Union Audio four.valve Signature
Some mixers announce themselves immediately. LEDs, features, a sense of urgency to be noticed. The Union Audio four.valve Signature does the opposite. It settles in quietly, lets the room breathe, and then, a few blends later, you realise you are hearing differently. Not louder. Not brighter. Just clearer, deeper, more honest.
Union Audio is based in Cornwall, UK, far from the noise of trend cycles, which feels appropriate. Founded in 2014 by Andy Rigby-Jones, one of the architects behind the modern DJ mixer and the mind that shaped the Xone lineage, the company was built around a principle that feels almost unfashionable now. Sound first. Always. Before features. Before software. Before marketing language.
Over the years, Union Audio has collaborated with names that actually carry weight in this conversation. Richie Hawtin’s PlayDifferently, MasterSounds Audio, TPI. Projects where listening mattered more than novelty. Alongside those collaborations, the company has quietly developed its own line of mixers, not as statements, but as tools. Built to be moved. Built to survive real booths. Built to stay consistent when the room stops being forgiving.
The four.valve Signature is the clearest expression of that mindset. Part of the Signature Series, it is a hand-assembled evolution of the valve.series, designed for DJs who care about how sound behaves over time, not just how it hits in the first track. Each channel runs through its own valve stage, adding second-order harmonics and a natural, musical compression when pushed. Not distortion. Not colour for effect. More like tension and release inside the sound itself.
What stands out is discipline. This mixer does not smear the signal or lean into exaggerated warmth. It keeps its balance. Headroom feels generous. Transitions feel calmer. Long mixes remain articulate instead of collapsing into density. On a properly tuned system, especially in a big room, the low end feels round without losing grip, the mids stay confident, and the highs never turn brittle. Vinyl sounds precise and alive, thanks to carefully tuned phono stages, but digital and hybrid setups feel just as resolved.
Union Audio understands something many manufacturers seem to forget. A mixer should not compete with the DJ. It should disappear. The four.valve Signature is laid out with that philosophy baked in. No clutter. No unnecessary distractions. The heavily damped rotary fader, taken from the Orbit.6, encourages patience and control. The three-band EQ is musical, forgiving, usable across long blends. The Innofader crossfader is there when you want it, invisible when you do not.
Physically, it feels like an instrument, not a product launch. Solid metal chassis. Precisely machined aluminium. Wooden side panels that add warmth without pretending to be vintage. Everything feels considered, not decorative. This is gear designed to age well, not to be replaced next season.
Most DJs know the truth by now. Half the features on modern mixers rarely get touched, especially deep into a night. The four.valve Signature feels like a reset. A reminder that what really matters is how sound fills space, how it carries emotion, how it holds together over hours, not minutes.
No hype. No flashing distractions. No performative technology. Just serious analogue sound, built with intention, and meant to move effortlessly between studio sessions, demanding clubs, and booths where listening is the real skill.
The Union Audio four.valve Signature does not ask for attention. It rewards it. And once you spend real time with it, it becomes very difficult to accept anything that tries harder and says less.
