Headphones

As one approaches gear at lower price points, every pound matters that much more. It's simply a fact of life: the customer for Auris Audio's Nirvana high-end headphone amp [HFN Jun '19], at £4900, might be cavalier about issues such as value-for-money, features, finish or other details. Not so the prospective client for Auris Audio's £1499 Euterpe, because the market is over-burdened with serious competitors and money is more of a determinant.

Staring me in the face, as I review the Euterpe, is a permanent fixture on my desk: Quad's PA-One [HFN Feb '15], which sells for £100 less. It's daring me to compare it with the Euterpe, especially when it comes to facilities. Also, while the PA-One is equipped with 6SL7 and 6SN7 double triodes, our sample of the Euterpe was fitted with two PL95 tubes and one ECC81.

Users can specify EL95s so I rummaged through my spares boxes to see if Auris Audio chose the best for the application. I am happy to report that 1) the combination as supplied bettered what I could come up with, and 2) it also offered the most punch, oomph and sheer power, should you own hungry headphones or have a self-destructive penchant for ear-bursting levels.

Tube Choice
As this unit arrived without formal instructions, I had to rely on my wits to set it up. Which means that even were I witless, I would have had it up-and-running in minutes. The only item that needed explaining was the toggle on the top plate, to choose between PL95 and EL95 tubes.

As for the rest, it's utterly straightforward. The beautifully-made, 95x63x185mm (whd) extruded-metal power supply sports two orange LEDs on the front, showing power on with indications for both low and high voltage. At the back is the main on/off switch, an IEC three-pin socket for AC and a captive lead to connect to the Euterpe via a multi-pin connector located at the bottom of the back panel.

Other connections offered are RCA phono sockets for one line-level source and a line output, so you could also use this as a two-source preamp. There's also a built-in ESS Sabre-powered DAC, accessible only via USB-B connector, which I duly used to hook up my MacBook Pro. On the top of the unit, in addition to the selector toggle, are three valves protected by four black metal crossbars and the handsome wooden side cheeks. They determine the unit's height and are shaped to allow it to serve as a headphone stand – a nice touch. The main unit's dimensions with which to be concerned are those of the footprint, at 160mm wide and 230mm deep, adding stability to the 280mm-tall unit.

On the front is a rotary volume control that also acts as the on/off switch, illuminating or extinguishing the orange LEDs on the power supply. There's another orange LED on the front of the Euterpe, between a pair of toggle switches and above the headphone socket, which flashes briefly until the unit is fully on. Warm-up from cold takes mere minutes.

Toggle Talk
That lone headphone socket accepts only a ¼in jack so balanced output, for those who swear by it, is not addressed as it is on the Nirvana. On the left side of the socket is the toggle for choosing Source A (line input) or B (digital) and on the right a choice between high and low impedance (headphone) output.

Let's deal with the latter right off, so you don't get distracted. As there was, to my ears, merely a drop in level every time I flicked the switch, sometimes with a loss of openness, I used the selector according to sound quality model-by-model rather than according to the specs of the headphones, though I typically preferred the low position every time. My litany of cans included Audezes from both ends of the catalogue – the Sine (30ohm) and the LCD-4z (15ohm), Beyerdynamic DT48 (25ohm) and the venerable Sennheiser HD414 Anniversary (52ohm version). Sources included reel-to-reel tape, vinyl via TechDAS Air Force III Premium/TDC01 Ti [HFN Jun '19 and Sept '14] and digital feeds from Wolfgang's Vault, Tidal and others. Suffice it to say, the DAC section sounds very smooth...

Sumptuous Sounds
While on the subject of the DAC, and being in the mood for distaff vocals, I was delighted to locate Carly Simon's 2009 performance of 'You're So Vain' [via wolfgangs.com], an unplugged studio performance with her son Ben and loads of acoustic guitars. Even with the closed-back cans, the sound extended beyond my ears, being delightfully open and particularly enjoyable because of their harmonising. OK, the years were showing on Carly Simon's voice but it gave the performance a veracity of the warts 'n' all type.