On most synthesizers I enjoy going quickly through some presets and usually pick one to start modifying as a way of exploring the synth engine. Neither of those happened here, the former for a good reason and latter for a bad reason. It is impossible to quickly go through the presets. Each and every preset is like learning a new instrument as you explore velocity, after touch, the mod knobs, pitch bending, etc. I probably spent two days on one of the violin patches alone. I thought the Genos2 had pretty good articulations, but I never felt like I was learning what a violin was fully capable of until the Osmose. This was true with many other instruments (I can't call them presets any more) on the Osmose. The combination of expressivity and complex synth engine is inspiring in a way that's hard to describe.

So why isn't it a 5 star review? Well, modifying presets isn't like other synths. You can't say it's menu diving because the only controls for each instrument have to be exported as part of the patch. The synth programming takes place in an app and is about as fun as creating an Excel spreadsheet. In fact I have to express the greatest respect for those who have created the incredible instruments you get to play on the Osmose. But... I'm a software engineer and architect by trade and music is what I do that isn't writing code or filling out spreadsheets so for me this was clashing in a bad way.

Shouldn't the expressivity garner a 5 star review in spite of the synth engine? Well, not for me. I love the wobbly keys, but only when I wobble them on purpose. There are way too many unintentional pitch bends if I play with much energy so it really only gets used for slow pads and melodies and very careful (read slow) chords. I love the expressivity in the aftertouch and velocity controls but when you compare it to a conventional synth with knobs and wheels and sliders, well I like those too. If this keybed was dropped into a conventional analog synth with an appropriate mod matrix for what the keybed can do, and I had a mess of knobs and sliders to go with it, I would love it to pieces. Which brings me to the PolyBrute 12 problem. While the pitch bending in the key is not a part of the PB12's armament, everything else is right there. It has a great synth engine that speaks the same language synthesists do and a mod matrix to die for and other expressive options like the ribbon controller, the Morphe pad with its own xy and pressure, etc.. Obviously the PB12 does not do the acoustic instruments in the same way which does leave a little space for the Osmose, and if you're a VST guy or gal, then Osmose plus Omnisphere or other MPE enabled soft synth will probably be quite satisfactory for certain use cases.

You will enjoy this if you buy it, but I don't think it will hold your attention or be your main instrument after a few weeks. It does have a niche of its own but it's a pretty small niche.

Got endless number if software synths. Originally bought it for the controller but it turned to be pretty capable as a synth.

I haven't tried working with the software yet to patch it, and without the software the synth parameters available are very limited. Usually either of these two things on their own would put me off an instrument, let alone show up together. But this is a whole new world of playing.

I'm not an especially good keyboard player, but I find I'm better on the Osmose than any of my other synths. They keys feel different, and I first I wasn't sure if I liked them. But they're solid, the matte feel gives you a little more grip, and the depth of play with the aftertouch makes for a smooth and consistent experience. Much easier to pull off a smooth filter opening or what have you.

And the patches are mostly quite usable, and some of them are absolutely stellar. I'm sure programming it is going to be a huge pain in the rear, but I think this instrument will be with me for a very long time to come.

I found playing and programing this instrument challenging at first. Just give it a minute.

Playing is intuitive and unique. Each patch invites a different tactile experience. You'll learn/create new playing techniques.

Editing the sounds from the screen is simple and versatile, but it is unpredictable if coming from OSCs, Filters, and ADSRs. Using the PC software for sound editing is not intuitive or familiar, but clearly powerful. Be ready to learn many new things.

I find the build quality to be solid for studio use. I do not like the design of the power supply, don't bump it.

I recommend this for those who want to play/perform with MPE and explore a new sound/patching paradigm. Sound designers and composers should also consider the Osmose.

It's a super fun instrument when it works. It's currently a rather large brick after the latest firmware update bricked it. ExpressiveE's tech support is incredibly slow. It's been a couple of weeks since I reached out, and still no answer, just that the dev team is "looking into it." Whatever.

There are still screens/features that say "coming soon." That's idiotic. There's no excuse to release a product with "coming soon" features.

If you've got the money to waste, then go for it and hopefully yours won't brick.

