New Hydrasynth Pairs Massively Deep Sound Engine With Polyphonic Aftertouch

Ashun Sound Machines (ASM) has announced the Hydrasynth – a new hardware synth that they say offers a massively deep and flexible sound engine and unique performance controls, including polyphonic aftertouch and a four-octave ribbon controller.

Here’s what they have to say about it:

“The HYDRASYNTH keyboard is both a sound designers dream synth as well as a performing musicians ideal. The sound engine is designed for maximum flexibility. At the same time, we designed the user interface in a way to allow you to edit the patch quickly with a minimal amount of paging and many workflow shortcuts.

Utilizing an advanced wavetable synthesis engine, 3 Oscillators, dual Wave Mutators and 2 filters that can be configured in series or parallel, the tone generating capabilities are unmatched.

As for the performance capabilities, The HYDRASYNTH keyboard has our proprietary Polytouch™ keybed that offers polyphonic aftertouch over each note, giving you the type of expressive control found only in certain vintage synths.

Add to this a 4 octave ribbon controller and ergonomically designed pitch and mod wheels and you have expression and control that is not equaled in any other hardware synthesizer on the market… Today or ever.”


  • Polytouch keybed – The new ASM Polytouch keybed allows not only the standard velocity and aftertouch found on other keybeds but also fully polyphonic aftertouch.
  • Oscillators – The 3 oscillators allow you to choose from a selection of 219 single cycle waveforms.
    Oscillators 1 & 2 a our WAVELIST mode. This mode allows you to pick and choose 8 waves, arrange them in the order you want, and then morph from one to another.
  • Mutators – Oscillators 1 & 2 are routed into MUTATORS. The Mutators allow you to modulate, bend and sculpt the sound. Each MUTANT allows you to choose from the following processes:
    • FM-Linear – for making classic FM sounds. Choose multiple FM sources, including external inputs.
    • Wavestack™ – creates 5 copies of the incoming sound and allows you to set a detune amount.
    • Hard Sync – This gives you those classic hard sync sounds.
    • Pulse Width – This will pulse width modulate ANY input sound.
    • PW – Squeeze – This is a different form of pulse width mod that creates a smoother sound.
    • PW-ASM – this mode divides the incoming wave into 8 slices and allows you to set how much pulse width mod will happen in each section.
    • Harmonic Sweep – this will sweep the harmonics of the incoming sound.?
  • Mixer/ filter routing – The 3 Oscillators are fed into a mixer along with the Noise generator and Ring Modulator. The Mixer allows you to mix levels as well as pan the input source. There is a balance control that allows you to choose how much signal of each source is routed to filters 1 and 2.
  • Filters – The Hydrasynth has two filters that can be configured in series or parallel. The first filter has 11 different filter models, giving you multiple options for tailoring your sound. The second filter is a 12db per octave has a continuous sweep from Low pass to bandpass to high pass, similar to the way the classic SEM filter worked.
  • 5 Low-Frequency Oscillator – The Hydrasynth LFO’s feature a STEP mode that allows you to create patterns with up to 8 steps. Having 5 mini step sequencers gives you an amazing amount of possibilities for further shaping your sound. There are also 10 standard waveforms to choose from. The LFO’s all have delay, fade in, 3 triggering modes, smoothing, start phase, one-shot mode so that they can act as envelopes and BPM sync.
  • 5 DAHDSR Envelopes – 6 stage envelopes feature Delay, Attack, Hold, Decay, Sustain and Release stages. The time settings for the stage can be set in seconds or in time divisions, giving you envelopes that play in sync to your song. You can also loop the envelopes to create LFO’s whose shape can be voltage controlled in the modulation matrix.
  • Modulation Matrix – With 32 user definable modulation routings, you will have plenty of ways to use the 29 modulation sources and 155 modulation destinations. Almost everything in the synth engine can be a modulation destination including the effects and arpeggiator. The Modulation matrix points themselves can also become modulation destinations. Modulation sources & destinations include the CV Mod In & Out jacks as well as MIDI CC’s
  • Arpeggiator – The arpeggiator allows for standard note arpeggiations but also has a phrase arpeggio built-in. Parameters like RATCHET and CHANCE will generate other rhythmic patterns with some randomness to add life and spontaneity to your performance.You can also modulate most of the parameters in the arpeggiator so imagine using LFO’s, Envelopes, Polyphonic Aftertouch or the Ribbon controller to modify your arpeggios in real time.
  • CV/GATE – MIDI – USB – Standard MIDI and USB/MIDI interfaces, plus CV/GATE interfaces for connecting to the modular world.
  • Main Controls -The Main system controls are where you navigate your patches, configure system settings and see parameters like the envelopes, waveforms, filters in the OLED screen.
  • Master controls – The Master Control section is where all parameter editing, patch naming, and Macro performing is done.
  • Macros – The patch MACROS are designed to allow the user deep control over the engine in live performance. The 8 assignable encoders and buttons can each be routed to 8 destinations. Complete sound transformations can take place with the press of a button or turn of a knob.
  • Patches – The Hydrasynth comes with 4 banks of 128 patches in total.
  • Effects – Pre-effects and post-effects give you some unique ways to process your sound. The delays and reverbs were modeled on some of the most popular effects on the market.

