As we end our series on PCM and DSD I have been fielding a lot of questions concerning our products and the lack of a DSD input. A few of you have also asked why we don't have an SACD player and so on.
Let me share with you a few of the issues going on and shed some light onto this subject. The first thing we should do is make a distinction between SACD and DSD. While they use the same format, SACD is a proprietary optical disc of Sony (not a format)and all SACD releases from Sony are copy protected as well as heavily guarded against getting a digital output of the original data under any circumstance.
Sony was a pioneer in the recording of and remastering of original high resolution audio material from artists. First introduced in 1999, which coincidentally was around the same time as Napster was giving the music industry fits and Steve Jobs was negotiating deals for legal download of music, Sony had to convince wary artists that they could offer 100% protection for the music. Remember, the music industry was upset about CD copying and MP3 sharing and along comes Sony asking for the right to distribute openly what was essentially the master tapes! CD copying is bad enough, in the eyes of the music industry, but to give any kind of access to the far superior master tapes was just nuts. It was a big challenge and frankly I tip my hat to the army of lawyers that pulled it off.
Each copy of a SACD has a unique ID and it has proven nearly impossible for anyone to crack the encryption scheme used to prevent copying. Legally you cannot make the raw unencrypted content of a SACD available in digitally. You may have seen SACD and Blu Ray players that have HDMI digital outputs that can go into a receiver or DAC, but I can assure you that the decoding of the encrypted data stream on the HDMI cable happens only inside the chip itself in the DAC. What's in the HDMI data is encrypted and of no use to a DSD capable DAC.
Products like the Oppo output an unencrypted DSD stream but it is by no means the raw DSD stream - instead it is a truncated and reduced version that is not even close to the original. Many SACD players also output a digital audio stream that many believe is the raw data, but this is actually PCM from a second layer on the SACD that Sony included so if you bought the disc but didn't have a SACD player you could still play the disc in your CD player.
Sony simply cannot ever allow the raw DSD data to be available because if it did then one could easily copy that data and that would violate all the agreements they have in place with the artists. You really cannot blame Sony for this, I am sure any lawyer would have a field day if they did.
With respect to a DSD capable DAC from PS Audio, let's look at that tomorrow and then we'll move on.