ZEBRA 3 Review
Zebra 3 is U-He’s flagship synthesizer, at the time of writing this review the public beta is out for testing, I will update this review after the official version is released. Zebra 3 is the long awaited update to Zebra. Zebra is a fully loaded hybrid and somewhat modular synth featuring wavetable and additive oscillators as well as physical modeling resonators and analog modeled filters. The updated UI is quite lovely, though I wish we’d see the light theme from Zebralette 3 as I feel that design is quite a bit more modern, I know I’ll be waiting to see what Plugmon and others come up with for alternate skins. As it is now, things are much more pleasant to look at, with visual hierarchy and contrast being much nicer.
The workflow is still quite similar to the previous version of Zebra, but with some improvements. For the most part, things are still quite tedious, lots of right clicking and menus, there’s a central matrix for adding and routing modules, some controls have a built in modulation slot, and there’s a variety of hidden windows and tabs. I think those who are familiar and comfortable with Zebra 2 will feel right at home, but I think I would have liked to see things a bit more modernized in this department. That said, there have been some improvements, the wave and MSEG editing are much more fleshed out, module options and filter types have their own popout window that is much nicer than selecting from a dropdown list, and there’s drag and drop modulation routing available (one example where the previous mod slots could simply be removed to save space).
ENGINE
Zebra’s synth engine is built around a modular grid, each slot can load one of several modules including oscillators, filters, mixers, and other effects. Modules are routed from top to bottom with the ability to patch signals between modules via right click menu options. I can understand why this system is used, but it feels a bit out dated, I’d personally rather have this space occupied with more control UI panels and simply add new modules below the existing panels. Linear routing could simply be hidden with “break out cables” being revealed whenever modules patch into other lanes or mixers.
It can be a bit tricky to navigate with all the control panels being in one long chain even though some modules are parallel and others serial. It’s not the worst thing though, I can manage just fine, and this does let you fit more signal chain on screen all at once. I call Zebra “somewhat modular” because the routing isn’t completely free and you’re limited to up to four copies of each module, and sometimes less. I do think some people will prefer this layout, I can see some advantages when working with larger patches, especially with lots of parallel routing and the module limitations are acceptable considering just how powerful each oscillator and filter are.
OSCILLATORS
The main oscillators are quite incredible, the core oscillators to Zebra 3 are hybrid wavetable/ additive synthesis, I go into much more detail about these oscillators and why they are special in my Zebralette 3 review:
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The oscillator has two main render modes, wavetable and additive. Wavetable plays back the waveform in the current wavetable frame as is, where additive renders and approximation of the shape out using an additive synth engine. Additive mode looses wavetable mode’s unison options, but gains a whole additional oscillator effect in the form of a spectral distortion modifier. This modifier includes 7 different spectral warping algorithms that really unlock some of the great additive controls you’d find in synths like Razor, Harmor, and Parsec.
There’s also two source modes, Curve Geometry, which uses the wavetable as you’d expect, to define the shape of the waveform, and curve spectrum which looks at the shape as an amplitude plot for the oscillator’s partials. This gives you multiple ways to draw audio, if you find drawing shapes to be too homogenous and similar sounding, you might enjoy sculpting the spectrum.
Additionally there are two slots for oscillator effects which can load one of 20 different processes to alter the waveform with. These can really sculpt and shape the table you’ve created in a wide variety of ways. Many of them can even use sections of the table to define their processing curve. This brings me to a useful tip, you don’t have to use the full range of a table. You might want to use half of the table for your main shape, and the other half as the effects curve. Perhaps in the future I will go through and describe each and every effect, but I’ll list some of my favorites here
It’s important to mention that the wavetables are fully vectorized, this means there are no “frames” between shapes as in classic tables, This gives you a MUCH smoother sound and one shape morphs to another. It’s Very clean and fluid. The sounds produced by this engine are phenomenal, I at no point did it feel like the engine was holding me back, or limiting the process. Nothing felt dirtier than it should be unless I intentionally wanted that. It’s quite an incredible oscillator and I can’t wait to use it in the fully fledged Zebra 3 synth that is sure to come eventually. I can’t say I understand everything yet, I currently have no clue what the morph guides are, even after reading the manual on them, so instead I just opt to utilize “curve set” instead.
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Expansion/ compression: These two effects move all harmonics of the fundamental towards or away from it
Curve: This effect is the same as both expansion and compression, but it allows you to define the distance and direction the partials take based on a drawable curve.
Clusters: These create a similar partial shifting, but instead of being based around the fundamental they push partials towards particular harmonics.
Chaos and Randomness: These effects move partials around randomly, this can be unique per keystroke in the “wild” mode, or based on a seed or pattern in “chaos patterns”
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Curve Filter: Allows you to create a filter based on the wavetable shape
Sparse: Fades out various partials in the spectrum, great for physical modelling
DeltaX: I honestly have no clue what this does, it just sounds cool, if you’re reading this, remind me to read the manual in the comments
Map-o-matic: I think this might be a phase distortion based on the wavetable, but I’m not sure, along with many others in this area of the OSC-FX, they just do some cool waveshaping, I will study and understand this more in the future.
