AKURATE DS, KLIMAX DS
Stereoplay, Germany
Feb 2008
Klimax DS vs. Akurate DS
Synopsis (full translation of review below):
'Akurate DS and Klimax DS have been conceived for one purpose alone: to convert music stored on a hard disc into the highest quality audio signal possible … Hardly any other source has been moved into Stereoplay's listening room with as much anticipation as Linn's network players. Klimax DS left no room for doubt: a few inches will have to be added to the summit of Mount Olympus for this reference product … [it] performed like a dependable rope … coherent in every respect, with more authentic colouration and the utmost information density - you perceive each individual strand, yet all strands pull in the same direction.
Klimax DS stands magnificently on the winner's podium, isolated from the competition.
Klimax DS marks what is currently the best achievable performance in audio for network players and leaves mechanical/optical systems in the dust. Its little brother Akurate DS is not far behind. The perspective for the future is: fast Internet connection and music streaming.
Test Conclusion: Klimax DS sets new standards. It plays CD content from hard disc like no CD player can, and it widens the gap even further when it comes to high-definition content. Reference. Akurate DS,the little brother of Klimax DS, does the family proud: audio performance of the highest order; playing CD quality recordings even better than the legendary Sondek CD12."
Read the full review in the original German.
Full English translation
Splendid isolation’ - is this motto of the English kingdom being adopted as a guiding principle for the development of a Scottish high-end product? Let's put it this way; on this rare occasion, the Scots and the English actually agree!
Just as the British were able to stay isolated throughout their history by being an island, in the same way the Akurate DS and Klimax DS network players keep all potential problematic issues at arm's length. Be it the fundamental principle of not retrieving digital signals from a CD drive, which is liable to both optical and mechanical problems, but instead from a hard disc via a network; be it the absence of any multimedia gimmicks for screen display; be it the decision not even to offer digital inputs for external products.
Akurate DS and Klimax DS have been conceived for one purpose alone: to convert music stored on a hard disc into the highest quality audio signal possible. That much they have in common. The differences show up first in the price tag: Klimax DS at 15,000 Euro marks the upper limit in Linn's portfolio, while Akurate DS at 5,200 Euro costs significantly less than Linn's Akurate CD player.
From appearance alone, it’s obvious where Linn cut costs: the precious Klimax enclosure - machined from solid and weighing in at ten kilograms - is replaced with an "airy" metal enclosure in the Akurate DS.
Unequal Twins?
When it came to the electronic innards, Stereoplay had to look very closely to discern the differences. Power supply: identical. Circuit board layout: identical twins - the blue board in the Klimax only serves as a motivation to Linn staff: he who handles ‘blue’ knows he is contributing to a reference product. In the Klimax DS, there is a thick isolation barrier between input and converter section, but that's it.
In the population of the board, there are hardly any differences either. Both boards work with a Wolfson WM 8741 D/A converter (up to 192 kHz / 24 bits). There is also a sample rate converter by Analog Devices and a Virtex-4 chip by Xilinx. "We use its full 32-bit range for all arithmetic operations and only reduce this to 24 bits directly before the D/A converter", explains hardware engineer Trevor Stacey. Both Akurate DS and
Klimax DS use the same DSP algorithms for signal processing in the Virtex chip; the D/A converters also run in identical configuration.
There is, however, one big difference: Klimax DS uses two high-end audio isolation transformers by Lundahl in its output stage. ‘Splendid isolation’ here, too, then. The Lundahl components serve to achieve galvanic isolation. But not only that: "They form a perfectly linear low-pass filter", enthuses Stacey. "In the Akurate DS, we implemented that with high-quality polypropylene capacitors. This is complemented by an output conversion stage using op-amps - here we brought to bear our expertise from the CD12." Does this impact the audio performance? While the Klimax DS limits itself to two lossless audio formats (WAV and FLAC; MP3 only via ‘on-the-fly’ conversion by Twonky), the Akurate DS can play the lossy MP3 format directly, and can display artist and title metadata. Klimax DS does not even make this minor concession to usability but ultimately this is irrelevant: without certain peripherals, neither an Akurate DS nor a Klimax DS can operate to their full potential.
Need for Computer Skills?
It is not enough to have neatly "ripped" your music data to a hard disc. This hard disc must reside in a UPnP-capable NAS*. There, the ‘Twonky Media Server’ software takes charge of managing the music files and streams the raw data via routers and network cables to Linn's players.
While there is a small handset included, it only works after a playlist has been loaded into Linn's players either via a computer or a wirelessly connected Internet tablet, such as a Samsung Q1 or a Nokia N800.
Is this an insurmountable list of tasks and obstacles for end users? No, Linn has always relied on its specialist dealers to install turn-key solutions in the customer's home. When the system is up and running, it gives a grand screen performance - pardon, stage performance. Home cinema is not an option after all, as you might recall: splendid isolation...
*NAS-Server Required
Anybody who wants to enjoy music with either of Linn's DS products needs to engage in some hard disc related activities. Not only does the private CD collection need to be transferred to hard disc, but it also needs to be accessible over the network. Linn relies on NAS systems with Twonky Media Server. They offer about 1.5 terabytes of storage space, depending on the exact hard discs used, which equates to about 3,500 CDs in lossless FLAC format. A maximum of four hard discs are combined in a special arrangement (RAID) to guard against data loss -- when any one disc fails, no data is lost. You should not skimp on the price, since the server is running continuously: good hard discs and a high-quality NAS enclosure are de rigeur. NAS systems are not necessarily quiet -- but due to their network connection they do not have to sit alongside the hi-fi equipment. However, the server should not be relegated to a damp cellar either...
