A triumph in design that can be the beating heart of your Eurorack system.
It's just a little ironic, then, that randomisation is what makes synth patches sound human. The key caveat that's lost even on some relatively experienced synthesists is that randomisation needs to be tightly controlled. A common stepped random voltage generally covers a huge range, generating an extreme variety of values and a sense of disorder. But running that wide-range voltage through an attenuator or a VCA means you can compress the random values into a narrow, more useable field. Routing these controlled random signals to envelopes, timbral controls, effects, sequencers, quantisers, filters or just about anything creates a subtle degree of variety that makes even simple patches feel more dynamic and lively.
I've met plenty of people with no random sources in their case, but for me, controlled random is essential to every patch. So what makes Mutable Instruments Marbles such an exciting prospect is that it puts controlled random front and centre in your system. Because it generates both patterns and melodies, it can be the rhythmic and harmonic source of a patch. It functions like a one-stop shop for making ideas, packing together functions that normally require a bevy of modules. For instance, after buying Marbles I could lose my quantiser, my Ladik random triggers and beat skippers (as great as they are), a slew generator, sample & hold and more besides.
To be honest, it's borderline disturbing how easy Marbles makes things. Even with a rudimentary understanding of its functions, I was able to get evolving melodies and beats going that had me hitting record rather than reading the manual or watching DivKid's essential video tutorial.
The x section, which handles voltages, is genius. The Steps knob in particular is thoughtfully designed. At one extreme, you hear only the root note. Turning it slowly counterclockwise introduces quantised notes of a scale, beginning with a fifth, then adding a third and a seventh, then becoming increasingly chromatic approaching 12 o'clock. Left of there the signal is slewed, beginning with nice glides and ending up in a lagging warble. The quantisation works in conjunction with the Spread knob, which sets the width of the note distribution, meaning a low Spread picks out notes from a narrow field of options while the other extreme lets through more widely varying voltages. You find yourself tweaking Spread and Steps together until you end up with a pleasing range of notes. They also work together nicely in a performance context, where Spread allows you to simplify or add complexity to a sequence by hand while Steps controls the flavour of the harmony. Adding Bias into the picture allows you to skew notes to the upper or lower end of the available range, meaning you can shift the overall pitch range of a sequence to suit the context.
On that note, Marbles can be a very hands-on, performative module. The Deja Vu section is central here. It's influenced by the Music Thing Turing Machine, which is something of a holy grail when it comes to controlled random. At bottom, it allows you to lock and loop a set of random values. Say you hear a sequence of notes you like. Hit the clear button at the top of the x section, set the length of the loop with the Length control and you have a repeating melody. With the sequenced locked, you're free to change the Length and all the other x parameters while holding on to the structure of the original pattern. If your sequence needs new content, you can ease in new values with the Deja Vu knob, slowly introducing more randomisation to your locked loop. In total, this makes for a highly intuitive set up. You can follow your ear and the module almost always spits out stimulating results that are pleasure to interact with on the fly.
The t section generates gates. It runs the gamut from steady, simple patterns built for drums to a garbled mess of bursts. Three modes decide its functions. First is a probability-based coin toss that decides whether a gate passes out t1 or t3. This is great for locking two voices into random but complimentary rhythms, especially when modulating the Bias knob to automate the probability of one gate firing over another. The Orange Mode provides a different flavour of the same dovetailing effect, where t1 and t3 multiply and divide the clock to generate ratchets, rolls or rests. Finally, the Red Mode is built specially for drums, diving the t outputs into patterns suitable for kick, snare and hat combinations. Modulating Bias here is an easy way to create generative patterns that don't sound too random. And like the x section, everything can be locked, so you can snatch what you like and add in variation to taste. The way Mutable's Oliver Gillet has programmed the code for each mode is very musical. The way the rhythms interact has a human feel to the variation and there's a lively sense of interaction to how the rhythms compliment each other.
We haven't gotten into the joys of self-patching or processing external voltages, but it should be clear that Marbles can be the beating heart of a system. The functions it brings to the table are not new, but the way they've been combined and implemented certainly is. As such, it's mainly a triumph in design. Where playability often seems like an afterthought in some Eurorack modules, Gillet has a sense for what musicians need. The code he's programmed in combination with the feature set make Marbles one of the most fun, playable options out there.
Ease of use: 4.8