Thursday 18 April 2013

DSD – The Next Big Thing?

The bleeding edge of the audiophile universe – inhabited by those of us who probe ever deeper into the outer reaches of diminishing returns in search of audio playback perfection – is strangely characterized by apparently outdated, abandoned, superseded technologies, shouting their last hurrahs in stunningly expensive Technicolor. Tubes and turntables are guilty as charged here, and I own both.

Why do some apparently stone-age technologies still persist, yet others less venerable vanish never to be heard from again (hello cassette tapes, receivers, and soon CD players)? In the cases of tubes and turntables, I venture to suggest that these are technologies which, at their zenith, were the products of craftsmanship and ‘black art’ rather than the concentrated application of science. Their full scientific potential was never truly reached, and they were replaced for reasons of practicality, convenience, and cost. But they still have not gone away.

A slightly different situation arose for the SACD, a technology developed by Sony and Philips as an intended replacement for the CD around the turn of the millenium. SACD was designed from the start to be a vehicle for delivering notable superior sound quality compared to the CD, which is strange, since the same two companies foisted CD on us under the pretext of “Pure Perfect Sound, Forever”. But whereas in the 1980’s they were able to create a real consumer demand for a delivery platform which was convincingly marketed as being superior to the LP, with SACD they found that there was in fact no market interest in a sound quality superior to CD. In fact, their customers were more preoccupied with a delivery format of demonstrably INFERIOR sound quality – the MP3 file. But that is another story.

The SACD fizzled upon launch, but thanks to the Japanese, it didn’t actually die. There is a healthy market for the SACD in Japan, and this is sufficient to keep the format alive, if not necessarily healthy. So what is it with the SACD? Does it actually sound better? And if so, how does it do that?

Well, yes, there is broadly held agreement that SACD does indeed sound markedly better than CD, and arguably even CD’s high-resolution PCM format cousins (with 24-bit bit depth and higher sampling rates). You see, SACD stores its digital music in a totally different way than CD. It uses a format called DSD, which I shall not go into here, save to say that conversion from DSD to PCM seems to consistently result in some significant sacrifice of sound quality.

Here in the West, where we never really adopted the SACD, we moved from listening to music on CDs to listening to music stored in computer files. So, instead of wondering whether or not to adopt the SACD, we ask whether or not we can store music in DSD format in computer files and have the best of both worlds. Well, of course we can! What did you think?...

Two file formats, one developed by Sony called DSF, and one developed by Philips called DFF, seem to have recently emerged. If you have a PC, you can easily send DSD bitstreams from DSF and DFF files to DACs that support DSD. In the Mac, it is a little more complicated, and there is an emerging standard called DoP (DSD over PCM) which enables Mac users to transmit DSD over USB and other asynchronous communications interfaces. Boutique record labels are emerging, such as Blue Coast Records, which record exclusively in DSD, and sell DSF/DFF files for download.

Perhaps most intriguing is that many of the major labels – but DON’T go looking for much in the way of public acknowledgement – have discovered a preference for using the DSD format for archival of their analog tape back catalog, having once already gone down the path of digitizing it to PCM and finding it to have been sadly lacking. Don’t look for this to happen any time soon, but this lays the groundwork for the major labels to finally release their back catalog in a format that truly captures the sound quality of the original master tapes. Before that happens, the labels are going to have to realize that the only sustainable format for music distribution is going to be one that works on-line, and they are going to have to find a way to make that work for them.

DSD could end up emerging as the format of choice for audiophile quality audio playback.