Digital vs Interconnect Cables - Difference?

Good question but you are going to get a ton of responces. Although an awful lot of video cables as well as audio will work as a co-ax digital cable the actual spec for a co-ax digital cable is 110 ohms not the 75 ohm viseo cable spec. It's not as simple as all that since the RCA connector used is not a 110 ohm plug either. IMO these factors lead to LOT of debate as to what cable works best for digital. I myself am a big fan of synergy so no matter what you buy make sure you can return it. IMO recommendations on cables are much more valid if they come from someone who has heard them on the same make and model of equipment that you yourself are using. Do you have your Digital source and DAC yet?

To answer your first question last, there are many ways to transfer digital signals but the most common are probably digital co-ax with RCA ends so they look like a conventional audio or video cable, optical digital with a Toslink plug which looks nothing like an RCA plug and IMO is a crappy plug and HDMI cable.

As far as what type of cable to use between a CD player and preamp, assuming you have both options, I would try it both ways as sometimes you will like the DAC inside the preamp and sometimes you may prefer what came inside your CD player.

Hope this helps.

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