Majella Audio Implexus

The Majella Implexus is a beautifully made synth with a foot on both coasts.

The Implexus is a desktop analogue synth that combines elements from the synthesis schools loosely labelled as West Coast and East Coast. But never mind that for the moment — just look at it! On arrival the Implexus immediately got the household vote as the most beautiful object in the studio. Chunky steel‑shafted knobs and switches sit on a warm, smooth aluminium wrap‑around panel, finished with handmade oak cheeks. Glowing orange radial indicators accompany the primary knobs and selector pots. It’s gorgeous.

The Implexus comes with a pro instrument price tag, and a pro instrument it is. It’s as solid as it looks, has a built‑in power supply and balanced quarter‑inch audio connections. There’s full‑size MIDI and USB. As well as having a split East/West personality, it identifies fluidly between a standalone performance instrument and a modular team player. Viewed from the front it’s self‑contained, but tucked around the back there’s a Eurorack‑friendly jack field.

Coast To Coast

The Implexus is an analogue monosynth following the familiar scheme of oscillators, filter, envelopes and LFOs. It’s simple to understand and use thanks to the clearly labelled, one‑knob‑per‑function panel. Where it carves its own path is in pairing a typical ‘Basic’ sine/square/saw oscillator with a West Coast (that’s to say Buchla) style ‘Complex’ tone generator section that creates harmonically rich sounds by folding and shaping a simple sine wave.

Typically, East Coast synthesis is subtractive, using filters to sculpt tones from a harmonically intense starting point; while a West Coast synth or patch builds tone from the ground up. Rather than just mashing these two approaches together in parallel, the Implexus crosses the streams by routing the Complex Generator module through the filter, and providing cross‑modulation from the Basic Generator. But does this add up to something that sounds good? Short answer: yes. For the longer answer... let’s take a closer look.

The heart of the Implexus Complex Generator is a sine oscillator with a big octave dial and fine tuner. (A built‑in tuner can be switched between the two oscillators and shows you the delta between the current note and standard A=440Hz). Even before you get to the Harmonics and Folder sections, you can start messing with the basic sine wave using the Linear FM control. This introduces pitch modulation from the second oscillator, with fairly subtle results unless the tuning is offset between the oscillators.

The initial signal passes first through the Harmonics section which is a waveshaper, adding either odd or even harmonics depending whether it’s dialled to the left or right. This nudges the tone toward either a square or sawtooth wave. The Mod Envelope can be applied to this control, as can LFO 1. Next up is the Folder, which progressively warps the signal with the characteristic complex, metallic signature of this process. Again there’s an envelope depth control here, and also Bias, which sweeps the symmetry of folding and produces a wide variation of harmonic textures.

Mixer & Filter

The two‑person Majella Audio team hand‑build Implexi in their workshop in the Netherlands. And by ‘hand‑build’ I don’t mean ‘assemble’; we’re talking machining, cutting and chiselling as well as soldering. The end result feels like a truly premium instrument, in the way that a high‑end guitar is different to an inexpensive production‑line model.

A simple mixer section blends the two sound generation sections into the filter, along with a square‑wave sub that runs an octave below the Complex oscillator. The filter is Majella Audio’s own design, with both high‑ and low‑pass modes rolling off at 12dB/octave. For an analogue filter on a signature instrument, the filter might seem a touch well behaved on first impressions. The resonance doesn’t push to squawky self‑oscillating places and doesn’t affect the response of the filter. What the filter offers is an exceptional smoothness, which I came to appreciate as a key part of the Implexus’ sound. The filter helps define the character of the synth, without being a character filter... if that makes any sense!

The philosophy would seem to be that the filter is primarily there to round out, tame and warm the tones available at the Generator stage, rather than play a starring role in patches. This thinking could also explain why the filter only has one pre‑assigned modulation source: the Mod Envelope Generator, with a bipolar depth control. You’d probably expect the LFOs to be assignable to the filter. Audio‑rate mod from the basic oscillator could also have been considered. What’s definitely surprising is the lack of key tracking.

What you can do however is route modulation to the filter cutoff via the patch points on the back of the instrument. I was playing and sequencing the Implexus from an Arturia Keystep via MIDI so it was easy to also patch the Note CV out from the same channel to the filter frequency and achieve key tracking. As you have an LFO output and the audio output of the basic generator on the mini patch panel you could also connect the other mods that I mentioned. However, you’d have to use stackable cables to get more than one, and there’s no control over depth when making simple point‑to‑point connections within the Implexus in this way.

Modulation

As we’ve drifted into matters of modulation, let’s look at the LFOs and envelope generators. Both LFOs are the same, with satisfyingly clunky shape selectors. Five soft buttons select clock‑sync’ed cycle rates, or if you leave all the options unlit, the Rate knob sets speed manually. Clocking, by the way, can come from MIDI, a dedicated Eurorack format input, or from the Tap Tempo button.

The LFOs are dedicated to modulating the Complex Generator section. LFO 1 is applied to the Harmonics shaper with a dedicated knob. There are then LFO knobs for the depth and bias of the Folder circuit, but these can be switched independently between LFO 1 and LFO 2. This can be used to introduce subtle tonal movement, add grit and harmonics with high mod rates, or rhythmic interest using the saw and sample & hold shapes.

