Image source: Terrence O’Brien / Engadget
If you move from left to right in the signal chain, the next thing you will come across is the Mutant 1-4 buttons. Press one and the OLED on the right will show the parameters. (Are you noticing a trend?) Depending on which mutator you select with the upper left encoder, you will see different control options here. But basically you just turn one knob to select, say PWM, and then another to set the Wet / Dry value you want.
There are eight different mutators to choose from, but I want to focus briefly on PW-ASM or Pulse Width ASM. There are two things that make the Hydrasynth pulse width modulation special. First, you can use it on any waveform – usually PWM is associated with square waves. Second, in ASM mode, you can create your own custom pulse width patterns. PW-ASM divides a wave into eight different sections and you choose the amount of modulation around each of the slice points. It’s not the easiest thing to explain, but suffice it to say that I have not seen any other synthesizer with this feature. (If so, please tell me in the comments.)
Below the mutants is the button to enter the ring modulation and noise parameters, and then if you follow the line that illustrates the signal chain to the right, you will see that they all flow into the mixer. Here you can adjust the volume of each oscillator, the ring mod and the noise area, as well as the panorama for each. And here you also decide how much of each should be sent to which filter and whether the filters are in series or in parallel. This is one of the sections with the most page of scrolling options, but it’s still simple. Just press the up and down buttons next to the display until you see the parameter you want, then turn the knob next to it.
Terrence O’Brien / Engadget
After the mixer, the signal chain branches out again with your envelopes (ENV) at the top, LFOs at the bottom and bottom in the middle of your audio signal, including filters, amplifiers and effects.
By default, ENV 1 and LFO 1 are connected to the filters, while ENV 2 and LFO 2 are connected to the amplifier. There is no way to break the connection between ENV 2 and the amplifier, it always determines the overall volume of your sound. That doesn’t mean you can’t control the volume of the oscillators separately; it just means you have to get creative.
So if you want OSC 2 to come a little after OSC 1, you can use ENV 3 to control it, just with a slightly longer attack time than ENV 2. To make the connection you can use the Mod Matrix button Press above and scroll through all options. The easier way, however, is to hold down the ENV 3 button and then press the Mixer button. Then these two modules are automatically connected and you just have to select the desired parameter (in this case OSC2CVol) and set the depth. It’s also worth noting that the Hydrasynth’s envelopes have six stages – Delay, Attack, Hold, Decay, Sustain, and Release – unlike the more common ADSR. This means that you can actually delay the start of the envelope by a certain amount of time after pressing a key.
The LFOs are even more interesting. While you can use them to create noisy filter sounds and soft pitch lashes, you can also use them as a sequencer. In Step mode, you can create a custom modulation pattern with up to 64 steps.
However, on the fourth page of the LFO settings you will find the SemiLock option – this is where the magic happens. See, Hydrasynth doesn’t have a proper sequencer, but you can use the LFOs locked to semitones thanks to the latest firmware. So with very little work, OSC 2 could get behind OSC 1 and play melodies on a pad. This is just one example of how you can harness this power. You can sequence everything from the filter cutoff to the wet / dry mix to the reverb to the detune or glide time or even the parameters of the mutators. This level of control opens up a whole world of possibilities.
At the end of the signal chain you have four effect slots that you can work with: a pre-FX, a post-FX and dedicated delay and reverb modules in between. There are different variants of the latter two. The reverse delay is excellent, and while the plate and hall reverbs are solid, my favorite setting is Cloud.
The Post and Pre-FX sections have the same options to choose from, including Phaser, Distortion, Compression, Rotary, Tremolo, and more. But my favorite at the end of almost every patch is lo-fi. You can lower the sample rate to get some squashed digital sounds and there are several types of filters to choose from that will give you the quality of something played on a phone or radio. It’s just a nice touch so it doesn’t get too crispy and clean.
Here’s the thing: this just scratches the surface of what the hydrasynth is capable of. There are a number of options in the Voice menu to add depth and warmth, such as the type of vague analog feel. There is an incredibly powerful arpeggiator with eight different modes. There is a Macro Section where you can assign multiple parameters to a single knob to dramatically transform sounds in a performance-friendly way. And I hardly mentioned the keyboard with polyphonic aftertouch – something that has basically never been there at this price.
Terrence O’Brien / Engadget
The Hydrasynth Explorer is, at least under the hood, almost indistinguishable from its larger counterpart, the Hydrasynth Keys, which cost almost twice as much. So what are you giving up here? Well, one of the Explorer has mini keys instead of large keys, but that might not be a disadvantage for some people like me with small hands and limited piano knowledge. There are also no real pitch and mod wheels, but touch strips; They’re fine, but not nearly as accurate. The biggest loss is the reduced number of controls. The filter controls have been reduced from five to three, and there are only four macro / parameter controls compared to eight on the larger models. But frankly, those are small sacrifices to get at that price.
Finally, ASM has to describe the Hydrasynth Explorer as “portable”, but that is only true in the most technical sense. In addition to the supplied power adapter, you can operate it for three to four hours with eight AA batteries – which is not a trivial amount. The Explorer also weighs 7.5 pounds and is nearly 22 inches long. Sure, that’s dainty compared to the 22 pounds and 32 inches of the Hydrasynth Keys, but that’s not something you toss in a backpack and take to the park on a whim. While it’s easy enough to toss the trunk and take to a jam session, ASM doesn’t undermine a travel suitcase for it, or undermine portability.
