Actually, you've got the right idea, but the wrong details.
The HDMI format licensing doesn't allow any player device to take the digital audio content it plays from the SACD and send it out at full digital audio quality (without down-sampling) over any connection that isn't considered "secure". As far as I know this would include both DSD and PCM at a high-enough bit rate to be considered "full quality". You are allowed to send the content out via HDMI because the HDMI connection itself is encrypted and secure; no other type of digital connection commonly in use complies with this. (The whole reason for the restriction is copy protection. Only companies who have licensed HDMI can use it, and part of that license agreement includes the promise that they will honor the copy protection flags - for example, no HDMI licensee will sell you an HDMI-input digital audio recorder that will be willing to record audio that is flagged as "copy protected", which includes all content that originates on SACDs. Since S/PDIF is very prevalent, and doesn't require a license agreement, there's no way they could ensure this, so the simple solution was to block
ALL output over "unsecure" outputs.) Note that this is specifically tied in with SACDs, and not with the DSD format, so any device can theoretically play a DSD
FILE without restrictions.
However, the DSD format itself isn't terribly prevalent outside of SACDs. The XMC-1 can play DSD content it receives via HDMI, as can a few other pre/pros and AVRs, and even a few current DACs. You can also send DSD encapsulated over a USB connection using a format called DOP (DSD-over-PCM), but it isn't at all widely supported, and the XMC-1 doesn't support it. (Hardware SACD players don't have USB outputs; computers usually do have USB audio output capabilities, but SACDs can only be played on SACD player
HARDWARE, and there are no SACD drives that you can connect to a computer, so the
ONLY available computer DSD sources are downloads... and files that have been ripped from SACDs using some other hardware - which presumably don't "know" they came from an SACD, and so may or may not be treated the same as DSD downloads. Note that only certain player programs support DOP anyway. Also note that some players may give you a down-sampled version of the audio on the SACD over a non-HDMI digital output, as will some "splitter boxes", but most simply mute the output entirely when you try any output except HDMI. There also may be some few foreign made devices that
WILL give you a full quality digital audio output, via some format other than HDMI, from an SACD source - but they are illegal.
(Also note that, as well as actual SACD discs, some older Oppo models used to be able to play ISO images of SACD discs directly, but this functionality has been
REMOVED from current models, and from recent firmware on the 93 and 95. At the moment Foobar2000 can still play SACD ISO files with the appropriate plugin, and some other software players - like jRiver -
MAY be able to... you'd have to check that. There are also other "quirks"; for example, some players may disable
ALL output if you try to play an SACD via some non-HDMI output; so, for example, if you enable the S/PDIF output on a player while playing an SACD, it may suppress digital audio output on
ALL of its outputs - including HDMI - because the mute/protection function has been triggered. )
Unlike DVD-A, it also seems to be part of the standard that
ALL SACD audio discs are copy protected, so you won't find some discs that this doesn't apply to. I have also never seen a DSD download file that
WAS copy protected. (I don't know if that flag is available for files not originating on SACD media, but nobody uses it, or if it actually can't be done. I'm sure you can find more specific details about this on the web...)
I think I remember reading SACD licensing forbade to send DSD direct from a device that is not currently playing the disc.
Reason why it would work from an SACD player but not a player reading DSD files. There may be a way to use the Oppo with an add-on card that turns it into a streamer and hack the disc verification...
Some companies are not reading that license to the letter and allow their devices to send/receive DSD stream whatever the source is, but I think the choice was made by Emotiva to be strict about it.
