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Ashun Sound Machines Hydrasynth Keyboard Synthesizer

Hydrasynth 49-Key, Keyboard Synthesizer with ASM PolyTouch Keybed, 4 octave (67 cm, 26.4"), Ribbon Controller, 5 Banks of 128 Patch Memories, CV Gate Input and Outputs, and USB Connectivity.


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Discounted Price $1,299.00
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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, Ashun Sound Machines 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 Ashun Sound Machines' 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, ergonomically designed pitch, 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 ASM Polytouch keybed allows not only the standard velocity and aftertouch found on other keybeds but supports fully polyphonic aftertouch. In recent years companies have been trying to find ways to give the keyboard musician more ways to better express themselves. The problem is that their solution is almost never a keyboard, so you have to learn a new technique to play them. The Polytouch keybed features a high-quality, standard sized keys, so you can start playing it instantly.

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 wave tables. Creating user wavetables is arduous or downright impossible. Unlike most wavetable synths, Ashun Sound Machines' oscillators 1and 2 have Wavelist mode. This mode allows you to pick and choose 8 waves, from our bank of 219, arrange them in the order you want, and then morph from one to another.

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.

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.

  • 8 Voice Advanced Wavetable synthesis

  • 2 Wavemorphing Oscillators
  • 219 single cycle waveforms
  • User wavetables - 8 user selectable ‘wavelist’ per osc to build user wavetables
  • Every osc and patch can have its own user wavetable
  • WaveScan parameter for modulating through wavetables.
  • Keytracking – 0-200%
  • +/- 3 octave tuning range
  • 1 fixed Wave OSC
  • 219 single cycle waveforms
  • +/- 3 octave tuning range
  • Keytracking – 0-200%

  • Dual Mutators per oscillator
  • FM – Linear FM
  • Selectable Modulator source
  • Built in Sine & Triangle, OSC1, OSC2, OSC3, Mutators A, B, C, D, Noise gen, Ring Mod, External Mod 1&2 input.
  • WaveStack – Generates 5 detuned waves from input source. Detune amount.
  • Pulse Width Mod – Adjust pulse width of ALL waveforms.
  • PWSqueeze – Compresses the center section of the waveform. Differnnt type of PWM
  • PW-ASM – 8 User adjustable wave squeeze/stretch points.
  • Hard Sync – gives that classic sync sweep sound.
  • Selectable Sync input source.
  • Harmonic Sweep – will scan through the harmonics of the incoming sound.
  • Dry/Wet mix to blend the original OSC source.

  • Noise Generator
  • White, Pink, Brown noise sources

  • Ring modulator
  • Selectable input sources
  • OSC1, OSC2, OSC3, Noise, All Mutator outputs, External Mod ½ in.
  • Depth control

  • Sound source mixer
  • Mix the following sources - OSC1, OSC2, OSC3, Noise, and Ring Mod.
  • Panning for each source
  • Filter routing mix
  • Solos for each source (solo status is saved in the patch)

  • Two Filters
  • Series or parallel routing
  • Filter 1
  • 12 & 24db modern ladder (compensated)
  • 12 & 24db vintage ladder (uncompensated)
  • Threeler HP, LP
  • MS20 HP, LP
  • Low Pass Gate
  • Vocal filter
  • Multiple vowel order parameter
  • Formant parameter

  • Filter 2
  • Continuously Variable Lowpass-Band pass-High pass (Oberheim SEM style)

  • 5x Low Frequency Oscillators
  • 10 static waves
  • Sine, triangle, Square, Saw up, Saw down, S&H, Low random, Noise, Pulse width 25%, Pulse Width 12.5%.
  • Step Wave – 8 steps that the user can set (like a step sequencer).
  • Step smoothing
  • Step glide
  • Clock sync
  • Starting phase
  • Start delay
  • Fade in
  • Master output gain
  • Trigger modes – mono, poly, free
  • One shot mode

  • 5x Envelope Generators
  • 6 stage DAHDSR envelopes
  • Delay, Attack, Hold, Decay, Sustain, Release
  • Slope curves for ADR stages
  • Variable from full exponential to full logarithmic
  • Tempo or Time option for setting length of each stage.
  • Looping of AHD stages for creating LFO types of modulations.
  • Trigger modes – Legato, Reset, Retrigger

  • Matrix modulation
  • 32 slots for source-destination mod routings with amount
  • Modulation matrix slots can be mod destinations

  • 8x Macro knobs and buttons
  • Each macro knobs allows positive and negative of up to 8 destination controls

  • Arpeggiator
  • Arp parameters can be modulation destinations.
  • Modes
  • Up, down, up/down, Up&down, random, note order, chord, pattern
  • Octave
  • Range, 1,2,3,4
  • Play order
  • Up, down, up/down
  • Swing
  • Gate time
  • Ratchet – repeats notes
  • Chance – sets how often the ratchet takes place.

  • Pre-effects – before Delay and Reverb
  • Chorus, Flanger, Rotary, Phaser, Lo-Fi, Tremolo, EQ, Compressor (with side chain)
  • Delay
  • Tape, Ping-pong, Analog, PitchShift, Reverse, Filter delay
  • Reverb
  • Hall, Room, Plate, Cloud
  • Post-effects – after Delay and Reverb
  • Chorus, Flanger, Rotary, Phaser, Lo-Fi, Tremolo, EQ, Compressor (with side chain)

Get your Ashun Sound Machines Hydrasynth Keyboard Synthesizer today at the guaranteed lowest price from Sam Ash with our 45-day return and 60-day price protection policy.

Things You Will Get:

  • Synthesizer
  • Power Supply

Reviews are right...this is a great synth


I have a number of synths, but this is immediately my favorite. Start with the keyboard, reasonable touch, but extremely nice aftertouch. Just so expressive. Great ribbon, with Goldilocks touch. The layout is just so intuitive, select a module from the block diagram of keys and instantly all the editable parameters are right there in the display. How did ASM manage to come up with a synth so simple and yet so deep all at the same time? Looks like it was designed by a musician or sound designer, not a software or hardware engineer. And I'm only getting started with the modulation matrix and arpeggiator...


San Diego, CA


Outstanding for sound design


The ease of use and intuitive design layout make patch design fun and productive. The USB connectivity is fairly limited - it would be nice to see more features come out in the future for that.



Great digital synth!


great digital synth , give you different sound pallet because it's not as limited as analogs and analogs are perfect too .



Hydrasynth Keyboard Synthesizer

5.0 3


Synth Type Analog
Synthesizer Format Keyboard Synthesizer
Number of Keys 49
Controller Types 22 knobs, pitch bending wheels
Oscillators 2 Wavemorphing Oscillators
Wave Memory 5 banks of 128 patch memories
Effects Type
  • Pre-effects – before Delay and Reverb: Chorus, Flanger, Rotary, Phaser, Lo-Fi, Tremolo, EQ, Compressor (with side chain)
  • Delay: Tape, Ping-pong, Analog, PitchShift, Reverse, Filter delay
  • Reverb: Hall, Room, Plate, Cloud
  • Post-effects – after Delay and Reverb: Chorus, Flanger, Rotary, Phaser, Lo-Fi, Tremolo, EQ, Compressor (with side chain)
    Arpeggiator Yes
    Sampling No
    MIDI Sequencer No
    Audio Input Types 1 x 1/4" (Expression Pedal), 1 x 1/4" (Sustain Pedal)
    USB Yes
    Power Supply Type DC input jack
    Weight 22.05 lbs
    Dimensions 31.5 x 13.78 x 4.05 inches (LxWxH)
    Series Hydrasynth Series
    Model HSKB
    Information not available

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