ROLI’s Equator2 is less an update than a full rebuild.

Equator2 is a refresh of the original Equator software instrument from ROLI. That first version actually ran natively inside the ROLI Seaboard Grand as well as being available as a soft synth. Equator2 is an update which extends and generalises Equator1, and improves its interface.

Installation is via the ROLI Connect app, the fiddliness of which I think I grumbled about a bit in my review of ROLI’s LUMI keyboard, and installing Equator2 itself is not enough: 5GB of sample library needs to be fetched separately, otherwise most of the presets of this sample‑oriented synth will be silent. You probably want to wheel in the original Equator1 material too — there are some useful single‑cycle waveforms in there, for a start.

Here are a few example presets showing off Equator2's sound capabilities.

First Impressions

Visually, Equator2 has a bit of the Bang & Olufsen about it: grey controls sit against a grey background with very subtle shadows, and a bit of colour is used for sparse (but important) highlighting. Equator2’s window layout is very much a game of two halves: oscillators (or, as Equator2 calls them, ‘sources’), routing and effects share the top half, selectable by tabs, whilst the lower half is completely dedicated to modulation.

Nothing special jumps out from the synth’s rather austere appearance, but it is subtle, deep and layered. For a start, a voice (by which I mean what’s heard when a single key is pressed) comprises six parallel sources, each of which can be configured as a PPG‑style wavetable player, a sample player, a granular source or a noise generator. FM and ring modulation are provided for the synth purists. There are two multimode filters per voice, but each source also has a dedicated filter, making eight in all. Modulation is very well catered for, with five envelopes, five LFOs, two multistep modulation sources and some ‘maths’ functions for side‑band modulation, randomisation and the like. Conventional and MPE gestures can be programmed as modulation, and there’s a macro control panel for broad‑stroke control.

Sound Sources

A central oscilloscope display is flanked by the six panels for the sources, three on each side. Click on a source panel, and the central area switches to a detail view of more controls for that source. Single‑cycle waveform displays are animated — useful to see ‘symmetry’ distortion and wavetable sweeps — but there’s little visual indication for sample or granular playback, or filter shape. In general, Equator2 is pretty miserly with visual feedback, which is a bit of a drawback.

For a source, Wavetable mode really means single‑cycle waveforms of some kind. There are some waves (pulse, sawtooth, sine, square, triangle) which are procedurally generated for maximum accuracy — important for techniques like FM — and a couple of hundred sampled‑based sweepable PPG‑style tables, plus a handful of single‑cycle samples. These can all be shaped by the ‘symmetry’ control, akin to PWM. Waveforms can be stacked and detuned within a single source, leading to the sort of chorusing effects beloved by PPG fans.

Any sources in this mode can participate in FM synthesis: a source can have its frequency modulated by two others. If you want to arrange sources into an FM stack you can mute those intended as modulators, or just not mix them to the outputs. The various FM INIT presets display a clean, crisp FM tonality, even when running with just two or three sine‑wave sources. Other sources could add to the FM or layer it with samples, taking things into classic Yamaha SY territory, especially with some tastefully programmed FM dynamics. For even more harmonic fun, sources can be ring modulated too.

In Sampler mode a source plays samples, as the name suggests. The controls are minimal: apart from the standard pitch, pan and level controls there’s a start offset knob and a switchable 12dB boost, and that’s about it. Most of the named samples are actually multisample sets, but this is only really apparent if you dig around in the file system to find them. Some samples are one‑shot, some are looped: there’s no indication which is which and no display of loop or crossfade points. It probably goes without saying that there’s no actual sampling functionality in the sampler, but you can drag and drop multisample sets on to the sample chooser to add your own into a personal library. Even this modest task might be a challenge depending on your DAW, if it insists on hiding plug‑in windows when backgrounded. (In the end I launched Equator2 as a standalone application when I wanted to add samples that I could use in my DAW.) None of the preset sample sets is fantastically big (the baby grand piano is 340MB, rather small by today’s standards), but the material is varied and decent quality.

Some of the disappointment of the sampler is assuaged by the next source mode, Granular. Pretty much everything you’d expect from a granular synthesizer is here. You can set, and modulate, the starting sample position for the grains, the scan rate through the sample, size and creation rate of grains, grain shape, playback direction, pitch randomisation and stereo width. Rather unusually, grain creation can be quantised to the clock, allowing for rhythmic effects (there are some interesting drum rhythm presets which use this technique). Sample selection works in one of two modes: in ‘note’ mode the multisampling machinery is still in play, so that you get the appropriate sample for the pitch you’re playing. In ‘index’ mode this is switched off, and instead you get to choose which of the samples to use. This isn’t all that useful for the stock acoustic samples, since you’re taking them way out of their natural root pitch, but there are some rather good ‘granular’ sample sets where each sample is a distinct texture. Sweep the index and position with some LFOs and you get some truly dynamic and engaging textures: cleverly, Equator2 lets you dynamically modulate which sample you’re using for grains within a single held note.

