Nagra HD DAC
FOR Natural, informative sound; rhythmic ability; dynamics; build AGAINST The display could be better
What’s the best DAC in the world? The best we’ve heard so far are Chord’s DAVE and dcs’s Rossini Dac/clock combination. To that rather short and hugely talented list you can confidently add Nagra’s HD DAC – and it’s arguably the most desirable of the lot.
Nagra’s level of digital competence comes as something of a surprise to us. The HD DAC isn’t the company’s first digital product – it’s made recorders, DACS and other digital products for decades – but it’s the Swiss brand’s preamplifiers and power amplification that grab the limelight in high-end circles.
We love the appearance of Nagra products, but it’s a shame the company hasn’t differentiated the HD DAC a little more from legacy products. This unit is part of the no-compromise HD range, and represents a ground-up rethink on how a digital-to-analogue converter should be designed. It’s easy to lose sight of that fact when the unit looks the same as products that were designed decades ago. But make no mistake; this really is an all-new, cutting-edge design where rare, older electronic circuit techniques rub shoulders with innovative new ideas.
Like every Nagra product we’ve seen, the HD DAC is immaculately made. Each panel is superbly machined and the unit as a whole feels immensely solid and robust. The price is high, but this is an investment that is designed to work for decades to come.
It’s a compact unit, measuring just under 8cm high and 31cm wide. The front is dominated by the brand’s trademark signal-level meter and stylised volume control. The latter confirms that this product can be connected directly into a power amp or active speakers.
All in one
Such a system configuration keeps the signal path short by bypassing the need for a dedicated preamp and the lengths of connecting interconnects used in between. The result should be a clearer, more transparent sound. On paper the only downside is the lack of compatibility with analogue sources.
There’s a small display on the HD DAC’S front panel that suits the product’s understated nature, but it isn’t easy to read from a distance, or if you go off-axis.
Elsewhere, there are lovely little metal switches for mute and to toggle the DAC’S output between line-level – singleended RCA and balanced XLR options – and the 6.3mm headphone socket.
Look around the back and you’ll find the full array of digital inputs from USB, coaxial (in both RCA and BNC forms) and optical, to a pair of AES/EBUS and a dedicated Nagra I2 S option. You won’t find an IEC mains input though. Instead there are dedicated, separate power feeds for the analogue and digital sections, suggesting a sophisticated power supply arrangement.
We’ve come to the point where cutting-edge premium DACS will play pretty much any established file type, and the Nagra continues that trend. Its digital file compatibility is comprehensive, covering PCM up to 24-bit/384khz and double-speed DSD. Bar some ultra-niche recordings, that should cover pretty much all the music files out there.
Take a look inside the Nagra and you’ll find plenty of clever and innovative engineering. Great care is taken to maintain the integrity and transfer of the digital data stream. The signal, even if it’s PCM, is converted to double-speed DSD internally. It’s then processed by a powerful, high-spec FPGA (Field Programmable Gate Array) that runs proprietary software majoring on timing precision, low distortion and generating a minimum of noise.
The analogue stage is similarly unusual and clever. It uses Nagra’s expertise in transformers (handmade in-house) and valves (a single JAN 5963 double triode) to maintain signal integrity. The 5963 valve was engineered
to work in digital circuits and was used in the first computers.
This was at a time before the first transistors became available, so its use in a high-end number-crunching modern DAC is kind of poetic. At this level it should come as no surprise that the HD DAC is kitted out with high-grade internal components and made with almost obsessive levels of care. That’s the least we would expect for this price.
The Nagra’s power-supply arrangement features 25 separate internal supplies fed by two outboard units – one dedicated to the analogue section and the other for the digital. At this level, it makes sense to spend the extra £5100 it takes to own the MPS outboard power supply with its option of using ultra-low-noise battery power. Once you’ve heard the sonic improvement the MPS makes across the board, it’s hard to do without.
Equipment at this level needs a top-class digital source if you’re to get the best from it. We use our reference Naim NDS/555PS music streamer for most of this test, but also draft in a Macbook Pro (loaded with Pure Music media software and plenty of goodquality hi-res files). We also use the Gamut D200i power amplifier as well as Nagra’s Classic Amp (also a power amp), feeding ATC SCM50 and Spendor Classic 2/3 speakers. All cables are from the premium end of Chord Cable’s range.
But there’s more to optimising the HD DAC than just finding quality partners. Like most equipment, it is sensitive to the support it’s placed on – the high level of transparency of any suitable partnering system makes even the smallest differences obvious – so use a low-resonance rack or shelf for the best results. Something that offers a good degree of isolation is a good idea.
It takes no more than a few seconds to realise that the performance of the HD DAC is straight out of the top drawer. We start using it with our usual Gamut D3i preamp, later swapping to Nagra’s excellent Classic Preamp, but it doesn’t take long to decide to plug the HD DAC directly into the power amp. The system sounds clearer and more natural in such a configuration.
We play Bizet’s Carmen Suite and are treated to a wonderfully organic sound. If you think digital equipment can’t sound
“It’s a wonderfully organic sound. If you think digital kit can’t sound natural, this DAC will prove you wrong”
natural, this DAC will prove you wrong. The presentation has scale and authority, with a soundstage that’s as expansive as it is stable. Instruments are locked into position and the DAC maintains a pleasing sense of space around the instrumentation, no matter how dense or complex the music gets. It’s easy to follow instrumental strands, even if they’re low-level and in the background.
Things are convincing tonally. The Nagra is evenly balanced and admirably neutral, so instruments (and any voices present in the recording) sound believable with authentic textures and a pleasing degree of body. While there’s plenty of refinement and a total lack of unwanted hardness, there remains a healthy dose of dynamic punch when required. The violent dynamic swings in the Carmen Suite are rendered with confidence and enthusiasm – the switch from quiet to loud and back again being handled with rare fluidity.
As we listen longer, we realise that the Nagra is digging out an uncommon amount of detail, even considering its lofty price. This detail isn’t thrown at the listener in a bid to impress, but is strictly organised and proportioned to serve the recording. The Nagra doesn’t demand the spotlight – it steps out of the way, leaving the music to grab our attention.
Playing a range of music can’t wrongfoot this DAC, either. Play some Nine Inch Nails and there’s plenty of attack and aggression, leaving the excitement intact. Switch to Bon Iver’s
22, Million set and the Nagra’s excellent organisation coupled with superb rhythmic cohesion makes light work of the album’s complex production. Yet, when it comes to voices – in Aretha Franklin’s Dr Feelgood or Adele’s
Hometown Glory, for instance – the HD DAC sounds pure and transparent. It really is a brilliant all-rounder.
The story is just as positive through the headphone output. This has no problem driving the likes of Beyerdynamic’s T1s and Grado’s RS1 to high levels, and retains the same admirable sonic characteristics as the line stages.
The DCS Rossini Dac/clock combination remains a terrific proposition and has the
added attraction of a built-in UPNP streamer that can access music through your home network. It just about edges the Nagra in outright detail resolution, but the HD DAC sounds more enticing and natural. Chord’s DAVE is terrific value in comparison to either the DCS or Nagra, but isn’t as rounded a performer.
If you’re in the market for the ultimate DAC, you can hardly go wrong with any of those three – they are all excellent in their own ways. But, if we had to choose, our money would go to Nagra.
“Excellent organisation coupled with superb cohesion makes light work of the album’s complex production”
Tried and tested circuit techniques rub shoulders with innovative ideas
Old-school design with immaculate build quality: a winning combination
Note the separate power feeds for the analogue and digital sections