Most CD and DVD players have analog and digital connections. The digital connections are coax and/or optical. Either can transmit the stereo CDs, DTS CDs, DTS DVDs, Dolby Digital DVDs, etc. Although there's an anlog connection, it's not used much, except for stereo CDs. Analog normally isn't used for DTS DVDs or Dolby Digital DVDs.

The first digital standard connection for DVD-A and SACD transmission is 5C/DTCP with 1394, commonly referred to as i.link audio. There will be other standard digital connections that handle DVD-A and SACD, later, like HDMI presumably. But DVD-A and SACD on HDMI is not implemented yet in any chipset and probably won't be in any product sold for well over a year. Even after it first comes out in a product, it may be years before it's in a critical mass of products. The first i.link audio (5C/DTCP with 1394) chips were out years ago. The first products with i.link were sold over 18 months ago. As of a few months ago, only about three major brands sold products with i.link. But two or three more major brands plan to introduce i.link products in the next few months. Currently no budget receiver supports i.link audio.

Needless to say 2 channel analog will continue to be around and supported. So will digital optical and digital coax for stereo CDs, DD DVDs, DTS DVDs etc. Similarly, 6 channel analog will continue to be supported for DVD-A and SACD, and co-exist with i.link audio (5C/DTCP with 1394). Likewise i.link audio should co-exist with HDMI v2 if and when HDMI appears. They should all co-exist like with video, where s-video and component and composite video coexist.

The 5C/DTCP standard allows protected transmission of copy-protected material. Five companies, Hitachi, Intel, Matsushita, Sony and Toshiba prepared the "5C" Digital Transmission Content Protection "DTCP" specification. DTCP is a cryptographic protocol for protecting audio/video content from being copied over digital buses like 1394.

Will

[This message has been edited by Will (edited May 30, 2004).]