Pricked Ears in the Listening Room
Hardly any other source has been moved into Stereoplay's listening room with as much anticipation as Linn's network players. How does the Scots’ concept perform in action - dispensing with all mechanical parts and playing CDs from hard disc? How does a high-definition SACD sound in comparison to the high-definition download of a "studio master quality" recording from in-house label Linn Records? The first candidate to challenge the two network players obviously comes from the same stable: the Akurate CD player.
44.1/16
The display on the Akurate DS clearly shows this is a ripped CD. Jack Johnson, ‘In Between Dreams’ - frequently referenced by Stereoplay for its pronounced rhythmical and dynamic qualities. While the foot-tapping factor and audio quality were already at the very highest level with the CD player, the Akurate DS still trumped it: not only did Jack Johnson's voice stand out even more freely in the room, it also sounded less encumbered in itself and more relaxed. Instrumental phrasing was audibly more subtle and enjoyable - by contrast, the Akurate CD even appeared a bit sluggish. The bass: in the Akurate DS it was more precise, with more attack, but at the same time more slender than from CD.
Initially this looked like a plus point for Linn’s CD player - it appeared to produce a more coherent sound at the first listening. However, the longer the duel went on in the Stereoplay listening room between network and disc, the clearer it became: the network is simply superior in every respect. Melody arcs, the very finest rhythmical shifts, and most minute variations in phrasing were more audible from the hard disc. That is to say: the musical intentions of an artist, his interpretation, become more apparent via the Akurate DS.
Top of the World Klimax DS
With the testers frequently cross-checking while evaluating the Akurate DS, the Klimax DS left no room for doubt: a few inches will have to be added to the summit of Mount Olympus for this reference product. While the music was precise yet still a bit frayed with both Akurate products, the Klimax DS performed like a dependable rope: nothing could make it lose its full and detailed reproduction, coherent in every respect, with more authentic colouration and the utmost information density - you perceive each individual strand, yet all strands pull in the same direction.
Using high-definition content like Claire Martin's "He Never Mentioned Love" (96 kHz / 24 bits), the so-called grand piano turned even grander, the mighty action became even mightier, Claire Martin's voice came across even more nuanced, lightly hit cymbals were suddenly free from any irritating metallic flurry, how ever minimal it might be - here played only subtly textured and rhythm spouting metal. This result for the Klimax DS is surely due in part to the differently implemented filters, the Lundahl audio isolation transformers, and the solid metal enclosure.
Would the Klimax DS ... Could it possibly ... Should we...?
One look between the testers, tacit agreement, and reaching for the remote control: What happens when we pitch Naim's 23,300 Euro flagship CD555 (6/06) against the Klimax DS? Have a look at the STEREOPLAY point scores, and the question is answered: Klimax DS receives 66 points for CD recordings with 44.1 kHz / 16 bits after a comprehensively persuasive performance. Naim's player: 65 points.
Fed with high-definition content, Klimax DS trumps the SACD playback on the Akurate CD significantly with 68 points. (The latter's 70 steroplay audio points applied to multi-channel audio.) It also exceeds the player/converter combo CDSD/DCC2 by EMM-Labs (9/06; 66 SACD points). Klimax DS thus stands magnificently on the winner's podium, isolated from the competition.
What was that again about "splendid isolation"?
Reviewer: Jörg Witzsch
STEREOPLAY Test Result
Klimax DS marks what is currently the best achievable performance in audio for network players and leaves mechanical/optical systems in the dust. Its little brother Akurate DS is not far behind. The perspective for the future is: fast Internet connection and music streaming - flat rate subscription for high-definition content - even the NAS server at home then becomes expendable.
Klimax DS sets new standards. It plays CD content from hard disc like no CD player can, and it widens the gap even further when it comes to high-definition content. Reference.
Akurate DS, the little brother of Klimax DS, does the family proud: audio performance of the highest order; playing CD quality recordings even better than the legendary Sondek CD12, or the Akurate CD.
STEREOPLAY INTERVIEW with Gilad Tiefenbrun, Linn Director of Engineering
STEREOPLAY: What is the difference between Klimax DS and Akurate DS?
GT: There are no technological or financial constraints on Klimax DS. Our engineers were tasked with developing one thing only: the best-sounding product possible. Akurate DS is an adapted variant, which has benefited from the development of Klimax DS.
STEREOPLAY: Will we see a Linn preamplifier with network connection soon?
GT: Why not? But think even further: all your loudspeakers could have network electronics built into them, and they could receive music as well as configuration via the network - crossover characteristics, room correction and so on... that's what we understand an open system to be!
STEREOPLAY: How open is Linn with its system?
GT: In the short term, closed systems are simpler but more limited. An open system requires cooperation on standards, but it also offers better prospects for the future and more flexibility.
STEREOPLAY: When will we see HDMI-1.3 inputs for high-definition audio in Linn's products?
GT: Soon (laughs). For now, we have concentrated on getting our networked products to market. But HDMI in the preamp is coming.
STEREOPLAY: What has been the reaction to the DS products?
GT: The DS product line has opened a dialogue with customers, the likes of which we have only seen before with the LP12. The many possibilities offered by network players stimulate creativity enormously. Every day I receive emails with suggestions - an opportunity for us to engage much more closely with the realities of life of our customers. But you know, even though we are talking a lot about technology here, for us, the overriding concern is the music. At the end of the day, it is the enjoyment from the experience that counts: you sit down comfortably in an armchair and enjoy the music.
