If someone asked you to design an uncompromising analogue Eurorack mixer, it would probably look like the Xcelon. It would have mono or stereo channels, decent faders, good metering, adjustable gain, proper stereo effect sends and returns, solid clickless mute buttons, switchable outputs and CV control over everything. You’d want proper‑sized knobs, useful LEDs and for it all to fit into a compact space. The Xcelon is almost all these things and more and may even tempt those using external consoles to consider pulling the mixing into the rack. All it asks is that you embrace the density of patch cables that inevitably overwhelms it from all sides.
In 48HP, Boredbrain have squeezed in only six channels, but over a third of the space is used up by 50 patch points, over half of which are CV inputs. Each channel is nicely spaced, with half the height given over to the 45mm fader alongside the LED meters, mute button, destination switch and XFADE button, which we’ll come to in a moment. You’ve then got two large knobs for the effects sends and smaller knobs for gain and balance. All the controls fit well and feel good; there’s just enough room for it not to feel cluttered or cramped, which is one benefit of moving all the inputs to the side.
For connections, on the right side, you have two assignable mix outputs and two stereo effects sends and returns, which are also assignable and have knobs to control the return level. But it’s the input section that’s a lot more interesting. Each channel has a collection of six inputs. There’s a stereo input, which can also be a mono input or dual mono inputs, and this is where the XFADE comes in. With XFADE engaged, the balance knob becomes a crossfade between two mono sources going into that channel. This is a very neat way of increasing your channel count for things that don’t need panning. The remaining four patch points give you CV control over the volume and balance, as well as two effects send amounts. This opens up several interesting modulation possibilities and also gives us the possibility of using channels as VCAs.
While pushing all the patch points to the sides does make the Xcelon a bit bloated, the benefits of keeping the interface uncluttered should not be underestimated. The gain control is really well implemented, with lots of gain for matching wayward modules all the way to line level, plus a useful peak LED. The faders are particularly fingerable, and I like the way the glow increases as you push it up. This also comes into play when modulated with CV. There’s an A/B output switch on the effect returns, meaning that you can quickly cut effects out of the signal chain, and I appreciate the larger effects send knobs that lean into effects as being part of a playable interface. And then there’s the CV control that just wants to make you pump in a load of movement. These things along with the space and clarity make the Xcelon a thoroughly enjoyable and comprehensive mixing experience that doesn’t seem to suffer from compromises made on many other Eurorack mixers.
However, the Xcelon is merely the central hub of a whole system that Boredbrain are developing around it. On the back, alongside some jumpers that change the behaviour of the meters, effects sends and volume CV, are two expansion slots. You can add an XP3 three‑channel expansion module to each. These add three extra channels, just like the original six, that route to the same master outputs and effects. They have their own bank of CV control and can effectively turn it into a nine‑ or 12‑channel mixer. Sadly, they don’t fit perfectly, as whatever side of the Xcelon you place it there will always be a patchbay in the way.
There are also expansions for direct outputs, letting you route channels for multitrack recording. The TRS module gives you a dozen balanced outputs or six stereo outputs on quarter‑inch jacks. The DB25 module has three eight‑channel D‑Sub connectors for 12 stereo or 24 balanced audio outputs. Lastly, there’s the I/O module that has 30 channels of input or output that can be used to adapt to the TRS or DB25 modules or provide Eurorack outputs for the Xcelon.
Ecosystem
What’s missing, perhaps, is a master section and EQ, but Boredbrain have already thought of that with their Monitr and EQx5 modules. The Monitr provides two stereo channel output controls that pairs perfectly with the Xcelon, and you also get a headphone output with channel cueing. The EQx5 is a five‑band CV‑controllable equaliser that would need to be patched in before the Xcelon as there are no insert points. Six channels of EQx5 would get a bit unwieldy in your rack, and I wonder whether a simplified version with rear connections would make for a great future expansion. All in all, if you add the two expansions, the Monitr output and the DB25 to cover all the direct outputs, you would be eating up 110HP and wouldn’t get much change from £2400, but there’s nothing quite as comprehensive, versatile or as extraordinary as this system in Eurorack right now.
There is a lot going on in terms of cabling and connectivity, which can threaten to drown out the sublime mixing experience. However, provided you keep your spaghetti under control and can afford the investment in money and HP, the Xcelon has the space to provide a solid interface for pro‑level recording and a playground for live performance while feasting on the modular mayhem of CV control.
£929
$899