Rega’s only preamplifier, in detail. The Mercury’s specifications are set out below.

The Mercury is Rega’s flagship preamplifier, and by some distance the most ambitious piece of electronics the company has built. Rega describes it and the matching Solis power amplifier as the culmination of almost four decades of solid-state amplifier development, and traces the Mercury’s circuit lineage back to the original Elicit of around 1990. The names are deliberate: Solis is Latin for sun, the power amplifier as the energy source, and Mercury the planet closest to it. It is a preamplifier built around one idea above all, an ultra-low noise floor, on the reasoning that quiet passages contain as much music as loud ones, and that anything a preamplifier adds is detail the listener loses.

Brief product overview

A reference preamplifier using a discrete, fully symmetrical amplifier circuit throughout, engineered for the lowest possible noise floor and correspondingly wide dynamic range. Rega calls it the most electronically complex product it has made. Several elements are drawn from elsewhere in the range: the volume control is the same as the one used in the Osiris integrated amplifier, and the built-in DAC derives from the stage used in the Saturn Mk3 and flagship Isis CD players, so digital sources can be connected directly. There is a discrete headphone amplifier that Rega likens to a miniature Solis for its voltage and current delivery, rated at 9 volts and 2.5 watts into 32 ohms and 10.85 volts into 240 ohms, both at 0.1 percent distortion, so it drives demanding headphones properly. A full-colour IPS display handles system information, and a custom backlit Orbit remote wakes on a motion sensor. Connectivity includes balanced and unbalanced inputs and outputs. There is no phono stage; Rega intends the Mercury to partner its Aura phono stage. The chassis measures 435 x 97 x 380mm and weighs 14kg, closer to a compact power amplifier than a typical preamplifier, and it is built in England.

How it sounds

The Mercury’s defining quality is silence, and what that silence reveals. With the noise floor pushed as low as it is, quiet detail that normally sits just below audibility becomes plainly audible, which gives the presentation its sense of dynamic range and its unforced energy. Reviewers have described the Mercury and Solis pairing as wide open, rhythmically propulsive and full of life rather than merely clean, which is the balance Rega has always chased and here achieves at a level the company has not reached before. The onboard DAC is a genuine asset rather than a convenience, drawn as it is from Rega’s best CD players, and it means a network transport can feed the preamplifier directly. Being purely analogue in its amplification, the Mercury takes its character from the sources and the power amplifier around it, adding clarity and control rather than a signature of its own.

What we’d partner it with

The Mercury is a preamplifier, so it needs a power amplifier, speakers and sources. For power, the natural partner is the Rega Solis, designed alongside it and sharing its fully discrete, fully symmetrical topology with differential drive throughout: 168 watts per channel into 8 ohms and 305 into 4, with balanced and unbalanced inputs. The Mercury also works with the Aethos power amplifier if you would rather a smaller system.

For speakers, we suggest the Monitor Audio Platinum 200 3G, a compact three-way floorstander using the MPD III high-frequency transducer, a 4-inch RDT III midrange and twin 6-inch RDT III bass drivers. It is 88dB sensitive with a 4-ohm nominal impedance and asks for 150 to 600 watts, which is precisely why the Solis suits it: 305 watts into 4 ohms gives it the current and control it needs. Good alternatives from brands we carry are floorstanders from Fyne Audio, Sonus faber, Dali and Wharfedale.

For vinyl, the Mercury has no phono stage, so a turntable connects through an external one. We suggest the Rega Naia fitted with the Aphelion 2 moving-coil cartridge, through Rega’s reference Aura phono stage, which is the combination Rega itself puts forward as the complete reference system. The Aos MC is the more affordable route to much of the same performance if you would rather.

For digital, the Mercury’s own DAC is well worth using, so a transport rather than a full streamer makes sense. We suggest the Aurender N20, a network transport with no converter of its own, whose AES/EBU, coaxial, BNC, optical and isolated USB outputs are governed by an OCXO clock for very low jitter. It feeds the Mercury’s DAC directly, which is exactly the arrangement both components were designed for.

On cabling, run the preamplifier to the power amplifier on balanced cables where you can, and use a well-made speaker cable of appropriate gauge for the run; AudioQuest and Chord are the cable brands we stock.

Who shouldn’t buy it

If you want a single box, the Osiris and Aethos integrated amplifiers give you preamplifier and power in one chassis for considerably less, though without the separation that isolating low-voltage circuitry from high-current sections provides. If you need a phono stage built in, the Mercury has none, so budget for the Aura or Aos alongside it. And if your system is not at a level to reveal what a preamplifier of this class offers, the money is better spent on speakers or on the source.

The Mercury is a substantial component at 14kg and wants proper shelf space and ventilation. Run it to the Solis on balanced cables where you can; Rega supplies a pair of interconnects and power cords with the amplifiers, which is unusual at this level and worth knowing. For vinyl, connect the Naia to the phono stage and the phono stage to a line input; as a Rega turntable it earths through the phono lead. For digital, connect the Aurender N20 to one of the Mercury’s digital inputs, since the N20 is a transport with no converter of its own and the Mercury’s DAC does the work. Place the Platinum 200 3G clear of the rear wall and level it carefully. The IPS display can be adjusted, and the Orbit remote’s backlight wakes on movement.