GS Music Bree6 Keyboard

The new version of GS Music’s Bree6 has gained more than just a keyboard...

When I reviewed the original GS Music Bree6 back in September of 2025, I concluded that the compact desktop synth was lovingly designed, excellently made and sounded great; but also that, given its consequent price tag, it might struggle to break into an increasingly competitive market for small‑footprint hardware synths. This was in small part due to it having no keyboard to speak of, an absence that might not matter to some, but could inadvertently give comparative — and cheaper — keyboarded units such as the Sequential Fourm and the Moog Messenger the edge.

It seems that GS Music, the Buenos Aires‑based company founded by Guido Salaya (whose e7 is slated as the first analogue polyphonic synth to be designed and assembled in Argentina), have cottoned on to this, delivering a freshly keyboard‑endowed Bree6 model. This edition of the synth is essentially still simply named the Bree6, with the manual cover showing images of both versions, though it is referred to within as the Bree6 Keyboard. With a clutch of performance‑related mod cons beyond the simple addition of keys, this iteration of the Bree6 promises an all‑in‑one, bigger‑but‑still‑portable package that in many ways serves to justify the existence of its desktop sibling. In fact, it occurs to me that most of the time two such iterations of synthesizers actually appear in the opposite order, with desktop versions tending to be released after their keyboard counterparts. While we’re on the subject, I’ll say that one notable exception is Elektron’s Digitone Keys, which is a good example of just how much difference to the perception of unit a keyboard can make; what with Elektron’s transport‑based playability occupying the limelight for its products most of the time.

What’s What

A recap on the original Bree6’s architecture, which, in case it wasn’t clear, is present and unabridged in the Keyboard version. A six‑voice polyphonic synth, it comprises a stripped‑back set of features to pack a real punch. The desktop version measures a diminutive 360mm in length, 126mm across and just under 70mm deep, and — as previously noted — its build quality is a standout feature; with firm, solidly mounted knobs and buttons, a sharp OLED screen and rugged metal chassis coming together to weigh a reassuring 1.5kg.

With a fully analogue signal path, each voice offers a single oscillator with sawtooth or square waveforms and a per‑voice square‑wave sub‑oscillator. Its four‑pole low‑pass ladder filter of course takes its cues from Moog, and there’s a solitary LFO and two ADSR envelopes. So far so solid, and I have to say — as I did before — that despite a modest feature set that hardly sets out to reinvent synthesis as we know it, at what it’s attempting the Bree6’s core architecture can’t really be faulted. It’s a stripped‑down ‘mini‑Minimoog’ of sorts, that does a good job of outsourcing all manner of other features to provide a no‑nonsense piece of hardware that I have no doubt will stand the test of time in any studio or portable setup.

As far as its more distinguishable attributes go, the Bree6 also hosts an onboard OLED screen. As GS Music are rightly proud to proclaim, there is little to no menu‑diving here, and it does a good job of presenting clear and handy graphics whenever a parameter is changed; be it simple, bold number values, envelope shapes or the filter cutoff.

The Bree6 offers a pair of lush‑sounding onboard digital effects in the form of chorus and delay. These are remarkably good, and blend into the sound‑sculpting workflow of the thing brilliantly, with the delay reaching short enough times to emulate pinging, ring‑mod‑reminiscent sounds, and the chorus playing nicely in tandem with the oscillator Detune parameter. There’s generous space for 512 presets and a decent package of I/O, with both USB and DIN MIDI (in, out and thru) supported, discrete left and right outputs and a TRS headphones output. Finally, at least for the headline features (head back to my review of the original Bree6 for a more in‑depth rundown), there’s support for MPE control across both iterations of the Bree6, with menu‑configurable relationships between a controller’s pressure and Y axis and the synth’s VCA and VCF.

What’s New

Fair to say that having set such a precedent, it would be incongruous of this edition of the Bree6 to start cutting corners. This time its physical size doesn’t so much belie its hefty sound as connote it, measuring 550mm in length, just under 300mm across and just under 120mm deep, bringing its overall weight to a relatively beefy 6.25kg. The build quality is equally good here — better, in fact, with rather lovely wooden cheeks complementing a bright blue chassis and of course the black and white keys to give the thing a classic, veritably gorgeous colour palette. Should that palette be too much, though, I should point out that the Bree6 Keyboard is also available in black.

In addition to the USB‑B port, MIDI in, out and thru sockets, and quarter‑inch audio and headphone outputs found on the desktop Bree6, the Keyboard version has gained quarter‑inch inputs for a footswitch and expression pedal.

Happily, the keyboard’s 37 full‑size keys offer a very pleasant action and a great‑feeling keybed. It’s velocity‑sensitive and has aftertouch, which — and this is not a given, even with expensive synths — is smooth and even in its action. The modulation and pitch wheels are laid out above the keyboard as opposed to beside it, which I personally tend to prefer since it feels like a better use of overall space. Once again these are firm and solid to the touch, and usefully the modulation wheel can have its relationships with the oscillator modulation and filter cutoff adjusted in the quick‑to‑access Control menu. It’s also worth giving an honourable mention to the additional I/O here, namely an expression pedal input and momentary footswitch (that is, usually a sustain pedal) input. All this, along with the Bree6’s MPE support, comes together to provide more or less the complete performance feature set, and I’m glad to see it done so well.

What’s More

I mentioned earlier that this edition of the Bree6 adds more than just a keyboard to the desktop version. Indeed, a new section has appeared on the panel offering controls for an arpeggiator and sequencer. As with many of the Bree6’s features, these aren’t showstoppers on their own but make worthy contributions to a very effective and cohesive piece of synth design. The relationship between such functions and the Bree6’s well‑deployed delay effect can be used to create syncopated patterns that feel like far, far more than the sum of their parts, and are more or less faultless in their capacity to get the job done. The arpeggiator offers up, down, up/down or random orders, along with a wide tempo range of 40 to 240 bpm and divisions of 1/4, 1/8, 1/16 or 1/32 notes. If there was one notable function here it’s the Double and Triple modes button, which groups multiple consecutive notes in twos or threes within each arpeggiator step to ostensibly provide a different, more complex musical behaviour when shifting between chord shapes.

The sequencer is even more quick and intuitive — and lengthy if desired, with up to 400 notes allowed: just hit Record, play a succession of notes (including rests, with a dedicated button) and then hit Play. The screen displays a useful MIDI piano‑roll‑like graphic when inputting note data, and it’s polyphonic, so chords can be sequenced as well. For the cherry on top, you can save and recall sequences, which is mighty useful for live performance.

It feels like this edition of the synth is in fact the essential one, opening up its functionality in more powerful ways than ever and cementing the Bree6’s standing as a top‑notch instrument...

Conclusion

I went into this review thinking that the addition of a keyboard would be of relatively little consequence for the Bree6. On the contrary, it feels like this edition of the synth is in fact the essential one, opening up its functionality in more powerful ways than ever and cementing the Bree6’s standing as a top‑notch instrument — as well as its designer’s as a developer to be reckoned with. The original’s price tag of just under £1000$1000 felt steep, this edition’s relatively modest increase, to £1467$1699, contrastingly delivers what is really excellent value for money. A very good move from Guido Salaya and co.