Wrap and Zap: A variety of waveshapers and wrapping processes, these can really add some sweet overtones in certain patches
Zoom: Zooms in or out of the waveform, similar to negative sync when zooming in, and PWM when zooming out. The “center” control lets you scan which region of the wave you are zoomed in on for some uniquely interesting motion.
Posterize: smooths any motion present in the waveform, at 100% it only allows the wave to change when triggered from an external source, this can allow you to reintroduce stepped artifacts or create new blocky textures, Does not apply to the spectral distortion
Spectral Decay: Allows you to use a curve to define the decay time per partial, absolutely perfect for physical modeling.
In addition to the main oscs are FM oscillators, each FM oscillator is has two operators and an input to act as a third operator. They offer a wide range of routing options via colorful arrows. In addition to being able to set the ratio and mod depth, you get feedback and optional FM character modes. What’s really fun here is the input operator, this allows you to chain multiple FMOs into various algorithms, or use the main oscillators as operators as well. You can even add effects into the signal path for some really interesting FM signal chains.
Pairing noise or exciters with the Modal resonators creates the physical modeling oscillators for Zebra 3. These were a pleasant surprise, for one the exciter has some fun patterns that replicate strumming and flam, but what’s more “exciting” (pun intended) is the modal profiles. The profiles contain a series of partials for the exciter to resonate, 18 are included but it appears as though more can be made. You can blend between profiles with a few different blend modes and change the tone and frequency mapping with position and “disperse” controls. These modal engines sound great and add a whole extra layer of synthesis to Zebra 3, they also have a cool “arp mode” that seems to strum trough partials or play them randomly, I’m not sure exactly what is happening, but it’s capable of some really alien textures.
FILTERS
Zebra 3 offers a wide variety of filters in a cool matrix menu, with the model on the Y axis and decibel curve/filter type on the X axis. This reduces several menu options and controls into a simple gird. There are a variety of model types including Ladder, Cascade, SVF, Vanilla and some I’ve never heard of before like “impossible” and “yellow”, perhaps these are unique models for Zebra. Sadly there is no notch filter type, but there is a very nice Allpass and a cool phaser filter.
One of my favorite features of Zebra 2 was the comb filter which makes a comb back here (decided not to fix that typo). Some modes seem to have been removed while some others have been added, but there’s some really great dissonant tones available here and I’m especially happy to see a “reverb” comb filter. The comb could arguably be another one of the physical modeling oscillators, it sounds great and can really add some strange dimension and texture.
EFFECTS
The effects have their own little grid matrix as well, you only get two of each effect, so it’s more like having a large pedal board than a full modular effects section.
Some of the effects also have engine counterparts, for example the ring, folder and distortion are available as oscillator effects and can be routed per voice in the main signal chain. There’s a lot you can do with these effects, but I think with how amazing Zebra 3 can sound, it’s better to leave your signal mostly dry and use more powerful external effects to add those finishing touches. Though, having effects built into your presets always gives you a better preview of how we should expect to mix them.
I’m not a huge fan of the effects, they sound good, but aren’t the most exciting. They work just fine for post processing, but compared to the amazing oscillators they feel somewhat minimal while still being a bit tedious to set up and use. The ring mod is great, especially when used in the main engine section for some cool frequency modulation. The reverb has a really nice “lush” mode, and I also enjoy the inclusion of a granular clouds style reverb that I’ll have to dig into more.
MODULATION
Modulation is where things get a bit weird, four MSEGs exist in the lower panel, these can be dragged and dropped to modulate nearly any control. For other modulation you’ll have to add them with the matrix tab or one of the built in modulation slots on any module before you can access them. This is just another one of those minor UI annoyances that I feel could have been improved upon in a newer update. You only get 4 of each modulation type available as well, so you’ll have to use them wisely.
The LFOs have sample hold and random modes available, but this means you start getting very restricted on your modulation options where I’d prefer four of each at least. There are some fun “slew” “symmetry” and “spice” controls for the LFO providing some more unique motions compared to traditional LFO shapes.
You do also get four MSEGs, as mentioned earlier, that can be looped and used as custom LFOs. What’s really cool about the MSEGs is the shape morphing feature, these basically act as LFO tables, allowing you to blend and transform between different modulation shapes. I can’t wait to make different patterns and create rhythmic patches that evolve over time.
There’s so much more I haven’t been able to cover here, like the “pitches” panel and mappers. I’m also aware I’ve had several complaints throughout this review, I think these complaints should not distract from the quality of sound and just how cinematic Zebra 3 is capable of being. As I mention in my Zebralette 3 review, the main oscillators on their own are more capable than many synths out there. So for me, Zebra is all about these main oscillators and the MSEGs, everything else is just extra. I’d sing praises for the modal synthesis alone and even the FM if you included the routing and effects. I just don’t want my criticisms to take away from my praise, I plan to deep dive Zebra 3 and use it a lot more, there is so much hidden within this engine and I think I simply dream of it being perfect. For me, this isn’t in competition with any other synth, it exists alongside the alternatives, and with so many great synths released this year alone, I have more than enough to explore and keep me busy for some while.