Auris Audio

Euterpe Valve Headphone Amplifier

£1,499

Auris Audio's head honcho Miki Trosic is one of those people who refuses to stand still, even for a moment. Look through the Serbian brand's product catalogue, and you'll find an array of equipment that spans valve powered integrated amplifiers, preamps, monoblock power amps, solid-state DACs, and loudspeakers. Then there's the recently announced Tangenta Hawk tonearm, with a turntable that should be following it soon. And don't forget the EarMen head-fi brand's formation that focuses on portable DAC/headphone amplifiers. However, it's a tube-based headphone amp that I'm here to talk about today, called the Euterpe.

UP CLOSE

Named after one of the nine muses in Greek mythology – the goddess of music and “giver of delight” – the Euterpe was released in 2019. It cuts a defiant silhouette, especially compared to the manufacturer's other offerings, such as the squarer HA-2SF that sits just above it in the company's head amp hierarchy. Fitted with an ECC81 input tube and two PL95 valves with the option to fit EL95s (there's also a selector switch should you choose that route), the unit stands 280mm tall with width and depth of 160mm and 30mm, respectively.

The matt black aluminium central unit contains the valve amplification and an ESS Sabre ES9018 DAC, letting you connect your computer via the rear USB B port and have the Euterpe decode DSD128 and PCM up to 32-bit/384kHz resolution. That's not quite bleeding edge, but it's good enough for most of us. Those needing more can, of course, run their choice of DAC between the source and the amplification stage – the latter being the Euterpe's main event, after all. Joining that digital input is a pair of RCA phono sockets, each for line-level source and line output.

The Euterpe's fascia is dominated by a large volume dial which also takes care of switching the unit on and off. For those like me who lack the patience that valve amplifiers require, it only takes a minute or so to warm-up from a cold start. Two toggle switches cover source selection and the option for high (150+ ohms) or low (32-80 ohms) impedance. All of this is sandwiched between two sizeable pieces of solid wood, braced at the top by metal rods which also serve to protect the vacuum tubes.

Additionally, this lofty wooden structure has been designed to double-up as a rather lovely headphone stand. This is a genius idea, especially if you're planning to site the Euterpe on a desk where real estate is already at a premium. Supplying the thing with juice is a substantial (95x63x185mm) linear power supply.

THE LISTENING

As well as sitting in my main system, the Euterpe partnered me during the day's toil connected to my PC. Speaking of which, don't be alarmed if you get an error message stating that Windows doesn't recognise the Auris head amp, as you've probably got the Source switch set to A instead of D. Not that this happened to me at all…

Feeding the Euterpe via USB, the DAC did a commendable job with Kate Bush's And Dream of Sheep. Via my reference closed-back Ultrasone Edition 15 Veritas headphones, I heard a realistic rendering of piano, acoustic guitar and whistle. At the same time, Kate's gentle vocal was presented slightly forward, softened by some subtle reverb. There was some rounding of the edges, but it was an enjoyable experience overall. That said, the Auris still dealt an excellent hand regarding timbre and expression, especially where piano and vocals were concerned.

Switching to the synth stylings of Eutropic, and the electronic beats were cold and exacting – albeit a little lacking in the snap that I enjoy from my solid-state setup. Male vocals and bass notes in tracks such as Awake had plenty of presence, and the kick drum pattern had my foot tapping. Although this valve amp might not be as analytical as I usually like, there was no hint that I was missing anything, be it incidental panned ambient effects or high frequency synthesised syncopations. Instead, its presentation reminded me of the feeling of first pressing the soft eject button of a high-end cassette deck years ago – it was refined, poised and butter-smooth.

I also sent some choice cuts from my virtual music library to the Euterpe through Chord's Qutest DAC, with the amplifier toggled into its analogue mode for sheer devilment. You know when you put your first aftermarket air filters into your car or hotter pickups in your guitar, and suddenly the thing you've known for a while becomes keener and feels more alive? That's what I had here. Most noticeable at first was an apparent increase in volume, but I also heard increased dynamic range with an improvement in instrumental separation.

Dropping the stylus down on the Human League's Mirror Man, I was prepared for the speed and lustre that I have come to associate with early eighties synth-pop. But instead, I heard a wider soundstage through my Oppo PM-1 open-backed planar cans, along with a sweeter and more flowing presentation. Phil Oakey's vocals had an added richness and sounded larger than many of the solid-state headphone amps I've had through the door. Granted, my reference Moon 430HA/D manages to supply both richness and stacks of detail, but it's also twice the price of the Euterpe and takes up much more desk space.

What the Auris does that the Moon cannot, however, is provide tube-tastic smoothness. Maybe this explains why Miles Davis's Kind of Blue seemed so very right with the Serbian headphone amp. I feared I would hear some tube noise, but all I got was wonderfully nuanced jazz. With the glowing tubes replacing the burning cigarette ends in a basement bar, the Euterpe tracked the players through dynamic changes with a surefootedness that I typically champion solid-state electronics for. Cannonball Adderley's Alto Sax in Freddie Freeloader had a deliciously visceral quality, this lovely looking amplifier delivering welcome added warmth.

Generally, during my listening sessions, I bounce between cherished albums that I know pretty much inside out, picking out tracks for specific listening cues. However, the Auris enticed me to stay put and keep listening to all sorts of stuff that I normally wouldn't. Indeed I found myself going through album after album with no sign of fatigue, such was the creamy balance of the Euterpe's presentation. That's no bad thing for a headphone amplifier…

Soundstaging was impressive, as I discovered when I revisited Andre Previn's Concerto in F: I. Allegro with the London Symphony Orchestra. Once more, it was the realism of the piano that struck me. Not only was the Euterpe able to keep up with the great man's conducting flourishes and the firecracker dynamics of the orchestra, but the way this tube amp was able to present instrumental timbre seemed to be above its pay grade. The string section was wrapped in a lovely, shimmering midband warmth, yet this didn't seem to impact any of the performance's transient speed or dynamic efficacy.

I really enjoyed the combination of tonal warmth and dynamism that the Auris was able to supply, and it is these characteristics that will see it win many friends. Also, its expansive soundstaging pushes past the listener's headset in a skilfully pleasant way. It's true that solid-state fans such as myself may notice its slightly opaque, romantic midband, yet this seems to breathe more life into tonally dry recordings and plumps out the thinner ones. It also helps make the Euterpe genuinely enjoyable to listen to, even over extended listening sessions.

THE VERDICT

Auris Audio's Euterpe does many things very well, then. In addition to looking great, it doubles up as a handy headphone stand. Then there's its flexibility of inputs; it can partner both analogue and digital sources well. However, it isn't without some minor foibles – for instance, the volume control can have you inadvertently turning the amplifier off, even before you hit the click. Also, the front toggle switches might, on occasion, lose either left or right channels due to some lateral give. Yet when all is said and done, it's still a pleasure to use and comes highly recommended – especially when paired with a better DAC.

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