ASM Ashun Sound Machines Hydrasynth Desktop/Rack Synthesizer

Get the dreamy sounds of the Hydrasynth in a smaller footprint with this desktop model. Includes pressure-sensitive touch pads for expressive performance.

The Ashun Sound Machines Hydrasynth Desktop/Rack has the same great sound engine as the Hydrasynth Keyboard. The sound engine is a sound designer's dream synth as well as a performing musician's ideal. The sound engine is designed for maximum flexibility. At the same time, ASM 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.

Check out our exclusive video demo of the ASM Hydrasynth Desktop Synth:

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.

Take a tour of the Hydrasynth:

As for the performance capabilities, The Hydrasynth Desktop/Rack has 24 polyphonic pressure touch pads so that you can play the unit without needing to connect a keyboard or other controller. Using multiple pad layout modes as well as quick to access scale modes, the Hydrasynth Desktop / Rack is easy to make music on.

The Hydrasynth Desktop/Rack comes with rack ears so that you can mount it in a standard 19" rack.

Poly Pressure Touch Pads:

One problem with many desktop or rack synths is that you usually have to connect them to an external controller to play them. The idea behind having a rack or desktop unit you can put anywhere is that it is out of the way. This is fine until you want to start doing some sound editing or adjusting it in real-time. Then you want a way read more to play it.

ASM included 24 polyphonic pressure-sensitive pads that allow you to actually play the synth. With multiple pad layouts to choose from as well as multiple scales, playing the Hydrasynth Desktop is its own musical experience.


The tone generation capability is the heart of any synthesizer.
The 3 oscillators allow you to choose from a selection of 219 single cycle waveforms.

Wavemorphing is a feature usually found on synths with preset wavetables. Creating user wavetables is arduous or downright impossible. Unlike most wavetable synths, oscillators 1 & 2 have ASM's WAVELIST mode. This mode allows you to pick and choose 8 waves, from a bank of 219, arrange them in the order you want, and then morph from one to another.


Oscillators 1 & 2 are routed into ASM's Mutants, or Mutators. The Mutants allow you to modulate, bend and sculpt the sound in new (and old) ways. Each Mutant lets you choose from the following processes:
- FM-Linear: This is for making classic FM sounds. Choose multiple FM sources, including external inputs.
- WavStack: Creates 5 copies of the input source and allows you to set a detune amount.
- Osc Sync: This gives you those classic hard sync sounds. Try hard-syncing a morphing wavetable for some fun.
- Pulse Width Modulation (PW-Orig): Performs the classic pulse width modulation on any waveform.
- PW-Squeeze: Compresses the center section of the waveform, for a unique type of PWM.
- PW-ASM: Divides the incoming wave into 8 slices and lets you set the amount of FM that is applied to each segment. This is FM unleashed.
- Harmonic Sweep: This will sweep the harmonics of the input source.
- PhazDiff: Generates the difference of the incoming wave and a version that is inverted and phase-shifted.
The Mutants can also generate their own waveforms in both FM and Sync modes so you don't have use another oscillator. Of course the routing is flexible so you can choose the other oscillators as mod sources if you like.

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. The filters can be set to be parallel or series for ultimate flexibility.


If oscillators and tone generators are the heart of a synthesizer, the filters are the soul. 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 Oscillators...YES, 5. Much like the sound engine, the LFOs are not ordinary by any means. The Hydrasynth LFOs 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. Of course, there are also 10 standard waveforms to choose from. The LFOs 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......YES 5. An advanced sound engine needs plenty of modulation sources. ASM's 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 LFOs whose shape can be voltage controlled in the modulation matrix.

Modulation Matrix:

The modulation capabilities on the Hydrasynth are endless. 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.


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.


There is the standard MIDI and USB/MIDI interfaces on the synth but ASM go deeper and allow the use of CV/GATE interfaces for connecting to the modular world. It supports the standard voltages for Eurorack modulars as well as some of the Japanese Volts>HZ products. The MOD in and outs allow for modulation from DC to full audio ranges, expanding your modulation capabilities.

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. Init and Random buttons will allow you to initialize or randomize a complete patch or specific modules with a press & hold + module select button. Pressing the HOME button returns you to navigating patches in a simple and easy way.

Master controls:

The Master Control section is where all parameter editing, patch naming, and Macro performing is done. Using OLED screens, high-resolution encoders with LED rings, and 8 buttons, this section is designed to give you good feedback on what is going on. The VOICE parameters give you access to play modes, analog feel, voice panning and many other features.


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.


The Hydrasynth comes with 5 banks of 128 patches in total. ASM hired some of the best patch designers around to create the 256 factory patches. Finding the patch you want and searching the library is made easy with the browser. The PC/MAC based Patch Manager plug-in also allows easy moving of patches to create your favorite order as well as load in new patch libraries in the future.


The effects chain goes beyond the typical ones found in other synths. 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.

The effects are the perfect way to complete your sound, in the box.
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Dimensions and Weight in Packaging
Base Item
Shipping Weight: 11.75 lbs
Shipping Dimensions: 24 x 13 x 6 in
Manufacturer Part Number (MPN): HSDR

For support or warranty questions, please contact the manufacturer:

Reviewers gave this product an overall rating of 5 out of 5 stars. (2 ratings)
Submitted January 2, 2020 by Shred Flintstone in Magic town, OH

"The best new hardware synth ,period!its a monster"

Overall: 5 out of 5 stars
(see rating details)
Verified Customer zZounds has verified that this reviewer made a purchase from us.
Everything has been implemented into this extremely powerful synth. We have a bunch of synths in our studios and this Hydrasynth is keeps and bounds better. The control panel is completely intuitive and I never touched the manual to make amazing soundscapes. The magnitude of sound design is enormous with 212 morphing wave tables, 5 Envelopes, 4 mutant osciliators., toms of studio quality effects better than some of my expensive rack gear.I don’t think there is a single thing they didn’t include in this instrument.Imagine panning in the stereo field just the oscillators.32 mod matrix slots .The ease of use is a delight.....And the sounds you can create have never been heard before...this takes Serum to the nest level. Buy this and be happy. We liked it so much we bought both the keyboard and the desktop (The keyboard is top notch, the build quality is the finest I’ve played.) And the Z has the best sales force anywhere!

Musical Background:

Pro musician and studio owner

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