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Novation Circuit Mono Station

Sequenced Paraphonic Analogue Synthesizer
Published August 2017
By Simon Sherbourne

Novation Circuit Mono Station

Could a mash-up of Novation’s Circuit and Bass Station II with a pinch of modular connectivity be the perfect recipe for the modern monosynth?

Novation’s original Circuit is an all-in-one musical sketchpad, which marries a pad grid controller with two polyphonic digital synths and a four-part drum machine. I bought one to use as a portable groovebox to noodle with around the house, but ended up mainly using it with other gear and software because of its brilliantly fast hands-on sequencing system. More recently my Circuit has been in almost permanent service as a modular synth sequencer via the MIDI to CV converters on my Make Noise 0-Coast synth. When I saw that the new variant had an on-board analogue synth and modular-friendly CV, Gate and Clock connections I figured I wasn’t the only one thinking this way (and I was more than a little covetous).

Integrated Circuit

The Circuit Mono Station has a simple concept: combine the performance and sequencing side of the Circuit with an analogue monosynth, and add some scope for integration into a larger synth setup. All of this could be divined simply by looking at the unit. The bottom half of the panel is mostly the same as the original Circuit, with some of the pads redefined for different functions. The top half houses the generously appointed synth control section, which makes the Mono Station 5cm larger front to back. The Mono Station is also a bit thicker, making it stand proud of the classic Circuit when they sit side by side.

Like the Circuit, the Mono Station requires too much juice to be USB-powered, and in this case can’t use batteries either, so the AC adaptor is a permanent fixture. There’s also no built-in speaker, so the Circuit remains the truly mobile Novation workstation, though the Mono Station is super-portable by anyone else’s standards.

The Mono Station shares most of its basic operational concepts with the vanilla Circuit, utilising the pad grid in various modes or views for performance and sequencing, pattern triggering, project management, etc. This allowed me to plug in some headphones and get a sequence going with barely time for the eagerly discarded packaging to hit the floor. I couldn’t help noticing that the headphone port exhibited quite a bit of noise, including a faint bleed from the oscillators. This is not an issue with the main output, which is a single quarter-inch TRS socket compatible with either balanced or unbalanced inputs. The output is (thankfully) mono. It might have been tempting to stereo-ise the output with showroom-friendly chorus or delay effects, but that would have over-egged and cheapened a perfectly tasty pudding.

The pudding in question is the Bass Station II. I’m guessing nearly every SOS reader has at some point played with, if not owned, a Bass Station in one of its incarnations. It’s a versatile and sweet sounding monosynth. The version in the Mono Station is mostly a full transplant of the Bass Station II; the most obvious compromises are the loss of one envelope generator and one LFO, but there are also several enhancements such as a new distortion mode and expanded mixer. And then of course there’s this intriguing paraphonic business...

Split Personality

The original Circuit has two note/gate sequencers, one for each of its internal Nova synths. The Mono Station has just one synth but has kept both of the sequencers. Tapping the Osc 1 button brings up the first sequencer on the pads, presenting you with two octaves within the project’s scale, and 16 steps representing a Pattern. Notes are entered into a Pattern by holding a step and selecting a note, or by real-time recording. (As with the Circuit, there’s no on-board click, so if you’re working stand-alone it’s tricky to start off with real-time recording). Velocity is captured when recording live, but not via step entry (which would have been nice as an option). Dedicated velocity and gate length views are provided for adjusting these parameters on existing notes.

The Osc 1 sequence plays the synth as a whole, pitching the dual oscillators, gating the VCA and triggering the envelope; in other words business as usual for the Bass Station or any typical monosynth. But the Mono Station can use the Osc 2 sequencer to control the pitch of the second oscillator independently of the first. (MIDI channels 1 and 2 can also be used to play the Mono Station). So you have two semi-independent oscillators, with a single voice path through the VCA and filter: not truly polyphonic, but paraphonic.

There are two different paraphonic modes. In the default Mode 1, only the Osc 1 sequence (or MIDI channel 1) triggers the VCA/envelope. In this mode anything happening in an Osc 2 sequence will only be heard while notes are sounding from the other sequence. In Mode 2, notes from both sequences act as gates. If you’ve spent time patching stuff together in Reaktor, Reason or a hardware modular you’ve likely hit upon this architecture before, but it’s sufficiently unusual to need time to get your head around. Handily there’s a Dual mode view that lets you play both oscillators from the pads at the same time, and a bit of experimentation here helps to understand what’s going on. The important bit to grasp is that triggering a gate from either side effectively ‘plays’ both oscillators, it’s only when there are two different notes held at the same time that the pitches diverge.

