Home Theater: Analog and Digital audio cable question - impedance

[radiowhiz]

Hi All,

Can someone tell me if the standard stereo audio cables terminated with RCA jacks used for left and right stereo channels can be used for connecting digital audio out between say DVD player and A/V receiver (using one just one of the physical connections (red or white) ? Essentially are these standard audio cables interchangeable for analog and digital audio home theatre applications? Are the impedances the same?

I thought I had read somewhere that the digital coaxial cables are 75 Ohm cables and the standard red/white audio coax cables are a different impedance??

Any input would be greatly appreciated.

Thanks,
radiowhiz

[piano632]

It's not only the impedance factor, but analog audio and digital audio operate at different frequencies, so the cable may not be designed to carry the frequency range of digital audio. If you have a RCA composite video cable, that would work much better since digital audio operates at about the same frequencies as analog video (and the impedance is the same @ 75 ohms). In fact, I use a digital audio cable as a composite video cable in my system.

[radiowhiz]

Hi there,

Thank you for the response.

Good point re: freq. response too. Your response triggered another question ... For component inputs (Y, U, V), what are the cable requirements? I've noticed that cable vendors will market specific component cable sets but I suspect there is a tendency by AV end users to reuse existing composite/audio cables if they have them kicking around because they supply 3 bundled coaxial cables with RCA terminations as well. But as I vaguely recall, component cables are carrying color differences and may be carrying mixed signals (AC on a DC bias) so what is acceptable for these connections?

Thanks in advance,
radiowhiz

[edDV]

Coax S/PDIF audio and analog component (YPbPr) all use the same 75 ohm coax as analog composite (yellow). Analog component YPbPr comes in standard definition (under 8MHz analog bandwidth) and high definition 720p/1080i/1080p (15-60MHz analog bandwidth). High definition application needs better quality (e.g. double shielding) and will video quality degrades faster as cable length increases.

[olyteddy]

If it's a digital signal you're trying to pass, you can try any kind of cable. The result will be either acceptable or a failure. There's no 'distortion' involved. Analog signals, OTOH, can have varying degrees of success and cabling parameters can cause distortions.