Modal Electronics Cobalt5S

A streamlined version of Modal’s Cobalt8, is the Cobalt5S even better than its sibling?

The Cobalt5S is the slightly simplified 5‑voice, go‑anywhere sibling of the Cobalt8. I say slightly because the differences are minor to the point that it’s almost in competition with itself. While the sound engine is the same, a sense of order and simplicity combined with a less imposing frame gives the 5S every right to stand on its own rubber feet. You could pop it in a bag and take it to Starbucks or your mate’s house without doing your back in or worrying about breaking the joystick off.

The out‑of‑the‑box experience of the Cobalt5S is markedly different to the Cobalt8. While the width is the same, it feels much lighter, with the bulk of the hardware being sucked in from the front and back. The keyboard has shrunk into itself; the back has pulled forward, gathering parameters and merging knobs along the way. It’s a Photoshop‑style exercise in reducing the Cobalt8 down to a more portable and less cluttered format. And it works. It’s still pretty solid, though, with metal front and back plates and a reassuring amount of mass. The encoders float a little like with the Cobalt8, which may feel disconcerting to analogue knob users, but Modal tell me that these are premium quality encoders that’ll last a lifetime of turning.

5S Sounds

As with the Cobalt8, the 5S sounds are just lovely. It’s virtual analogue, so it’s warm and responsive by design. I can’t find a duff preset; nothing clangs or bites, it’s all smooth and joyful, cosy and familiar. While there are some edgier algorithms here, the overall impression is of electronically musical bliss. In trying to find some criticism, you could say that it will be a bit too nice for some people. But if you enjoy smiling, then the Cobalt5S has you covered.

...the 5S sounds are just lovely. It’s virtual analogue, so it’s warm and responsive by design. I can’t find a duff preset...

Modal call the 5S an ‘Extended Virtual Analogue Synthesizer’, meaning that it has more than your regular roster of analogue waveforms. You have two identical oscillators which are really oscillator groups of up to eight oscillators that can run one of 40 algorithms. Each algorithm is like a mini modular patch, where Modal have crafted some exciting waveforms that are folded, modulated and interestingly fiddled with.

Amongst the algorithms, you’ll find oscillator spreads, detuning and pulse‑width modulations; you’ll discover sync and fractals, reverses and ring modulation. There’s quite a bit of ring modulation actually, and then some noise, FM and AM. Each algorithm has two parameters, A and B, that you can play with and modulate. They act as macro controllers for affecting the oscillators. So with the Spread Saw algorithm you can increase the spread with A and detune with B, whereas with Fractal Square, A controls the asymmetry while B handles the sync ratio.

In an initialised patch, it’s fascinating to explore the algorithms, and the little OLED display pulls you into the dance of these waves and how they’re being pulled apart and remade. You can find harshness and sharp edges here; for instance, I created the sound of a truck engine in idle, and then a broken radio transmitter, and then some chiptune noises just by playing in the algorithms of one oscillator. But for the most part, the results are very musical.

Once you’ve enjoyed Osc1 then you have a second one with the same menu of tasty possibilities and a knob that will mix the sound between the two. A favourite feature of mine here is the OscDrift control. This introduces a bit of sloppiness to the tuning and phase of each oscillator. While you can actively detune the oscillators directly, the fine‑tuning controls are a little bit buried in the menu, whereas you can access OscDrift with the tap of the Shift button, and you get a more interesting version of a similar thing.

Control

How do you go about reducing the 29 encoders on the Cobalt8 down to 16 on the Cobalt5S? I imagine you have to decide what’s important and then be ruthless. The result works remarkably well; it’s comfortable, frustration levels are relatively low, and I don’t feel I’m missing out. There’s some initial stumbling about, and the menu system can sometimes feel laborious as these things do. But it doesn’t take long to get the hang of things.

The idea is that you have 16 encoders laid out in a row, with the oscillator controls on the left of the screen and the filter, envelope, effects and sequencing on the right. Each encoder has a default parameter, a Shift function, and a button press. So with the LFO that’s rate and depth, with the oscillators it’s parameter A and B on both and the mix between them. The filter gets cutoff, resonance and morph controls, whereas the envelopes, of which there are three, get a single depth control. The arp and sequencer get division and tempo. The Shift button, which is above the touchpad, then latches on to give you access to the second level of controls, which is where you’ll find things like LFO shape, algorithm selection and ADSR envelope controls.

