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ASM Hydrasynth Deluxe review

ASM shocked people with the Hydrasynth; now they are back with the Hydrasynth Deluxe. It’s a 73-key polyphonic morphing synth, and we can’t wait to take a look at it.

ASM Hydrasynth Deluxe review
Hydrasynth Deluxe synthesizer / Image credit: ASM

Our verdict on the Hydrasynth Deluxe 4.9

The Hydrasynth Deluxe picks up where the original left off, and it’s another complete triumph. It has an intuitive design and a bit of a learning curve, which might sound like a contradictory statement. But, it’s a design that becomes very intuitive when you know what you are looking for. Overall, it’s a unique-sounding synth with seemingly limitless possibilities; we love it.

Check availability and current price: Sweetwater

Who does it suit?

Advanced sound designers, composers, and performers.

  • Improved keyboard feel.
  • Intuitive design.
  • Extensive modulation.
  • Powerful 16-voice or dual 8-voice synth.
  • Ribbon controller.
  • Flexible routing and effects.
  • CV/Gate connectivity.
  • Unique sound.
  • Outstanding build quality.
  • Learning curve for beginners.

Signal path 4.8

One of the coolest things about the Hydrasynth Deluxe (and the original Hydrasynth) is that the signal path is clearly laid out in the Module Select section. Dedicated buttons for each stop in the chain allow you to make fast adjustments and see exactly how your signal is routed.


The Hydrasynth Deluxe features three oscillators per voice: two wavemorphing oscillators and one fixed wave oscillator.

Both types of oscillators offer 219 single cycle waveforms, keytracking up to 200%, and a +/- three octave tuning range.

Where the wavemorphing oscillators set themselves apart is with user waveforms and the WaveScan parameter. There are eight user Wavelist per oscillator.

The WaveScan parameter allows you to modulate through wavetables, creating some pretty extreme sounds.

Right from the oscillators, the Hydrasynth Deluxe is unapologetically digital. ASM is reaching for the kind of flexibility offered by certain popular synth VSTs, and putting it in a hardware unit, which is impressive.


The Hydrasynth Deluxe allows two Mutators per oscillator, with a wide selection of choices.

It starts with Linear FM with selectable Modulator source. Mutators include Wavestack, PWM, PW-Squeeze, PW-ASM, Hard Sync, Harmonic Sweep, PhazDiff, and Dry/Wet mix.

The most interesting are Wavestack, PW-Squeeze, and PhazDiff.

Wavestack produces five detuned waves, generated from the input source, and has an adjustable Detune amount. As you can imagine, it creates some pretty monstrous patches.

PW-Squeeze compresses the waveform, hence the name. But, unlike regular PWM, it only applies to the center section of the waveform.

PhazDiff combines phase shifting and summing techniques to create a new sound. You could spend the day on modulators and still barely scratch the surface.

Noise generator

A simple Noise Generator – white, pink, red, blue, brown, violet, and grey. OK, maybe not as simple as most.

Ring modulation

The Ring Modulator has selectable input sources, so you can choose which of your oscillators and Mutator outputs are affected by it.


There are two filters that can be routed in series or parallel. It’s good to see these routing options; it adds another level of control over your output.

Filter 1 has various modes, starting with a 12/24 db modern ladder (compensated or uncompensated).

Then it starts to get much more interesting with a Threeler Highpass/Lowpass filter and MS20 Highpass/Lowpass filter.

The MS20 filter is very popular, but the Threeler (Ian Fritz) filter is more of an acquired taste. That’s not to say you won’t love it; it’s just one of those filters that divide opinion in the Eurorack community.

Beyond those, you have a Low Pass Gate, one/eight pole Lowpass, and a Vocal filter with Formant and multiple vowel order parameters.

Filter 2 has two continuously variable filter modes. The first is Low Pass, Band Pass, High Pass, and the second is Low Pass, Notch, High Pass. The second mode gives you that creamy smooth Oberheim sound.

You might not love every single mode, but the two available filters are so flexible that it doesn’t matter. You’ll find plenty to like here.

Modulation 4.9

The Hydrasynth Deluxe has an abundance of modulation options with some unique and creative quirks.


The Hydrasynth Deluxe offers five LFOs per voice, with some very cool features.

The one that most people seem to be excited about is Step Wave, which works like a step sequencer. You get 64 steps with step smoothing, glide, and semilock for pitch sequencing.

Step Wave allows you to create colossal moving, rhythmic, percussive patches (especially in Multi Mode) that you don’t hear from many other synths.

Other LFO modes include Clock Sync, Fade In, and Trigger modes (mono, poly, free).