The final source type is Noise, with the choice of white, pink or a sparser ‘crackle’. A density control can thin the noise effect out. Noise is not particularly exciting on its own, but for thickening up textures or building drum sounds it does the job.

The voice architecture provides two global multimode filters per voice — each including a tone control — and each source also has a dedicated filter, so that’s eight in total per voice. Unless you’re an avid reader of manuals, you might well not spot them all: the source filter is only shown in the detail view and is disabled by default, visually fading into the grey background.

Routing

Downstream from the six sound sources and the global filters there’s an effects section, but to engage this we have to go into routing mode first, via a tab top‑left, though in fact ‘mixing’ is a more accurate term for what is effectively an audio matrix.

Each of the six sources, and the ring modulation output, has five level knobs for sending signal into the two global filters, two effects chains, and/or directly to the audio outputs. These five levels can be modulated to vary each source’s downstream processing over time, or automated for overall control. The filters can be arranged in parallel or series with various routing options, and their output can be routed into the effects and/or dry to the main output.

The routing matrix is not fantastically complicated but is subtle enough that I found myself wishing for some kind of VU metering to get a sense of what was going where or to explain what I was hearing. (Or why, sometimes, I wasn’t hearing anything at all.)

Effects

Equator2 supports up to 12 effects in a preset — which should be enough for anyone — accessed by a third tab. The available effects are basically the staples (chorus, flanger, filter, gate, distortion/bit‑crushing, EQ, various kinds of delays, a couple of reverbs). There are serial and parallel (six plus six) configurations for the effects block.

The effects controls are pretty plain, and there’s no visual animation or level indication in any of them. Frustratingly, the compressor effect even sports a graphic of a VU dial but no needle to make use of it. So, as ever, you’ll have to use your ears.

Having slightly dissed the effects in general, I’m going to make an honourable mention of the grain delay, which can be pressed into all sorts of textural pitch‑varying services, and the modelled distortion effect which supports a range of algorithms and sounds rich and evocative. Handily, each of the effects algorithms comes with a menu of its own mini‑presets.

Modulation

Equator2 is big on modulation, which is why it devotes half of its window to it. There’s a full modulation matrix behind the scenes, complete with transfer (shaping) functions, macros, mathematics and MPE gestural support.

We’ll start by looking at the visual cues for modulation. Any parameter knob which can be modulated is enclosed by two thin concentric rings. The inner ring shows the current value, which by default will match up with the marker on the knob, while the outer ring shows the extent of the programmed modulation on the parameter. In the nearby screenshot of Strike, the filter cutoff and envelope level knobs show actual values in purple and red respectively; both values are higher than the knob position because the parameters are being modulated by key strike which is highlighted in the centre. The blue of the strike modulator is reflected in the blue outer rings around the knobs. Click a different modulator (they’re colour‑coded in groups) and the outer rings will update to show that modulator’s influence. Click and drag the outer ring area to change the modulation amount; the inner ring will update in response.

As is usual, some modulation sources are per‑voice (envelopes, LFOs and MPE gestures), others are for the entire preset (macros, conventional MIDI controls like mod wheel). Per‑voice modulation sources can be applied to preset‑level effects parameters — there’s a setting to specify which voice supplies the modulation, or you can apply an average of all sounding voices.

For a more detailed view, you can right‑click a modulator’s title tab to see a table of the controls it is attached to, together with amounts and transfer functions — entries can be added, edited and deleted here. Right‑click on a control knob and you can see all the modulation sources which affect it. You can also pull up a global mod matrix table for the entire preset.

Looking at the modulators themselves, there are five identical envelopes, although the first ‘AMP ENV’ by convention controls voice allocation. Envelope modes include ‘ADADR’ which loops the attack‑decay portion while a note is held, and ‘ADS‑PR’, which provides a pluck‑release section on note‑off. (The attack decay is still present, so there seems to be no way to make an envelope ‘pluck only’, as it were.) Most segments have adjustable curves. Segment times range from sub‑millisecond (at least according to the control readout) to 32 seconds maximum, and there’s a sync mode to use metrical times including dotted and triplet values.

There are five general‑purpose LFOs with multiple waveforms, and two ‘multi‑mod’ units which are essentially loopable grid‑based envelopes, the closest thing Equator2 has to a step sequencer. Once again, I found myself wishing for a bit of live visual feedback here: it would be good to see the current playback position of a multi‑mod (per voice, ideally), especially since the playback rate can be modulated, and multi‑mods can free‑run without notes being held. As ever, you’ll have to use your ears.