The Osmose is absolutely incredible. I've been playing on mine for 4 months now and every time I sit down with a new patch it's like I'm picking up a whole new instrument. While not the most versatile synth out there, the physical modeling paired with the added expressiveness create some breathtaking performances that I haven't seen matched anywhere else. Seeing the multiple layers of expressive control here gets me excited to see where the world of keyboards will end up in the next 10 years.

I love this thing but the synth broke within about six months. I tried all the obvious reset/upgrade fixes but nothing worked, and haven't done the support claim yet so I don't know what will happen.

I waited several years with partial payment in advance. Expressive E should have been able to make these things reliable given how much extra time they had to work on the product during manufacturing delays.

For what it's worth the editor for the synth engine is ultra complex but I still love it. It is not incomprehensible and it does things that nothing else can do. The sounds are wonderful and easy to modify into further wonderful voices. As an MPE controller and as an MPE hardware synth this thing is perfect for me. But nothing is good if it can't stand up to normal use.

I'm a classically trained pianist and have gotten used to synthesizers being something which requires a significant bit of work before / after a performance to dial in a sound. Not so with the Osmose. The amount of expressivity possible with the patches on this incredible instrument is truly on par with any acoustic instrument. There's really nothing quite like this, at least not without diving deeper into more esoteric products utilizing the eaganmatrix modular synthesizer.

Now, is this the perfect product for everyone? Probably not, if you want a synth you can play around with to easily create new sounds. The EaganMatrix synthesizer seems to be equal parts audio engineering and black magic, and the complexity of creating a new sound is on par with the complexity of creating a new software or acoustic instrument from scratch. While this is an area I think is ripe for disruption in the future, possibly using AI to handle the enormous complexity in setting up the character of instruments in response to the enormous amount of data captured by the Osmose keyboard, it is currently not practical for non-experts to create new sounds that'll leverage the full capabilities of the underlying sound engine.

Does that mean the Osmose is not a good investment? Absolutely not! It's incredible! The MPE capability means that with newer soft synths you can get a level of expressivity and modulation comparable to the internal Haken engine / eaganmatrix synthesizer. Additionally, the built in sounds have so much expressive potential that I do not for see them getting old anytime soon, the same way that a piano sounds like a piano but it's still widely used in music.


This truly is the first synthesizer I've ever played on where I felt I was capable of expressing as much intonation and detail as I could on an acoustic grand piano. Nothing else has come close. Read about the internals of the sound engine. It's capturing an enormous amount of data about the exact way the keys are pressed in order to give this level of responsiveness. Simply amazing.

My only wish is it had more keys. Make a 61 or 88 key version please!

I do hope this serves as inspiration for future synth designers to build on the underlying sound engine and provide higher level abstractions that mere mortals can use to create new sounds. For now, I'm very happy I bought this and will be spending many enjoyable hours playing it. :)

It looks good and has everything you want but the software is impossible. Is literally learning C++. The software and the manual were put together by two different people over the phone. For example "release" is called "Persistence" and is not part of the ASDR because there is none, just pre-programmed curves.

It reminds me the old Emulator user manuals where samples were explained in samples and you needed to calculate but this one is not even intuitive. Good luck trying to assign a filter... you have to navigate through the matrix and when you click you will see a window telling you "normal coefficient update rate 1kHz"... what that has to do with music? This seems like calculous.

And everything is like that, they invented their own language and the interface makes no sense. It was put together by a guy who has no clue about playing an instrument, no awareness of user experience. Probably a programmer who got upset with the client and just delivered something useless.

You will not like the software.

Even though I'm not advanced; I find the Osmose easy to use. I fits my songwriting/composing projects beautifully!

All I can say is I am constantly blown away by how epic Sweetwater is. Brendan, who I have had as my go to rep for 10+ years is always there to help me get the gear I need in order to crush live shows and studio session work. This keyboard is an absolute game changer. I have never had the ability to do what a guitarist can do.....bend strings. I have Moogs and love them dearly but I always have to use the pitch bender to create emotion. Now with the osmose, I finally feel the emotion playing a keyboard, that is similar to the feeling you could only get from a guitar.

Get this keyboard. You have to. Put your name on the list, and get ready to have your life changed forever.