Envelope Generators

Like the LFOs, there are five Envelope Generators available per voice. More importantly, they are extremely flexible six-stage DAHDSR Envelope Generators rather than the more common ADSR format.

Adding to that flexibility, you have slope curves for the ADR stages and the option to set tempo or time length of each stage.

You can even loop the AHD stages to create new modulations, similar to an LFO.

There are also Trigger modes with up to four Trigger sources per Envelop Generator.

Modulation Matrix

A 32-Slot Modulation Matrix provides plenty of routing options for modulation sources and destinations.


There are eight Macro knobs, assignable to eight destination controls or as modulation destinations. The knobs allow for positive and negative values, which are visualized nicely on the OLED screen.


The Arpeggiator offers all the usual things with a few lovely additional features. It’s multi-directional, including up, down, up/down, note order, random, and so on.

You can arpeggiate each keyboard split section independently in Multi Mode, which is both chaotic and wonderful.


We didn’t mention the effects in the signal path, but you can see they come in three stages; Pre-Effects, Delay and Reverb, then Post-Effects.

Pre-Effects and Post-Effects include Chorus, Flanger, Phaser, Lo-Fi, Tremolo, EQ, Compression with sidechain, and Distortion. So, you can see there are many options, but what’s even better is the ability to position them where you like in your chain.

The Lo-Fi effect is a really nice addition, too. Six Delay types and four Reverb types sit between pre and post.

Sound design 4.9

Many analog purists will look at the Hydrasynth Deluxe like it’s just another digital synth that doesn’t measure up. Of course, the trade-off is that digital can do more, but it lacks analog warmth.

However, the Hydrasynth Deluxe is something a little different. It embraces its digital roots and delivers limitless morphing sounds and textures. The sheer amount of modulation available means it’s very unlikely that you’ll struggle to create something unique, even after years of use.

The heart of the sound design capabilities comes from the two main modes: Single and Multi.

In Single Mode, you have a powerful 16-voice synth. In Multi Mode, you have dual eight-voice synths that can be split (with Crossfade) or layered. Whatever it lacks in a true analog vibe, it more than makes up for with digital abundance. It’s a sound designer’s dream.

In use 4.9

The two main areas you will use a synth like this are on stage and in the studio. Sometimes, certain features or quirks are more important for a specific use, but in this case, it comes down to the workflow.

When a synth does as much as the Hydrasynth Deluxe, nothing matters more than navigating quickly and easily.

Surprisingly, ASM has managed to put together a very intuitive set of controls. You can be very hands-on with the synth, and any menus are easy to get to.

Each section, from Main Controls to Master Controls, is very well laid out.

In terms of performance, the keyboard still has polyphonic aftertouch, but the feel has been improved (including note-off velocity) since the original model. it now has

It also has a lovely Ribbon Controller that can manipulate everything or a single keyboard split zone.

Connectivity 4.8

Potential buyers will be pleased to hear that the Hydrasynth Deluxe has CV/Gate connectivity. It opens up the world of endless Eurorack possibilities.

CV/Gate options include two Mod inputs, two Mod outputs, pitch out, gate out, and clock out.

It has two main/upper 1/4″ audio outputs and two lower 1/4″ audio outputs.

Dual headphone outputs (1/4″ and 1/8″) and 1/4″ expression and sustain pedal inputs.

Build quality 5.0

Much to our surprise, the original Hydrasynth was very well built, considering the price. The Hydrasynth Deluxe follows suit with full metal construction and smooth edges/finish.

The side panels are metal rather than wood, and for the image of the Hydrasynth, they work better.

All of the knobs feel and look great, too. The mod and pitch wheels are solid, but a little pet peeve might be that they are slightly chunky.

Compared to other synthesizers

The Hydrasynth Deluxe is a versatile synth, but no instrument will please everyone. Here are a few alternatives.

Hydrasynth Deluxe vs. Yamaha MODX7

Yamaha’s MODX7 is an excellent synth that over-delivers; it’s a workhorse. For us, the Hydrasynth Deluxe offers something more unique.

Hydrasynth Deluxe vs. Sequential Take 5

The Sequential Take 5 might not be the most direct competitor for the Hydrasynth Deluxe, but it’s a chance to get some of that iconic Prophet 5 magic on a budget.

Hydrasynth Deluxe vs. Moog Subsequent 37

We added the Moog Subsequent 37 as a performer’s choice. If you play funk, hip hop, or anything similar, this classic could be the one for you.

ASM Hydrasynth Deluxe prices and deals

Check availability, prices, and deals: Sweetwater