Back in 2007, Linn Products launched a game-changing product called the Klimax DS. It was the first post-physical digital streaming player to really take music seriously. It underwent a couple of changes in the intervening years, but the basic package remained essentially unchanged for one very obvious reason – it sounded bloody good. 2007 in streamer years is ancient, but the Klimax DS has stayed the course, and any Klimax player can be brought up to date to the latest ‘DS/2’ standard.
But now there’s the Linn Klimax DS (the so-called ‘DS/3’), and everything has changed. And, of course, what changed with the DS also applies to the DSM, which adds HDMI and line-level preamp functionality to the standard DS streamer. As both of these products feature the Exakt RJ45 links for fully digital active (aktiv, in Linn-speak) connections to many Linn, B&W, KEF, and Kudos speakers, the preamp is superfluous unless you are adding a line-level source.
The core (kore?) of the latest upgrade is what Linn calls its Katalyst DAC architecture. In many digital systems, digital conversion takes place under fairly tightly constrained digital architectural limitations: the circuit itself is often a variation on a theme of the application notes or application board sent out by the chip designer. In fairness to some makers, there are not a lot of options open to an audio engineer faced with a chip that has very tightly specified demands, but this leads to the somewhat erroneous but understandable concept that any digital product essentially ‘sounds like its chips’.
Those who know their way around digital design don’t follow so narrow a path. Some – like Chord Electronics and dCS – go as far as to design their own DAC from scratch. Linn went instead with the Katalyst architecture, and just as the Exakt system launched to the pithy ‘the source is in the speaker’ sound-byte, so Katalyst and Klimax is all about ‘a DAC is more than just a chip’. Katalyst involved scanning all the chip catalogues on the planet in search of devices flexible enough to accept not just a single voltage, but multiple power supply feeds – two for modulation and three for the conversion stage – all fed from an extremely stable and fully isolated voltage source. This is perhaps not unexpected from a company like Linn, which has a long history in making stable voltage power supplies for devices like the Radikal for the LP12 turntable, but the process required looking beyond the usual suspects for DAC chips, all of which accept a limited voltage input to the chip, despite that power feeding a range of different sub-systems within the DAC.
Power feed alone makes a big difference to the performance of the DAC, but that’s only part of the Katalyst architecture. The signal is fed through a data optimization process (a 16x, 768kHz upsampler working at 35 bit precision, then to a 8x, 6.144MHz modulator) before being passed to an array of bitstream DACs, and finally passed to a new analogue output driver. The whole digital signal path from upsampler to the main conversion of the DAC array, is governed by a high precision master clock.
This data optimization system largely obviates the need for super high-resolution files and DSD, because the upsampling process raises 16/44 to 24/192 PCM files up to such a high performance level internally. Given Linn has been able to track what digital streaming users actually listen to (not individual listeners in some kind of Big Brother tracking, but the Linn DS users as a cohort), it seems that we are moving away from local collections of manicured super high-resolution files and toward online services like TIDAL. As a result, the company sees no need to break its own rules about ‘open, commonly used’ formats. Moreover, Linn’s Studio Master recordings are sold as 24/192 FLAC files, but are also sold as SACD discs, so I guess they would have a good track onwhat is and isn’t important in high resolution audio. This is at odds with the somewhat enforced DSD/MQA ‘acronym arms race’, and I respect Linn’s stance on this.