seanadams;396050 Wrote: > If you're willing to overlook clock noise then the unidirectional, > single conductor that comprises s/pdif is really quite elegant, and > makes it both easy to use and inexpensive to implement. You will never > see word clock connections on mass market equipment because it requires > manufacturers to provide additional connectors, and users to connect > another cable to them. This has not only cost implications but > significant real estate requirements on the crowded back panel of an > a/v receiver. Besides, if you are connecting a standalone DAC and care > about jitter, then you are already miles outside the mass market for > audio gear. > > However, as we move away from media which are designed to be read in > real-time (CDs, DVDs) and towards home networks, internet streaming, > etc you will see the issue disappear on its own, as the clocking > inevitably moves towards the DAC in these schemes anyway. But even > then, consider that A/V receivers in their present form (basically they > are just "input selectors") would have to be completely rethought, > because that functionality has no place in a fully networked scheme. > > There is a lot of legacy behind the design that s/pdif delivers in > real-time. Even CDs were designed more like LPs than hard drive > platters, in that their tracks are laid out in a spiral to allow the > laser to track them continually from start to finish. There is a deeply > ingrained way of thinking about information transfer that it necessarily > occurs at whatever rate it's being consumed (technically the term for > this is "isochronous"), and only with recent, powerful PCs, cheap > packet networking, hard drive storage etc can those assumptions finally > be let go. > > But it will still be the case indefinitely for other technologies such > as broadcast/satellite delivery where you have a unidirectional, > one-to-many transmit path with no possibility of doing flow control. In > the video world the possibility of internet delivery replacing broadcast > has been "just around the corner" for a long time - it will happen (eg > AT&T U-verse, Apple TV, etc) and maybe soon enough we'll just have > ethernet plugs in the backs of our TVs instead of the ridiculous HDMI > interface. > > Anyway the point is, the designers of s/pdif didn't deliberately choose > a "sub optimal" scheme. Maybe they were unaware of the problem of jitter > (I could believe that actually) but just as easily they could have > considered it and made a decision that it was outweighed by the cost > and usability advantages of using a single conductor. We are getting to > the root of why high-end audio is such a special niche.
Sean, I can see I've touched upon a topic to which you've already given considerable thought. Although it's off topic for this thread, dare I ask what it is about HDMI you find ridiculous? I find it ridiculous myself, for reasons such as the cumbersome HDCP handshake, the flimsy physical connector, etc. But I suspect your reasons may be more related to data transfer, about which I know nada. By the way, at the CES show this year, I saw a few TVs that had Ethernet ports, although it was unclear what kind of content they would handle by that path. And there are some AV receivers and preamp/processors already on the market (such as the Marantz AV8003 and several Denon units) that have Ethernet connectivity for handling networked music from a DLNA server. I looked pretty seriously at buying one of those receivers, but their networked music capabilities were limited, with clunky user interface, minimal audio format support, and the like. The makers of those devices clearly tacked on networked audio as an afterthought, rather than a fully flushed out implementation. So, it's still a Squeezebox for me in the home theater. ;-) It might be nice, though, to be able to use that big screen TV as a display for the Squeezebox. Then, of course, you'd need to deliver both audio and video to the AV receiver, in which case, it would probably use (eek!) HDMI. -- TiredLegs ------------------------------------------------------------------------ TiredLegs's Profile: http://forums.slimdevices.com/member.php?userid=6201 View this thread: http://forums.slimdevices.com/showthread.php?t=50147 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