The results can be really pleasing, and often unexpected. You can add varying chords, harmonics, drones or top lines to a sequence, and get instant chip tune-ness if that’s your thing. Other interesting possibilities emerge when you experiment with using dual note sequences alongside oscillator sync or ring mod. In these cases pitch variations between the oscillators alter the timbre, giving some really dynamic results.

Synth Bassics

We’ve maybe jumped in at the deep end a bit by focusing on what’s new. The synth has twin multi-mode oscillators with sine, triangle, saw and variable-width pulse wave shapes. There’s also a fixed-mode sub that tracks Osc 1, and a noise generator. Ring mod between the two oscillators is available as an independent source, and oscillator sync extends the sound palette further. The filter uses the Bass Station II’s ‘Classic’ mode design with the same great overdrive control for instant fatness. Perhaps as consolation for losing the ‘Acid’ filter, a second flavour has been added to the distortion stage, where you can select either type or both at once.

As a synth the Mono Station is just as straightforward and usable as the Bass Station; more so in fact. The Circuit had a great innovation that proves even more valuable here. Every pot and slider has an LED which indicates its current value with brightness. This is a godsend on an analogue synth with patch memory and project recall, giving you a good visual clue of the current settings even when the physical controls are out of sync with reality. On top of this you can choose whether the pots act instantly or pick up from new values after a patch change. Where the Bass Station II mixer section shares a pot for three of its sources, here all six have their own clear mini pots which light up progressively to show the levels. As well as selecting sequences, the Osc 1 and 2 buttons toggle shared synth controls between the two, using colour-coding on the relevant LEDs and backlit pads.

The Circuit Mono Station’s main panel measures 240 x 250 mm.The Circuit Mono Station’s main panel measures 240 x 250 mm.Panel space is saved by replacing dedicated modulation depth controls with a single mod matrix. This is a set of buttons for targeting modulation sources and destinations, with a single bipolar Depth knob. The loss of one envelope and LFO is made up for by a dedicated modulation sequencer, giving you eight 16-step patterns controlled from the pads, with optional smoothing. What’s more, every parameter can be automated within each pattern, either in real time or with per-step snapshots. Sweet Christmas!

Work Station

The Circuit’s sequencing system is what sold me on the first box. It bases everything around 16-step patterns which are selected and launched from a dedicated grid view. On the Mono Station, the Osc 1 sequencer gets 16 patterns slots, while Osc 2 and the Mod Seq get eight each. Patterns can be launched individually, or in chains as a looped range by tapping two pads. As the three sequences all interact with each other in the Mono Station synth, combining different patterns provides instant variety. You can also change a pattern’s length, speed and direction (forward, backward, ping-pong, random) on the fly. New to the Mono Station is Mutate, a function that alters the current pattern in a semi-random way. Given this wealth of features I feel slightly spoilt saying that I missed the pattern Nudge feature from Circuit.

The single pattern launch page does not represent a hard limit to your song or set structure, as you can simply start a new Session, or duplicate your current one. Sessions can be recalled smoothly during playback, in which case the new Session keeps the tempo of the previous one. By default, Session changes are quantised to the bar, but with the addition of the Shift button you can trigger a Session instantly, maintaining the same place in the bar. And one of the best things about Circuit’s all-in-one-box approach is that projects store both the Sequences and the synth settings, so spilling a song across Session slots lets you recall different patch snapshots in each.


Novation have spliced the performance and sequencing elements of the original Circuit with the Bass Station II monosynth sound engine. But this isn’t a crude cut-and-shut: each side of the equation has been carefully re-worked to suit the new form factor and workflow. Dual oscillator pitching, a modulation sequencer and on-board automation give the Bass Station engine a new lease of life. It was already a great sounding synth, with a lovely filter overdrive that can be warm and smooth or squawk and self-oscillate with the best of them.

CV, Gate and Clock connections, along with the audio input, make the Mono Station a useful contributor in your wider synth setup or modular, triggering and patching in external voices, or doubling as a versatile modulation source, signal processor, a monophonic sequencer and even MIDI/CV convertor. As a general purpose sequencer the original Circuit still has the edge, though, with it’s two independent polyphonic sequencers and drum triggers, albeit confined to MIDI.

