What's the difference between a digital coaxial cable and a standard rca interconnect?

[Diapason]

I may have asked this before, but if I connect a digital source to a DAC using a standard-issue RCA interconnect cable, is there any reason to expect a difference from a "proper" digital cable? Is the spec different?

[Ciaran]

The digital cable theoretically needs to support a wider bandwidth than the analogue cable, but I'm sure the analogue cable would work. Would you hear a difference? I wouldn't put money on it! The longer it is the more difference it will (would theoretically) make.

[Diapason]

Thanks Ciaran. Using half a bog-standard "in the box" interconnect is giving a more stable signal than an admittedly cheap Toslink, so I'm wondering if I'm missing out on anything.

[hudo]

Digital cable needs to be rated at 75ohm.
Not sure whats rating of the regular RCA interconnect though

[Fran]

A standard RCA cable will work fine, but won't meet the engineering standard for S/PDIF standard.

The "proper" cable will be coaxial - a centre conductor surrounded by a shield that's grounded, and will be impedance matched at both ends. That means the high speed signal that is passed down the cable doesn't meet odd "obstacles" which can cause some disruption and degrade the signal. "Proper" cable would have BNC terminations at both ends, which no RCA cable has, so there's that as well. Whether you'd hear much difference is a whole other thing. You won't do any harm anyway.

[Terry]

Ask your wife.

[james]

I bought a digital cable off a member of this forum a few years ago. He was also selling standard audio cables and I bought some of those also. They were identical. I looked up the company (English) and basically their digital cable was a mono version of their stereo cable. Can't remember the name of the company (highly regarded) but could look it up.

[Diapason]

Thank you, all very interesting I must say.