I went to a Sony outlet in Massachusetts and found a refurbished DVP-NC655P DVD player. It plays CD-R/CD-RW/DVD-R/DVD-RW, MP3 CDs, and VCDs. It has coax and optical digital outs. It has a 5-disc changer. It has some nifty video features for sharpening the picture, plenty of controls and display options (showing all angles at once), and a decent remote. It has progressive scan output. It's fast and works well. I'm happy with it.
The only thing that sucks about it is that it has a volume control, but only has codes for about eight brands of receivers; so I can't change the volume with the remote control (please don't tell me about all the great universal remotes out there, I know :-).
So I went to Radio Shack to buy a coaxial cable for the digital audio, and the 40-something-ish manager asks if he can help. I don't want to spend time looking (it takes me a few minutes to get my bearings in the cable section), and I know what I want, so I say I need a coaxial cable for digital audio. Simple, right?
He asks what length, I say six feet. He hands me a six-foot coax cable such as for cable TV. No, for digital audio, I say. It's slightly different, and has a different connector. He says oh, the only way to get a true digital signal is with optical cable. No, I assure him, the coax connection sends exactly the same signal. He assures me that no, the DVD player will convert it to analog first, and then send the audio signal.
I literally laughed at him (not intentionally) as I tried to explain that he was incorrect, that this was not a regular RCA audio cable, but a coaxial cable with an RCA connector, and it transmits the pure digital signal, but he wasn't budging.
But I do like my new DVD player.
Re:Coax is better!
pudge on 2002-10-20T02:05:30
I've heard all sorts of things. I've also heard that you can get a perfect signal from a coat hanger, that there is good error correction and retransmission, and that there's nothing to worry about.Re:Coax is better!
merijnb on 2002-10-21T09:17:33
As far as I understand the difference is very subtle . The digital signal on the coaxial cable is transmitted with a clock signal in the transport. The optical is not timed. This does not matter for DVDs as its encoded signal has an internal clock, so whatever transport is used, the DA converter always uses the internal clock to properly time the decoding.
CDs do not have this internal clock in the encoding, so clock skew on the CD can be transported over optical, but not over coaxial. This only matters if your CD plater is iffy and produces clock skew to begin with. So in the general case, there is no difference. And then all your components need to be very good to detect the difference.
It is very interesting to test this out. I have a CD player with analog out and digital out, as well as a DVD player with both. My amplifier can take coaxial and digital inputs for both, so I have three DA converters that I can use to decode CDs and six transports.
In the end my listening ears preferred the DA from the (very good) CD player over the other two, the amplifier was reasonable but not great and the DVD was downright awful with CDs. So now I am hooked up with analog RCA/tulip cable from CD to amp and digital optical from DVD to amp. The DVD is just a reader for the audio, it does a great job on the video decoding though. The amp does the DTS/DD 5.1 decoding and is great for disturbing the neighbours.