All in all the Circuit Mono Station is a unique, powerful and rather lovable little beast that embodies the fusion of old and new technologies that is making synth hardware so exciting right now.


I’m pretty confident that a combined pad grid sequencer, performance controller and analogue synth is a unique proposition. There are other monosynths with some sequencing capabilities and analogue connectivity worth a look, including Arturia’s MiniBrute and MicroBrute, or Korg’s Monologue. Alternatively a BeatStep Pro with another synth like the Dreadbox Erebus (also paraphonic) would give you more modular connectivity. But none of these other synth options have patch memory, not to mention integrated project recall and song/set-level sequencing capabilities. Just as this review was going to press, Roland announced the Minimoog-inspired SE-02, which includes on-board sequencing, so this may also be worth considering.

Mono Station Integration

My original Circuit has proved particularly useful combined with other gear, so I was keen to see what was possible with the extended connectivity on the rear panel: MIDI, CV, Gate and Clock, plus an audio input. Straightforward sync is well taken care of, with the Mono Station able to chase and generate MIDI Clock or analogue clock pulses. The latter take precedence if present. Both the main sequences can output (and capture) via MIDI on separate, user-definable channels. Every synth control on the panel generates and responds to MIDI CC, making it easy to record automation to a DAW as well as the internal sequences. This did cause me some problems with another synth I was controlling which kept getting its setting screwed up by these messages, but luckily you can turn CC transmission off if necessary.

At the back of the Circuit Mono Station we find a  socket for the 12V power supply, a  USB-B port, 3.5mm sockets for CV, Gate, Clock and MIDI I/O, and a  pair of quarter-inch jacks for audio in and out.At the back of the Circuit Mono Station we find a socket for the 12V power supply, a USB-B port, 3.5mm sockets for CV, Gate, Clock and MIDI I/O, and a pair of quarter-inch jacks for audio in and out.

To test the analogue connectivity I hooked up the CV and Gate outputs to my 0-Coast semi-modular, benching the original Circuit that had been sequencing it via MIDI. Gates are sourced from the Osc 1 sequence (and Osc 2 if in Paraphonic 2 mode), while CV is derived directly from the pitch of Osc 1. This means any pitch settings and modulation in the current patch that affect Osc 1 also affect the CV out. I hadn’t quite expected this, but it proved quite useful being able to modulate both CV outputs. I did encounter a fundamental problem where 16th note gates are always tied, as though the gate length can’t go shorter than this, but I’ve been assured that this will be addressed by the time the Mono Station ships. Another slight gripe was that because the Volts-per-octave is mapped as 0V=C1, sequences with notes below this flatline as far as CV is concerned, and I couldn’t get my VCOs as low as when connecting the MIDI out.

The fact that only one of the sequence tracks is available as CV, and it’s the same as the one that drives the internal synth, means it’s not quite the all-in-one BeatStep replacement I’d secretly hoped for, but there are some compelling uses. The Aux CV output lets the Mono Station act as a very versatile modulation source in a modular setup. The Aux CV is a destination in the Mod Matrix, so any of the sources (Envelope, LFO, Velocity, and the Mod Sequence) can be scaled and mixed together as an output voltage. But the most fun I had was simply routing the audio from my external synth back into the Mono Station, using it as an extra audio source to blend with the on-board oscillators.

Component Upgrades

Back-up and loading of project and patch banks is handled by Components, available as a web interface or stand-alone app.Back-up and loading of project and patch banks is handled by Components, available as a web interface or stand-alone app.The original Circuit has benefited from continuous updates since its release, many of which have been inherited by the Mono Station. One of these is Components: a librarian (also used by Peak) that stores your projects, patches and samples in the cloud and is accessed via a web browser, or a stand-alone app if you prefer to keep your stuff local. On the Mono Station, Components lets you manage Sessions and Patches in banks of 32 and 64 respectively. You can colour-code Sessions, which is really helpful for visually grouping multiple Sessions when constructing a song or set.

Components is also the vehicle for firmware updates: by the time you read this the Mono Station should be at v1.1, which already improves on my test version with fixes and useful features such as a much-needed shortcut to reset Mod Depth values to zero. The original Circuit has now reached 1.5, with each dot release adding significant functionality. Nearly everything on my personal wishlist from my original review has been delivered, including drum sample and synth patch auditioning, Session back-up, a software synth editor and per-step sample swapping. Other features that have also made it into the Mono Station are instant Pattern switching and the ability to record into the sequences from external MIDI sources.

Published August 2017