Also in the modulation arsenal is keytracking — again editable as a multistage curve. Unless you click on a tiny icon (or read the manual!) you may completely miss the fact that there are four independent keytracking sources. Keytracking is not applied to a parameter directly as a modulator: instead it influences the other modulators already on that parameter, by shifting, limiting or scaling their effect.

A collection of math modulators take one, or two, input modulation sources and process them in some manner: lag, quantise, add, multiply, threshold, etc. In the same group is a set of random sources which are sampled at note‑on, and a ‘flip‑flop’ which alternates between minimum and maximum on each played note.

Last, but by no means least, we come to the performance modulators associated with keyboard gestures, dominating the lower centre of the window. Equator2 believes in two kinds of keyboard controller: those which support MPE, and standard ones which don’t. Every preset is either configured for MPE or not. In MPE mode the five modulators are for the so‑called ‘five dimensions’ of gesture (strike, glide, slide, press, lift), available as per‑voice modulation sources. Switch to standard mode and the modulators switch to their traditional equivalents (velocity, pitch‑bend, mod wheel, etc).

The rest of the preset isn’t directly aware of whether modulation is coming from the MPE sources or not: switch to standard and mod wheel will have much the same affect as slide, albeit monophonically. This led me to wonder why Equator2 ships with many of its presets essentially duplicated, with a standard and an MPE version of each. According to ROLI, there are enough articulation differences between MPE and standard presets, even for the ‘same’ sound, that it makes sense to customise them.

As with keytracking, each of the five types of performance modulation is available as four distinct sources, with individual editable response curves. There’s a selection of preset curves and new ones can be saved into a library.

Wrapping up the tour of modulation sources we have five macro controls, which just so happen to resemble the five left‑hand controllers on a ROLI Seaboard. You don’t need to own a Seaboard to make use of them: they are MIDI‑mapped, and you can automate them from your DAW. Two of the five controls are presented as X and Y axes on a grid — mimicking the Seaboard hardware — which led me to reflect on how useful it might have been to have more X‑Y controls inside Equator2, especially for the routing and mixing of the six sound sources into the filters and effects. As a Korg Wavestation fan, perhaps I just want to vector‑mix everything.

Equator2 Sounds

Equator2 comes with a shade under 1500 presets, of which about 40 percent are MPE‑capable, plus 360 legacy presets from Equator1. In addition, ROLI are putting out paid‑for soundpacks, as first seen in their Studio Player. Since I own Equator1 and Studio Player, the compatible soundpacks from both products appeared inside Equator2. As I write, four new Equator2 packs are available for purchase and download, and by the time you read this a free pack called Motion Waves should be part of the Equator2 bundle.

There’s a fair range of good‑sounding material on offer, more than I have space to describe here. Good use is made of Equator2’s modulation features, with a few rhythmic patterns that would fool you into thinking that you had some kind of arpeggiator on board. I was not that taken with vintage synth and SynthWave sounds, but only because my personal philosophy is that you’re better off crafting material like that for yourself. Orchestral fare is pretty thin on the ground, too. On the other hand, the cinematic soundscapes and ‘action sequence’ presets sound contemporary, rich and expressive. It’s the MPE presets which really shine in terms of expressiveness and control, so if you’re a soundtrack maker you should think about investing in a Lightpad or Seaboard Block as an input device.

Conclusion

I’m going to come clean and confess that I was initially slightly biased against Equator2. I can have a bit of an issue with sample‑based synths in general, probably dating back to my days with a Korg M1, and my personal take on the original Equator version 1 is that it was tailored to making a Seaboard sound good — which it does! — rather than being a fully rounded instrument in its own right.

If you have a ROLI Seaboard or Lightpad I’d say it’s a no‑brainer; even if not I strongly recommend it.

With Equator2, it’s clear that there’s been a rethink of the design to make it more rounded: six general‑purpose sources per voice, granular synthesis (which will always win me over to a sampler‑player), powerful audio routing, lashings of effects and a top‑notch modulation system. It is only let down slightly by the feature‑challenged sample player. Visually the controls are perhaps a little too understated — it’s a bit hard to see what’s enabled and what’s not at a glance — and such a powerful device would benefit from more animated feedback of audio levels and real‑time modulation. But overall there are no sharp edges or gotchas, accessibility is good given the complexity of the device, and it sounds great. If you have a ROLI Seaboard or Lightpad I’d say it’s a no‑brainer; even if not I strongly recommend it.