Digital vs Interconnect Cables - Difference?

sometimes you will like the DAC inside the preamp and sometimes you may prefer what came inside your CD player.

I suppose there are a few components that could be considered preamps that have dac, most do not. CD players have dac's.
I use digital rca to bring the digital (1&2) signal from a transport or digital cable box to a DAC (converts the signal back to analog) to a analog rca to the pre/amp. As far as I know a regular rca ic can not transfer a digital signal.

Digital cables come in 2 varieties... 75 ohm rca connectors and 110 ohm xlr connectors.

They are used for connecting 2 digital components, mainly to a dac, from a cd or dvd transport.

Any connections between sources and preamps or preamps and amps would be via analogue interconnects

You can use any analog (RCA or XLR) cable in the place of any digital (RCA or XLR) cable and vice versa.

Digital cables are usually just one cable, so you would need two of them for an analog connection.

XLR connectors would need to be the correct pinout, (most are the same).

I have done this many times. It might not be the correct/proper impedance match, but it sure won't hurt anything.

Can someone explain the difference between digital and interconnect cables?

A digital cable is a form of interconnect cable, that is designed to conduct digital signals. Another form of interconnect cable is one that is designed to conduct analog signals. I believe that your question is intended to address the differences between digital interconnect cables and analog interconnect cables.

Both analog and digital interconnect cables can be had in balanced or unbalanced configurations. Balanced cables utilize XLR connectors. Unbalanced cables usually utilize RCA connectors, although BNC connectors (which are superior to RCAs) are used occasionally.

Balanced digital cables have 110 ohm impedances, and are NOT coaxial. Unbalanced digital cables have 75 ohm impedances, and are coaxial.

The impedances of analog interconnects may or may not be specified or well controlled.

As Mofi indicated, any of these cable types will function in both analog and digital applications, as long as the connector types match the connectors on the components that are being connected.

IMO, however, using an analog interconnect to conduct digital signals is poor practice, and stands a good chance of being sonically non-optimal. (In saying that, I'm assuming that the manufacturer does not specifically indicate that the cable is suitable for digital as well as analog applications). Digital signals involve vastly higher frequencies than analog signals, which means that a poor impedance match will degrade waveform quality, which in turn may (depending on many system-dependent variables) degrade sonics.

Using a digital interconnect to conduct analog signals stands a good chance of working well, IMO, but depending on the design of the specific cable MIGHT not work quite as optimally as a similarly priced cable that is intended for analog applications. There are several possible technical reasons for that, depending on the specific design, although I suspect that in most cases the differences, if any, would be minor.

Is digital for connecting CD/SACD transport and DAC?

Yes, that is one application of a digital interconnect cable.

How about the cables between CD player and pre-amp - Interconnect or digital cables? And between pre-amp and power-amp?

Those connections usually involve analog signals. See my comments above.

Regards,
-- Al

After Al's eloquent posting above, I wanted to clarify my comment.

Can you use an analog cable for a digital cable and a digital cable for an analog cable? Yes, you can, (assuming the connectors are the same). Should you, no probably not, but in a pinch, no harm will be done...other than perhaps a sonic degradation of the signal.

You should always use the proper cable for the application.