Here’s a tour of the ASM Hydrasynth from Director of Product Development Glen Darcey:

Here’s an in-depth look at the Hydrasynth from loopop:

Topics covered:

0:00 Intro
1:00 Overview
5:05 Keys vs desktop
7:30 Poly aftertouch
9:20 Ribbon
10:55 Chords
11:35 RGB pads
13:20 Synth engine
13:40 Oscillators
16:35 Mutant modules
22:00 Ring/noise
22:50 Mixer
24:00 Filters
28:50 Amp
29:15 Envelopes
31:30 LFOs
34:25 Effects
38:50 Voice controls
39:30 Arpeggiator
41:15 Mod matrix
44:10 Macros
46:30 CV I/O
46:45 Random
47:30 Pros & cons

Here are some first impressions from Sonic State‘s Nick Batt:

Here’s an overview and sound demo from Sweetwater synth guru Daniel Fisher:

Audio Demos:

These audio demos come from sound designer Paul Schilling, part of the sound design team for the Hydrasynth. He notes, “The first sound, GXUltraPad, uses none of the FX…only WaveStack and PWM are used to create the lush character.”

These are sound demos for the patches I have created for the Hydrasynth. It has a very broad sound palette, check out more sounds here:

Hydrasynth is expected to come out November and cost $1299 for the keyboard and $799 for the desktop version. Details are available at the ASM site.

56 thoughts on “New Hydrasynth Pairs Massively Deep Sound Engine With Polyphonic Aftertouch

  1. Impressive!

    Is this the first time a company has put both polyphonic aftertouch and a ribbon controller on an affordable synth?

    The high end of the synth market could use a shake-up, and this looks like it might do it.

    There are a lot of amazing $3,000+ synths now, but this looks like it will be a very affordable flagship synth – and one that can help push synthesis forward, rather than rehashing 40-year old designs.

    1. How do you figure it’s not rehashing 40-year old designs? There’s nothing new here – everything has been done before.

      1. The module select being able to change the individual master control displays, and then direct control over those parameters with the encoders… I’ve seen it with midi controllers, but I haven’t seen it in a standalone synth at this price point. I’ve never actually heard of PW-ASM before either.

      2. Sounds like maybe you didn’t read the article, or at least you didn’t take a look at the specs.

        Try to find another synth with 5 LFO’s & 5 envelopes per voice, FMing of external inputs, custom PWM, wave-slicing PWM, a sequencer with ratcheting and probability, CV/Gate integration to the mod matrix, polyphonic aftertouch, a ribbon controller and a price that puts it at the affordable/budget end of the spectrum for full-sized keyboards.

