more


FM exploration, easier than ever

The knobs and sliders with two-coloured LEDs on the Opsix lets you quickly and clearly see the relationships between operators, whose roles change with each algorithm. This lets you make direct changes to the pitch and volume for carriers, and to the brightness of the sound or the strength of the harmonics for the modulators. This gives you control of your workflow in FM by subtracting and adding sounds as if you were using a mixer or drawbars!


Full editing with the DATA ENTRY knobs

In addition to the six operator mixers, the Opsix gives you another six DATA ENTRY knobs for full editing without minimising or summarising any information. You can now edit the Mode, Pitch, Level, Modulation, Filters and Effects without getting lost, thanks to the combination of six graphical parameters on the large OLED display at the centre, and the rotary encoders.

The HOME/ALGO page is the starting page for everything on the Opsix, and features major parameters including algorithms, EGs, and effects. Use this page with the operator mixer to get started with everything you need to do.


Full editing with the DATA ENTRY knobs


Five operator modes that expand FM synthesis

Of course, the Opsix is a collection of everything appealing about FM synthesis... but that’s not all. The Opsix combines the tradition of FM synthesis in using sine waves, with an expansive list of diverse waveforms in pursuit of sounds with even more complex harmonics, which can also be used as a subtractive synth offering simple filtering.

Operator modes on the Opsix are used to generate sounds that are completely outside what a traditional FM sound generator can make. The operator modes let you create sounds using modulation other than FM. The Opsix offers you a much wider range of sound creation, letting you combine the five operator modes (FM, ring modulation, filter, filter FM and wave folder) and select from a wide range of waveforms.

Five operator modes


40 preset algorithms and user algorithms

An algorithm is a combination of different operator roles and connections. The Opsix goes far beyond traditional FM synthesisers by offering 40 preset algorithms. You can also create your own user algorithms giving you full control of your creative process. 

40 preset algorithms and user algorithms


Wide range of modulation

The synthesis offered by the Opsix is made even more powerful with the processors that come at the end of the signal chain. The MOD section works separate from the operators, with three EGs and three LFOs; and 12 virtual patches make a wide variety of routing possible. Use these features for a huge range of modulation to create swelling or add rapid motion to your sounds.


Powerful filters

In contrast to FM, the FILTER section follows your creation of sounds by offering analog synthesiser-like subtractive synthesis. Select from a full range of filters you want to use, from the radical MS-20 low-pass/high-pass filter, to the powerful yet soft Polysix low-pass filter that gives your sound a “vintage” feel; as well as two- or four-pole low-pass, high-pass, band-pass and band reject filters with resonance.


Studio-ready effects

The high-definition effects you’ll find on the Opsix are ready to be used in recording or on stage straight out of the box. The Opsix lets you layer three effects simultaneously and gives you a choice of 30 customisable effects; including  a compressor, EQ, chorus, flanger, phaser and stereo delay, to distinctive effects like rotary speakers, grain shifters and more. The shimmering reverb effects will add a new dimensions to the already impressive sounds.



Spectrum analyser and oscilloscope

The analyser built into the Opsix is a must-have feature for visualising FM synthesis. It shows output levels for each frequency band, so that you can see the distribution and changes to the harmonics at a glance that are caused by modulation. The Opsix also features a built-in oscilloscope that lets you check the output waveforms. The colourful changes to the sound and visual feedback are a great way to learn and better understand the sound and creative process behind the synthesis.

Cyber pad bell


Powerful 16-step polyphonic sequencer

The Opsix gives you a polyphonic 16-step sequencer that allows you to record up to six notes per step, and edit the velocity, gate time and playback timing for each note. This lets you create long phrases or make subtle shifts in timing to emulate strums or drum rolls, something that’s not possible on a typical 16-step sequencer. Also, the motion sequencer of the Opsix lets you record changes of up to six parameters, creating smooth motion changes in sound within a phrase, or building rhythms that change dramatically with each step.

While the Opsix has an easy-to-use 37-note keyboard, it also features a sequencer that rivals that of groove boxes. Just press the PLAY button—you’ll be floored by the power that this sequencer lets you unleash.