We already touched on the Linear FM option for cross modulating the audio sources, and if you’re following along on the front panel you’ll have noticed a couple of other Osc Mod knobs. These have the same routing as the switchable LFO mods, routing the Basic Generator to the Folder’s intensity and bias parameters. As with the FM, the results vary with the tuning of the basic oscillator. When close to the main oscillator, these mods tend to add grunge and overtones, with some subtle movement or beating. As you detune you get some satisfyingly soundtracky growls or sci‑fi effects.

As the results of these modulations are so tied to frequency, I wished that I could get independent modulation control over the pitch of the Basic oscillator. Implexus does let you apply the Mod Env to pitch, and there’s also a Vibrato with its own LFO, but they both apply across the board. This is great for shaping the overall sound and for performance, but not for making variable Osc Mod patches. The Eurorack patch panel offers some possibilities here as both oscillators have separate V/oct pitch inputs. Again, though, if you patch to these directly from the Implexus’s own envelope generator or LFO there’s no in‑built way to control depth.

Playing The Implexus

The Implexus’s main VCA is controlled by a dedicated Amp Envelope Generator. Handily this has a Drone button which holds it open so you can make sound without an external trigger. In most cases of course you’ll want a keyboard or sequencer hooked up. There are plenty of options here, with Eurorack‑level gate and pitch inputs, standard MIDI, and USB. As mentioned, the pitch inputs are split for the two oscillators. For convenience, if you only plug into the main oscillator input it actually controls both, but if you connect both they will be pitched separately. As well as being great for shaping sounds that use Osc Mod, this means you can play the synth paraphonically.

The envelopes are ‘conventional’ ADSRs. Majella Audio might have been tempted to consider some control over slope shapes, or the decay slope at least, so you could get a more West Coast dynamic. The 0‑Coast does this, for example, rather than including a low‑pass gate. However, the Implexus envelopes are quite snappy, and the Mod Envelope does have a Loop mode, which effectively turns the attack/decay stage into a triggered LFO. Another bonus is that both envelopes have a built‑in Velocity control.

MIDI is implemented in a tidy and transparent way on the Implexus. You can play the synth from the standard MIDI port or over USB with no setup unless you want to switch from channel 1. The velocity controls on the envelopes make the synth immediately dynamically responsive, and a nice touch is that Mod Wheel (CC 1) is mapped to the Folder. Glide is quite basic: the control simply sets a universal glide time, with no Legato or Auto options.

The synth comes alive when you get stuck into the beautiful control panel and twiddle manually.

Delay

The last piece of the Implexus puzzle is the delay effect. Far from being an afterthought or a bonus, the delay proves to be a seasoning that contributes significantly to the flavour of the Implexus. It’s a digital stereo delay that’s blended with the main signal via another chunky dial. Just like the LFOs, this module has a set of buttons for selecting sync’ed rates, and its own Rate control that takes over when none of the other options are lit. Feedback is introduced with the Regen control.

The delay sounds smooth, and its chief contribution is to add a really nice stereo spaciousness to the sound. Some subtle variation and/or cross modulation is at play. The delay reacts to clock changes with tape‑style pitch gliding. This is a good thing, but can result in some initial wow and flutter from a standing start when running from external clock.

Alright Jack

Twelve Eurorack level patch connections are tucked onto the back panel of Implexus, providing clock connectivity, pitch and gate control and modulation inputs for key sound‑shaping parameters. There are outputs for the Clock, Mod Envelope, LFO 2 and the Basic Oscillator. I was initially puzzled why they would hide the patch points at the back when there appears to be plenty of space at the top left of the panel. I guess this was a design choice to make the main panel as clear and unobstructed as possible. As I had the Implexus standing on one of those Ikea iPad‑cum‑recipe‑book stands it wasn’t a big inconvenience.

The back panel features the expected audio and MIDI I/O, and also sockets for CV and gate.

As well as some of the possibilities we’ve already encountered, Majella offer a few suggestions for fun patches that use the patch points. For example you can get some fun classic modular results by looping the internal clock into the gate, and random LFO to the pitch. Filter FM from the Basic Osc to the cutoff is another obvious and effective trick.

What would have really extended the usefulness of the patch points is if Majella had included a patch‑through attenuator or two, similar to those on the Arturia MiniBrute 2, so you could make internal patch connections with constrained modulation depths.

Conclusion

Sonically the Implexus was quite a surprise. I’d imagined it would be along similar lines to Make Noise’s 0‑Coast, or that the folded and shaped tone source would make it predominantly aggressive or abrasive. It can certainly create edge and bite and produce some vibrant West Coasty plucks, especially when you focus on the Complex Generator, but for me it hits particular sweets spots when you combine all the elements: both oscillators, the filter and delay, and get results more like a classic subtractive synth sound but with a twist of extra harmonic character. In these zones the sound is warm and creamy, and could easily generate a box set of incidental arpeggio cues. While modulation is all targeted at the main tone generation section, the synth comes alive when you get stuck into the beautiful control panel and twiddle manually. Definitely a synth you’ll want to get hands‑on with.