        Putting this into a synth that people can get for $800 or $1300 is incredible, especially when you think that the Behringer Deepmind 12 was introduced at around $1000 a couple of years ago. But this is light years beyond the Deepmind 12 on just about every level – synth engine, keyboard, expression options, build, CV capabilities, oscillator design, modulation options, etc.

        1. I didn’t say that this domination of features hasn’t been productive. I class that as a trivial difference when one talks about a 40-year range of product innovation.

          While I agree that the specific feature set of this particular ‘mangling feature set’ on a hardware synth. It’s not a very meaningful difference considering you could certainly do it with minilogue XD oscillator SDK, or 100 lines of code in any software synth.

          This is an incremental change. It’s not remarkable. It’s simply good. To something that’s going to suddenly open the gates on 40–years of development.

          I believe I’m justified considering the scope of the original claim was “help push synthesis forward, rather than rehashing 40-years of old designs.” To me, a synth of that caliber would be the very FIRST of something. This is merely one of many small changes – lots of features sure, but so did many other synths.

          I didn’t talk about cost – which is impressive (but let’s see one in the wild first) – but that seems to be an issue for some folks lately. Didn’t want to go there again other than the AT note below.

          At a minimum, I’m hard to impress. 🙂

        2. How on earth do you class $1300 as a ‘budget’ price for a 4 octave,monotimbral,digital synthesizer?

          Regardless of how much money one has or earns, $1300 does not fall into the ‘budget’ category for a synthesizer whatsoever.

          This synth is very nice, but far from perfect (monotimbral/digital… really?). Affordable for some, but not ‘budget’.

          1. Are you intentionally cherry-picking words to take issue with?

            I said it has “a price that puts it at the affordable/budget end of the spectrum for full-sized keyboards.”

            Not sure what the word police consider the cutoff for calling a synth affordable now, but this is definitely on the affordable end of the spectrum for full-size synths, right in there with stuff like the Rev 8, the MODX, the Prologue, etc. Obviously, there are some cheaper synths, like the Korg Krome or the Deepmind 12. But none of the other synths offer anything like the specs of the Hydrasynth.

          2. If you’re not willing to spend $1300 on a quality musical instrument, just stick to your free VST’s. And enjoy your hobby.

    2. The high end of the synth market could use a shake-up, and this looks like it might do it.

      Absolutely agree. it was not if but just just when a Chinese company to make a big dent into the synth market to support Poly AT !. This probably will sell very well if the hardware is reliable and they can do a good job in after-sales and support.

      The only thing is once you have a wavetable synth, you may not need another, they all seem to sound a bit similar FPGA/metallic like.

  2. I’m like the only guy that either doesn’t know or care about aftertouch. At least not enough for it to be a selling point or a pass.

    1. Aftertouch is one of the key innovations that separates synth performance from piano performance.

      With piano performance, your expression for any note is limited to how hard you strike the key. So you can’t start at pianissimo and then play louder, like you can with most acoustic instruments.

      With synths, there’s no need for keeping the limitations of the piano. The Yamaha CS80, which to many is the greatest synth ever made, had what’s called polyphonic aftertouch. This basically means that you can strike a key as hard or soft as you want, and then press into the key to control the note’s dynamics and expression over time. So you can do all those expressive things acoustic players do.

      If you just like synths because they can make cool sounds, poly aftertouch won’t mean a lot. But if you want to play expressively, it’s a huge deal, and technology is finally making it affordable.

  3. I hope they will build a sampler based keyboard with all the same layout as this great synth. This price point can’t be beat. What a smart move for a new synthesizer company to build something unique and at an affordable price.

    1. That’s a nice idea. I had a similar thought. If they kept the basic hardware and added some kind of card-slot (or just allowed you to load samples via USB, that’d be cool

      As it is though, this thing is amazing. Those folk hit it out of the park!!!

  4. I have nothing for praise for the instrument overall, especially the ribbon and price(s). My only question is this: apart from the insider group who eat up new gear, how do you get the average listener to even recognize WTF poly AT is, much less appreciate its application to anything electronic? It really shows off brass or strings, but Joe 5-Pack won’t know or care what its doing to a Mystery Synth Patch.