The envelopes are probably the worst served in this system. You have to be in Shift and have to select whether to control the filter, amp or modulation envelope by pushing down the appropriate knob. On the whole, the parameters you want to use are the most available to you.

However, if menus are a thing you enjoy, then you can access all the parameters on the screen through a combination of the Page and Edit encoders you’ll find on either side. A certain amount of screen time is inevitable, and there’s quite a bit of click, scroll, click the other one, scroll, and so on that is less fluid than I’d like. This is where the MODALApp (see box) starts to ooze with competence, but here’s a pro tip on reducing the annoyance of the menu. By default, whenever you move an encoder, that parameter will replace whatever was on the screen. This can be frustrating if you are trying to get somewhere in the menu to adjust something you can’t do on the front panel. If you momentarily tweak something else the screen instantly leaps to the page for that control and you’ll have to click and scroll your way back to where you were. However, if you dig into the Settings UI & Control page, you’ll find an option to enable Smart Mode on the Screen Switch so that it will drop back to the last page it was on after a couple of seconds. Enable it; trust me, you’ll want to enable it.

Filter

Meanwhile, back in the architecture, the filter section offers a familiar experience that once again feels nice, sounds great and welcomes your explorations. It’s a 4‑pole ladder filter with a morphing function that changes the frequency response. There are four types of filter: a resonant low‑pass and balanced low‑pass, a balanced high‑pass, and a balanced‑phase dual‑notch filter. Filter type is the one filter‑related parameter that didn’t make it to the front panel.

The morphing is interesting because it moves the 4‑pole filter through a band‑pass for the low‑pass and a notch for the high‑pass, and on to a 1‑pole version. It gives you many places to be, bringing in or cutting just the right amount of fizz or bottom end. It’s also an exciting thing to modulate, giving a different vibe to the more common modulation of the cutoff.

Resonance overload or self‑oscillation is not on the cards as this synth is determined to stay in the sweet spot as often as possible, although you do get a bit of a drop off as you boost the resonance. You can make it whistle if you try hard enough.

For its size and price the Cobalt5S is an exceptional synthesizer. It’s musical, engaging and delivers sweet spot after sweet spot of familiar analogue‑style synthesis.

Modulation

The Cobalt5S has the same modulation matrix as the Cobalt8, with four preassigned slots and eight free slots that have a habit of filling up really quickly. You have 11 modulation sources that are selectable from the front panel when holding the Mod button. So to allocate modulators to mod slots simply hold the Mod button and push down on the relevant controller. The screen says it’s awaiting assignment and all you have to do is turn the thing you want to control. The one function that takes a bit of menu poking is the one that clears a modulation slot, and you may have to do this a lot because many of the presets already have ‘All Mod Slots Full’.

There are two LFOs; one is global and the other polyphonic. You’ve got nine shapes, retrigger, free or single modes and speeds from slow to quite fast. There are three envelopes. The first two are tied to the filter and amplifier, and you have to push down on different encoders to select them and then use Shift to access the ADSR controls. The third envelope is all yours to assign to any parameter you wish.

Arp & Sequencing

The arpeggiator is excellent with lots of time divisions and modes in all sorts of directions. Hold or Sustain can be enabled by pressing the Oct+ and Oct‑ buttons simultaneously, which is slightly easier than the two‑handed Shift+button on the Cobalt8. If you hold the arp encoder down, you can design your own arpeggiator by entering up to 32 notes and rests. It’s like a fun, super‑quick sequencer, triggered and transposed when you play a note.

The actual sequencer potentially has room for a massive 512 notes when recording in real time, although in reality, what you have is eight bars into which you can jam in as many notes as you can. Whatever length you’ve set, the sequence will travel through the row of 16 LEDs that sit beneath the knobs. There are a couple of performance controls to loop a section or beat repeat on a section defined by the 16 divisions of your sequence. These are screen‑only features and so not exactly conducive to spontaneous moments of creativity.

You tend to stumble into the four animation lanes as they get assigned and recorded the moment you touch another knob while in record. You can edit the assignment in the menu and also edit or draw in the automation in the MODALApp. You can’t, however, edit the notes in any way. You can overdub more notes, but if you want to change something, you’ll have to clear the sequence and start again. If you switch between step and real‑time modes that will also clear the sequence for you, so be careful not to do that by accident when navigating the menu.

