Outboard DACs

Audio Research explains the role of the DAC7 thus: ‘With the growth of the iTunes culture and the increasing popularity of storing music on a hard drive, we were asked repeatedly to offer a USB DAC that could connect with Macs, PCs and servers to deliver a new benchmark in high resolution digital music playback’. It responded with a righteous solution that doesn’t pay mere lip service to iPods, servers and the like, because it’s an irresistibly musical device when used in a strictly traditional manner: fed by a CD transport.
   So good was the performance when used with the Marantz CD12 transport and Quad’s CDP99 Mk II CD player that I approached the need to audition other sources grudgingly. Yes, I have a hundreds of tracks on my notebook PC and mobile phone, but the test was my son’s computer – his primary source of music. I had to smile toward Minnesota when he plugged in his Dell Inspiron 1525 notebook (cost: under £400) and had it playing within 30 seconds. Audio Research may mean  purist audiophilia to most of us, but it has learned the ways of the young: the DAC7 is no old fart’s toy.
   But then I am an old fart, and couldn’t give a toss about connecting my primary sound system to anything with a USB output. My attitude toward servers is utterly dismissive: I’m not so infirm that I can’t manage to feed my player a disc at a time. In fact, I enjoy the act of selecting a title, opening the jewel box, slipping in the disc. I get enough ‘mouse-ercise’ working for a living. So forgive me if this review concentrates on the DAC7’s role in a high-end two-channel context. Suffice it to say, it sounds too good for the majority of material which will enter via its USB socket.

NOTHING NEGLECTED
While accommodating USB, Audio Research did not neglect the more familiar inputs. This unit is genuinely flexible, and you’d have to be a psycho-grade audiophile – eg, one of those Japanese whack-jobs who uses a different CD player for CDs from each record company – to require more inputs. The USB input covers 1.0 and 2.0 16-bit material, from 32kHz to 48kHz, and addresses both MAC or PC. The others all handle 16/32 to 24/192 and include: 75ohm RCA via phonos, 75ohm BNC, 110ohm AES/EBU through XLRs and Toslink for optical (I tried all but the BNC). Analogue outputs include single-ended RCAs and balanced XLRs, the latter feeding the McIntosh C2200 preamp, into the MC2102, driving Nola Vipers [see p32] and LS3/5As.
   Matching the look of ARC’s preamplifiers and measuring 480 x 134 x 254mm (whd), the DAC7 features four buttons on the front panel for Power, Mute, Invert and Input Select. The remote, though, operates those commands as well as the Play/Pause, Stop, Track Up and Track Down functions of a USB device, demonstrating with assuredness that the USB socket isn’t merely paying lip-service to the technology. The DAC7 uses green LED tell-tales to let you know the signal has been locked in, as well as indicating Power-on, Mute, Invert and which source is selected.
   If you want valves, look elsewhere. The DAC7 is a fully-balanced, solid-state processor employing a direct-coupled FET output stage and regulated power supplies, with seven stages of regulation. ARC fitted separate audio and digital power transformers, mounted on PCBs made of the same material as used in the Reference models. Inside, there’s a 24-bit/192-capable Burr-Brown DAC which uses ‘passive I/V conversion for best sonics’.

GOING BACK IN TIME…
Set-up was of the no-brainer variety, especially the aforementioned use with a computer. The best sound was all-balanced, the Marantz CD12 absolutely loving the ARC DAC, sounding sweet and warm and rounded, a big, fat Barolo of a sound – rich, sophisticated and full of nuance. Even with seemingly creaky material, the DAC7 seduced such sounds out of conventional CDs that I wish it had been available in time to curtail the format war of SACD vs DVD-A. Yeah: that good, if not capable of multichannel sound like those doomed formats.
   After the usual run of Keb’ Mo’, Eva Cassidy and other warm-up discs, I slipped in CDs from Louis Armstrong’s The Complete Hot Five and Hot Seven Recordings (which date from the 1920s). It wasn’t the well-preserved, familiar tracks that showed what the ARC could do, but the rare cuts which were probably culled from well-worn 78s. I swear I heard front-to-back layering of cornet and piano on the ‘rare’ take of ‘Drop That Sack’, while the staccato of Armstrong’s fast fingering belied 80-plus years of recording technology.
   Auditioning what may be a state-of-the-art DAC with recordings so old as to warrant the term ‘antediluvian’ isn’t a case of being ironic: the DAC7’s entire raison d’être is resolution, fidelity and getting closer to the music. As with the best LP spinners, which allow you to ignore the surface noise on second-hand treasures that never saw a carbon-fibre brush, the DAC7 somehow renders utterly unimportant the 78rpm crackles not stripped away in the remastering. While those fortunate enough to own the original 10in shellacs wouldn’t touch this with a 10ft tonearm, I for one was pleased to hear Armstrong’s ‘Muskrat Ramble’ sounding, oh, 30 years younger than it actually is.

…AND COMING UP TO DATE
   Turning the dial ahead eight decades, and last year’s live One Man Band from James Taylor, recorded sympathetically and with great sensitivity, also showed how far ‘Red Book’ CD has come in a quarter-century. A chiming character to the piano, a richness to the acoustic guitar, a warmth to a voice I’ve heard so many times it chokes me – including a live gig back in ’71 – complemented the real giveaway with live recordings: applause that didn’t sound like it needed a bowl, cold milk and sliced banana.
   Regardless of source – Marantz transport, Quad CD player, Dell notebook – the DAC7 possesses an air of Good Samaritan. It’s as if the designers built in a sense of William Zane Johnson’s high-end pater familias status, some sort of guiding force encouraging the music not to sound digital. And that’s a Good Thing.

VERDICT
It’s been ages since stand-alone DACs inspired interest, but the times forced a revival. ARC has addressed – rather than embraced – the age of servers et al with a DAC as sublime as any I’ve heard, as close as it gets to my hot-rodded Marantz DA12. What’s so surprising is the DAC7’s price. As for CD feeds, I can’t name another DAC which I would rather use.

Originally published in the December 2008 issue