    I also would have preferred 5 octaves for that CS-80 full-dive-bomb ribbon experience, but I smell “practical price point.” No foul, because the CV/Gate option makes it fit more sensibly into the modular arena. 5 octaves is for keyboard >players<; 4 is more sensible for Eurorackers and certain DJ uses.

    1. I was going to say I’m comfortable with 4 octave… then I looked at my bedroom keyboard. Yup, 5 octaves. And that’s a step down from the. S80 I used to have. Lol!

  5. Just easing into this news and this seems really BIG! You’ve got a lot of plusses here, much excite to be had. I was admiring the synth control layout buttons on the right and the soft control knobs and realized this is like a 21st century ESQ-1 wet dream. I’ve dreamed of playing with paddle pw/mod wheels, i wonder if it will be as fun as i imagine. I’m off to soak this thing up some more

  6. wow, when a “no-name” can step out of nowhere with such innovative design like this, such specs and to this price, then Roland, Korg, Waldorf and Dave Smith really need to pulling themself together….else they will fall out the horse seriously

  7. Offering all these performance features on a 4-octave only keyboard is a big failure. 4 octaves are simply not enough for a performance-oriented polysynth. Such a shame really…

    1. Yeah, worst of both worlds, too big to be really portable and too small for two handed playing. It is the biggest thing that has kept me from buy the newer sequential stuff.

      1. Well that’s where the module’s come i n handy. I can just use them with my 88 key controller…..but with this synth it’s the ribbon and aftertouch that define it, so the module seems like too much of a compromise.

    2. Enough for me and MANY others. 4 octaves spans the bass and treble clef. Enough for 2 handed playing and portable enough to gig with and do live remixes when working with a DJ in a booth. Sold!

  8. I wonder what the MIDI output of a the ribbon would do. I assume the resolution over multiple octaves would be higher than 128. And: would it output different data in Theremin mode?

  9. Too sad it isn’t at least dual multitembral (layer/split) and missing a sequencer.
    I hope they bring out the PAT keyboard (with 5 Octaves) with the ribbon as a seperate controller.

  10. I do NOT understand why they went with 4 octaves. If you are going to make a performance keyboard why why why 4 octaves? Many of us have been clamoring for poly aftertouch in a modern keyboard (my SQ-80 isn’t going to last forever, and the CME and KMI units aren’t real keyboards, I have both) but to make it so much less useful makes no sense to me.

      1. I also will be waiting for the Behringer DS-80. Also heads up Behringer haters and woke synth players be warned that the Hydrasynth is made by Medeli instruments China’s largest digital instrument developer and manufacturer. This also has a “botique” design team backed by a large company.

  11. I think the 4-octave keyboard was a smart choice. You use the built-in keys for when you need polyAT, and use your favorite controller keyboard when you need more range.

    I suspect this synth will appeal to more experienced keyboardists who may not want another full-sized keyboard.

    Their release of a tabletop version is great.

    If their polyAT design is robust, perhaps we will see it in other products! fingers crossed!

    1. Is that a thing with any modern synths? I don’t remember running into that with anything since my K2500, which has to be 20 years old now.

        1. When you have a time-based modulation source, like an LFO or ENV, there is a resolution to how rapidly the synth engine changes the values of the assigned parameter. If the mod scan rate is slow, you may have zippering or limits to how snappy the envelopes ramp. If the scan rate is at audio rate, you can have LFO’s that actually go into audio frequencies and the parameters respond appropriately.

          I mostly care because you can do snappy poppy things with the envelope attack & decay if the scan rates are super fast.

          1. That’s what I thought you meant. Both the rate at which modulation is updated, as well as that ‘quantum’ of amplitude for each change of value. Thanks!

  12. The most important question is can you play Jump on it. After all, when it comes to poly synths, that’s all that matters.

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