In step mode, the note count drops to 64, but you do get to edit the notes for every step. Step entry is just as you’d expect, and being polyphonic you can add up to five notes per step or enter rests. However, I wasn’t able to find a way to tie notes.

In Edit mode, you get a grid with all five notes on the display that you can cycle through and change the value of. Pressing down on the Preset/Edit knob plays the step to hear the changes. It will also cycle through the animation lanes and let you edit the value at that step. Alternatively, you can edit in real time by hitting record and choosing to overdub and replace notes.

The MODALApp (see box) shows you all the notes in the step sequence in a piano‑roll style and lets you edit and enter new ones. There’s no undo function, so you have to keep your wits about you.

So What’s Different?

The size and shape are the most apparent differences between the two. In the sound engine, you’ve lost three notes of polyphony, the third LFO and the three‑slot multi‑effects engine. On the Cobalt5S you have two fixed effects, delay and chorus. While it’s a shame to have lost the reverb, the chorus is entirely new and excellent. It has a rich quality that brings a good level of enhancement and interest to almost everything you run through it.

You’d probably never be able to tell the difference between the same patch on the 8 and the 5S. But unfortunately, the architecture is different enough for the patches not to be cross‑compatible.

The main thing I’ve noticed in using the two side‑by‑side is that the 5S feels simpler. You’re not as overwhelmed by choice and encoders as you are on the 8. The things you tend to use the most are right there, and in some ways the restricted interface keeps you more focused on those basics. So it’s more accessible, less imposing, and the interface is very clear. Some depth is undoubtedly lost, and having to find some things in the menu system can be a distraction, but the user experience is good and comfortable.

The Cobalt5S’s rear panel features quarter‑inch sockets for headphones, audio out and sustain pedal input, full‑size MIDI I/O ports, 3.5mm sync I/O and a USB‑B port.

The Touchpad

The other key change is that the silver joystick has been replaced by an X/Y touchpad. The pad offers the added benefit of pressure to your manually modulating mix of methods. You can individually assign X+, X‑, Y+, Y‑ and Z to parameters for modulation, giving you five axes of control, although that can use up five of your eight modulation slots. There are alternative modes where you can simplify the touchpad axis or remove the default pitch‑bend assignments and so on to conserve slots.

The original joystick was highly precise, the touchpad feels much less so because you’re dealing with the fudginess of your fingers. This is not a capacitive trackpad like those you’d find on a laptop or a synth such as the Korg Modwave, which detect tiny currents from your fingers and are super‑sensitive; this is a Force Sensing Resistor (FSR) touchpad and so the feel of working with it is a bit different. I found it rather odd to start with. FSR is a technology that allows for the measurement of pressure, and this is what gives us our Z parameter. It consists of a number of layers that are pushed together with your finger so that a conductive film comes into contact with conductive print, and as you push more ink touches the film and lowers the resistance. There is air between these layers, and this gives it a certain ‘feel’, however, I was able to detect what seems like a bubble in one section of the pad which gave an audible crinkly click as I pushed my finger over it. I was able to try a second unit and had a similar experience. Modal were not able to replicate my issue so I can only put it down to my fingers being extra fudgy.

In use, I found that it requires a bit of pressure to activate, and you need to maintain that pressure as you move around, or it will lose its tracking. Then there’s a fine line between giving it enough pressure to activate X and Y and giving it more to activate the Z parameter. It works much faster than a pitch or mod wheel and you can essentially leap to a modulation value without feeling it pass through everything on the way. It’s great for expressive moments and rhythmic accents, and you can easily set it up to control whatever you like. It all works well enough once you get the hang of it and then it becomes a useful and expressive tool to enhance your performance. Although personally I miss the joystick and feel I have plenty enough pressure action with the aftertouch on the keys.

Conclusion

For its size and price the Cobalt5S is an exceptional synthesizer. It’s musical, engaging and delivers sweet spot after sweet spot of familiar analogue‑style synthesis, where it’s really hard to make anything sound bad. The lower voice count is tempered by the smaller keyboard, in that you don’t tend to be playing big, huge pads that span multiple octaves of notes, and so within the context of the instrument, five voices seem like plenty. For a mini‑keyboard, it has a good feel with nicely responsive channel aftertouch.

The size and portability could bring in a lot of new users, and I think its potential to fit into the small MIDI controller space could really increase its usefulness. As very little is lost from the larger Cobalt8, Modal may be in danger of stealing its own customers with this cheaper and more straightforward machine.