16 step polyphoic sequencer

Sometimes you just have to roll the dice

If you’re in the mood for unexpected sonic discoveries or need some extra inspiration then press the button marked with the die icon to generate a newly randomised sound. You can use the Randomise feature for the entire sound, or specify the operators, the algorithm or the sequences. You can also set the level of randomisation which lets you tweak an existing sound without completely reshaping it.

wave folder


Version 2

Download Opsix V2


Version 2

37 keys (velocity and release-velocity sensitive)
Sound generating system
Altered FM sound generator
Maximum Polyphony
32 voices (or a max. of 24 voices, depending on the settings)
6 operators, 1 filter, 3 EGs, 3 LFOs, 3 effects, step sequencer, arpeggiator
40 presets + user algorithm (unique to each program)
6 modes (FM, Ring Mod., Filter, Filter FM, Wave Folder, Effect *v2)
Oscillator waveform
23 waveforms (Sine, Sine 12bit, Sine 8bit, Triangle, Saw, Saw HD, Square, Square HD, Additive Saw3, Additive Sqr3, Additive Tri3, Additive 12345, Additive 1+2, Additive 1+3, Additive 1+4, Additive 1+5, Additive 1+6, Additive 1+7, Additive 1+8, Noise S/H, Noise White, Pink Noise, Blue Noise) (*Pink and Blue noise added in V2)
11 types (LPF 12, LPF 24, LPF MS-20, LPF POLY6, HPF 12, HPF 24, HPF MS-20, BPF 6, BPF 12, BRF 6, BRF 12)
23 waveforms (Triangle, Saw Down, Saw Up, Square, Sine, Sample&Hold, Guitar, Exp. Triangle, Exp. Saw Down, Exp. Saw Up, Step4 Triangle, Step6 Triangle, Step4 Saw Down, Step6 Saw Down, StepRnd:Time, StepRnd:Lvl&Time, StepRnd:Level, Random:Time, Random:Lvl&Time, Triangle + , Saw Down + , Saw Up + , Square +)
12 routings
30 types (Chorus, Unison Ensemble, Phaser, Phaser (BPM) , Auto Pan, Auto Pan (BPM), Flanger, Flanger (BPM) , Rotary Speaker, Auto Wah, Exciter, Enhancer, LFO Filter, 3-Band EQ, Distortion, Guitar Amp, Decimator, Grain Shifter, Master Limiter, Compressor, Delay, Delay (BPM) , Autopan Dly, Autopan Dly (BPM), Tape Echo, Tape Echo (BPM) , Early Reflection, Reverb, Shimmer Reverb, Spring Reverb)
Step Sequencer (up to 16 steps, up to 6 notes per step)
Motion Sequencer (up to 6 lanes)
7 patterns (MANUAL, UP, DOWN, ALT1, ALT2, RANDOM, TRIGGER) fault)
Number of programs
500 (250 preset programs and 250 user programs as the factory-set de
64 (16 Slots × 4 Banks)
MODULATION wheel, PITCH wheel, RATIO OP 1–6 knobs, LEVEL OP 1–6 sliders, DATA ENTRY A–F knobs
Headphone (6.3 mm stereo phone jack)
OUTPUT L/MONO and R (impedance-balanced 6.3 mm TRS phone jacks)
DAMPER (6.3 mm phone jack, half-damper not supported)
MIDI IN and OUT connectors
USB B port
Power supply
AC adapter (DC12V)
Power consumption
5 W
Dimensions (W × D × H)
565 × 338 × 90 mm / 22.24" × 13.31" × 3.54"
2.9 kg / 6.93 lbs
Included items
AC adapter
Accessories (sold separately)
DS-1H damper pedal, PS-1 pedal switch, PS-3 pedal switch
* All product, company, and standard names are trademarks or registered trademarks of their respective holders.
* Appearance and specifications of products are subject to change without notice.


All new products are sold with a 3-year manufacturer warranty when bought direct from Korg UK.
Certified Refurbished products also come with a warranty, for more information find out more about our certified refurbished products.


We offer a 30-day returns period on all products purchased directly from Korg UK. More details can be found in our return policy.