Cambridge Audio Azur 851D DAC

Someplace around the turn of the millennium, hi fi began becoming interesting again - with DVD Audio and SACD arriving, MP3 going computer audio and gangbusters taking hold. Afterward asynchronous USB conferred hires ability on PCs and Macs, and simple wireless has come to aptX Bluetooth. Cambridge Audio's new main DAC is an item of this. Packed with most of the functionality that's popped up within the past decade, it purports to be a 'greatest hits of digital' in one convenient package.

Product manager Sam Ellenby says it's for, "a pretty sizeable market of those who desire to know they are essentially hearing an uncoloured, unhindered reproduction of their source material." Fair enough, but the flagship Azur 851D is an expensive box of tricks, and Cambridge Audio has been linked with apparel that is more affordable. Which begs the question, could it be good enough to get folks who had normally buy more upmarket brand names interested? The organization thinks so, calling it "the last word in high-end digital-analogue conversion."

Well it's certainly enormous and heavy to get a DAC, and is very nicely finished at the price. What controls the fascia is backlit and a large volume control, reverse-video LC screen. The latter has eight inputs - including various traditional digital ins, plus asynchronous USB and aptX Bluetooth via a bundled dongle. The volume control can be bypassed, as well as the component configured to act as a DAC, or it can be enabled and used to drive a stereo power amplifier like Cambridge Audio's 851W.

The unit offers twin Analog Devices AD1955 24-bit DAC chips, working in double differential mode, and comes fitted with ATF2 sound upsampling 24-bit/384kHz. It works on the special adaptive time filtering algorithm that de-jitters all digital sources and can also upsample them to 24-bit/384kHz. Upsampling itself isn't new, but the 851D's execution is unique to Cambridge Audio. It is asserted that it makes for a substantially smoother, more period-coherent sound, as all of the digital number crunching is taken far from the audio band that the resulting analogue signal can't be interfered with by it. Although not a view that is completely unanimous, many feel it's a worthwhile feature. User selectable digital filters - steep, linear phase, minimal stage - are supplied.

Sound quality

This is really an extremely clear and explicit sounding digital converter. Compared into a current HFC favourite, Audiolab's MDAC, it supplies the sense of being the font of all detail. There is masses of it, flooding out like flavour from a teabag! The 851D brims with info concerning the recording, in the exact location of all instruments over the stereo soundstage, to their front-to-back that is relative spatiality. It locks instruments in the mixture quite boldly to precise points within the recorded acoustic guitar, and never lets go. It seems very good on leading edges also, giving a very 'etched' sound which you can not fail to blow off.

That is a soft and fairly smooth sounding track by the ultra computerised standards of contemporary recordings, but the Cambridge Audio actually brings the music from its shell. Although you'd never call it harsh it gives an especially upfront sound to the proceeding. Vocalist Donald Fagen appears closer and much more intimate than is frequently the situation, on this track he usually sounds - to borrow one of his own phrases, "languid and bittersweet". Percussion is punchy and extremely tight; hi hats thump on cymbals and tough shimmer with energy that is metallic. This is an actual seat of the trousers sound.

Whereas the latter seems fairly sumptuous and silky, the Azur 851D is a good deal more upfront and in your face - believe The Ramones to the Chord's Barry White. This is not a criticism necessarily, but you will not want to drop it into an already -sounding system. Feed the 851D a brightish recording like Ride's Twisterella and you'll believe every strum of the lads' guitar strings resound round the heavily EQ'd, together with the area and compressed vocal tracks pushing out at you with a vengeance. This, no shrinking violet! The switchable filters can help here, with all the Linear setting coming over as the most sounding in my review system, and Steep being the smoothest. The others have a subtle effect, to varying amounts making the music marginally more effusive, but in the cost of a subtle amount of space and atmosphere.

In all fairness, a well chosen interconnect cable would help better here - and you'd be thinking than Nordost. Give a good to this DAC, well balanced record, though, and it's in its element. Yellow Magic Orchestra's Technopolis is a track I Have listened to thousands of times, and I'm surprised to be honing in on modest nuances I Had not heard before - little details like the subtly textured sound of the lead synthesiser, as an example. Make no mistake, that is a really high resolution device.

What better then than feeding it with some hi-res music? REM's Texarkana is left with dizzying quantities of detail - you must get into dCS Debussy land at almost 10 times the cost about what the Cambridge Audio gets out of the computer equivalent of the record groove to actually improve. That little awareness of being 'brilliantly lit' subsides slightly with higher resolution digital files, the DAC seeming to fill out tonally and get a bit more body. Bass Guitar isn't good at 16-bit, but with hi-res it does get a touch more ample and better curved as it should.

Bluetooth works nicely; the 851D gives a punchy performance of Grace Jones' Slave To The Rhythm from an iPad. But just as the hi-res takes this DAC to warmer, fuller climes, so it is taken by the Bluetooth in the opposite direction. The lesser resolution file quality makes for a slightly plasticky feel to lighter low frequencies and the music - although it definitely retains its rhythmic snap. Although not as 'hifi' as its proponents would have you believe, I'm a big fan of this connection approach and regard it as genuinely useful functionality that is extra. There are several times when you just want to play with a track or two while you are doing something else, and Bluetooth is fantastic for this.

This really is an extremely great DAC giving a powerful, elegantly etched sound with exceptional spatiality. But not everyone will like it, because it is a bit more of a 'Marmite' merchandise than some. Its explicit and upfront sound may put some people off that look for a more mellifluous demo. For instance, the Chord Qute DAC appears better in a position to enter into the rhythmic subtleties of a song, it swings as well as a more instinctive feel for the groove on Sister Sledge's We Are Family, as an example. By contrast, the Cambridge Audio goes out of its way to tell you all in regards to the recording, in the event the 2nd backing singer was getting over a cold or whether the bass guitar had a slight buzz on a fret. It is a technical, cerebral demonstration; it's no less capable, but some will think it less pleasing.


An exceptional digital converter, it is one of the most detailed, insightful performers this side of the multi-thousand pound super-DACs, and many prospective purchasers will likely be dazzled by its own sound that is great, wide selection of connections and sturdy build. Furthermore, if you've already got a power amplifier, it creates great sense to put it to use as a preamplifier, giving better sound along the way and saving you money. However, it's well worth before you buy auditioning it in the body, because it will not be to all tastes - musical and otherwise. I discover it shines with electronic and established material, and operates best with sweeter, warmer sounding amplifiers and loudspeakers.

Cambridge Audio Azur 851D DAC photo