Thank you Sweetwater, and thank you Brendan.

All I can say is: go watch a couple of the demo videos and imagine how expressive and simple this keybed/synth might be; then double it... and your mind will still be blown. I find something new and inspiring every time I sit down with this instrument. Buy one... even if you're not a keyboardist.

The learning curve was all of maybe 15 minutes. You basically have vibrato (range 0.25 to 48 semitones), super-sensitivity, and a mod wheel built into every key, all of which you can customize or effectively disable. The 500 built-in patches cover an enormous range and each exposes intuitive, simple, powerful controls, typically over 5 or six parameters; and you don't need to spend ages studying oscillators, filters, ADSM, FM synthesis, etc. to exploit these customizations. If you do want to go down the rabbit hole... the Eganmatrix software will keep you busy for ages :)

This is the best keyboard I ever seen, but I never had one but it's very cool I wish I could have one.

Too much fun and so addictive plus I ordered a second unit I liked it so much. You can obviously watch a million reviews so not much I can add except I'm moving my other gear out of the way &/or selling stuff to make space and access to this one. It's just so different compared to all "dead key" on/off & sustain keyboards. Even cheap (meaning cheaply made but still expensive) aftertouch enabled keyboards are still like punching a brick wall to activate aftertouch. Uncomfortable & annoying they are now once you try the Osmose. No special skills needed you can adjust it to taste & preference. It will make your regular dead-key boards come to life also when used as a controller. So it offers (4) fantastic gifts as follows: 1) Outstanding MPE action with fully implemented gestures to keep you 100% engaged & entertained 2) Fantastic EaganMatrix sound engine that can do about anything, programming not required unless you want to 3) The ultimate MPE or any style MIDI controller. 4) It's affordable to nearly anyone. You could buy the Osmose for any single reason mentioned but with these four advantages there's not a good reason not to own one and keep it for a long while. It's kind of like when the wheel was invented. You can always go back to banging notes on/off but why would you want that as your only option?

I am lucky to have one of the early units since I purchased it way back when it was a kickstarter project. The most wonderful thing about the Osmose is that to me it is a musical instrument. Not a synth - or a keyboard. It's like something completely new but also very familiar and very easy to connect with and dive into. I've owned several MPE instruments but they have really nailed it with Osmose and have done something the other companies have not been able to do in my opinion. It's so easy to start playing this and being extremely expressive. The way that some of the patches react is just insane. The highest compliment I can give Osmose is that I just can't stop playing it. I just keep wanting to come back to it, turn it on, and start playing. If you are looking for something to sequence and produce without really performing tracks it's probably not for you. it's really an instrument suited for someone who really wants to play. That said, you can definitely use MIDI to produce tracks with it, but since there is so much data involved it's not as simple and quick in some cases as your normal keyboard / synth. I use it as a MIDI controller as well. It's super easy to dial the keyboard behavior from MPE+ to regular MIDI keyboard to poly aftertouch to channel based pressure. And you can tweak the keyboard response very easily as well. I really bought it for use as a controller but the big surprise for me is how amazing the synth engine is as well!! It sounds so good and does so many things, many of which you just can't get out of other synths. I love the fact that most of the sounds are nothing like what most other synths come with. It absolutely excels at plucked, bowed, bell type, dynamic organic sounding percussion, and other worldly sounds that are very dynamic. It's also got some super interesting pad type sounds and some more standard synth type sounds, but those are in the minority. If you are looking for your normal synth bass - pad - lead - electronic type of stuff this isn't the synth engine for you. If you want extremely interesting and dynamic and fun to play sounds with a crazy level of realism as well - then this is definitely for you. I've owned probably 50 synths and keyboards over the last 10 years ranging from Behringer to Moog One and custom built. I recently decided to scale down to only the instruments I love to play and can't stop using. That goes for keys, bass, guitar, and includes mics and gear. This is the only keyboard I have right now. I use Osmose and a host of plugin synths. Never been happier with my rig before. That's not to say I won't pick up another synth or more in the future. But right now this is where it is at for me. I absolutely love the Osmose and can't recommend it highly enough!! BTW.. I compose and do sound design for a living so when I say things I use every day I literally mean it. I use it every day.