Bela Gliss

Gliss is the new Eurorack offering from innovative company Bela. A capacitive touch sensor with alleged sub‑millimetre accuracy(!) that promises a whole lot from its startlingly simple 4HP interface. Beyond its capacitive strip it has but one button, two outputs and one input. One gets the sense that if Apple ever designed a Eurorack module, it would look and behave something like this. It’s both movement and surface area (that is, pressure) sensitive, and has a host of modes that make use of the strip in quite remarkable ways. It also lights up in an assortment of different colours, moving with incredibly high resolution.

Pressing the button and tapping the strip with two fingers opens up the Mode menu (see what I mean about Apple?). The first of the Gliss’ modes is simply called Control. CV and gate signals can be generated by drawing your finger up and down the strip, and this also takes pressure into account for two‑dimensional control. Patch the Gliss’ position output to an oscillator’s Volt‑per‑octave input and its pressure output to a corresponding filter, and presto! Instant dynamic ribbon control. Already things got even more interesting once I put Control mode into one of its Dual sub‑modes, which essentially splits the strip in two for independent pressure or position control over its upper and lower half. There are options for different latching responses, too — so I could also tailor how I wanted the Gliss to respond after letting go of it.

Signal mode visualises CV or audio and allows for attenuation, as well as inversion, clipping, scaling and smoothing. The whole strip can even become a giant high‑resolution VU meter. Notes mode presents a set of tuned notes, represented by five pre‑lit ‘buttons’ on the strip. Once again these also send CV based on surface area, so it’s much more expressive a controller than you’d think. The icing on the cake for this mode is the fact that on top of everything else, the Gliss can also act as a capable sequencer, playing back a sequence of notes with step muting, skipping or hold functions all on offer. A very nice touch (sorry).

Lastly is my favourite, Record mode, which does exactly that: draw in a gesture and the Gliss will immediately mimic it in a loop upon release. Run a finger down the strip and let go for an instant saw‑wave LFO, for example. Input gestures can be anything up to an astonishing 75 seconds long, and once again the panel can be split in two for double the value. For me, it’s in Record mode that the Gliss really shows off: gestures can be re‑triggered with a trigger to the input patch point, so custom envelopes are achievable with ease. It’s also possible to loop a string of different gestures with an external clock signal, or to scrub back and forth through a gesture shape by feeding varying voltages to the CV input. What really caught my attention in Record mode, though, is the Wavetable setting. That’s right: simply squiggle in a custom waveform, send a volt‑per‑octave signal to the CV input and play back that gesture at audio rate as a wavetable. I can’t think of another module that allows that level of impulsive customisation at that quite that speed. Madness.

Draw in a gesture and the Gliss will immediately mimic it in a loop upon release.

It’s as if Bela have thought of everything you can possibly do with a single strip of metal. But I suppose the Gliss wouldn’t be a true Bela product if it stopped there, of course. Being open source, it invites hacking and customisation, with all project files provided by Bela on GitHub. It even ships with an alternative, inverted panel, with the buttons at the bottom instead of the top. I’ll admit, it takes a fair bit of manual referencing to navigate its abstract, colour‑based menu system, so even a playing card‑sized cheat sheet (as some developers have begun including with their modules) would be tremendously useful, but it’s almost worth the occasional moment of confusion just for the elegance of the whole thing.

Now, to be clear: I am of course not going to use that lazy cop‑out of a term that any reviewer worth his or her salt endeavours to avoid when enthusing about anything as multi‑functional as the Gliss. What I will say is that it’s strongly reminiscent of a compact folding tool made famous by a certain neutral nation’s military, mainly used for cutting things but which can also do lots of other useful things very well. It can do a lot, and all of them very well indeed at that, even its modest sequencer.

The only comparable module out there to the Gliss, at least, as far as I can tell, is the Sound Machines LS1 Lightstrip, which is considerably cheaper yet offers but a fraction of the functionality of this module — a far wider gulf, in fact, than the price difference would imply (for instance, the LS1 also offers a Record mode, but with a maximum recording time of just eight seconds). Plus, we can’t escape it: with those coloured LEDs beneath its golden‑bronze panel, the Gliss is just so darn pretty! I’m certainly tempted to procure another. Outstanding.

£145.

bela.io

$149

bela.io