What sort of cable should I use for digital connections?

Will any analog audio cable work for this?

One should avoid using analog audio cables for AES/EBU digital audio if you have the choice. Use purpose built proper AES/EBU digital audio XLR-to-XLR cables instead.
Anyone with a soldering iron, some wire and connectors, can easily assemble a functioning audio cable for just about any application, but even though both digital and analog audio cables use similar connectors and look quite similar on the outside, for a variety of technical reasons, a proper digital audio cable has different electrical characteristics from analog audio cable.
In analog audio cables, impedance is not of significant importance, because at the relatively ‘low’ frequencies (below 50kHz) in the analog audio spectrum, any reasonably designed cable with excellent shielding and low cable capacitance will work very well for analog audio signal. Proper shielding acts as a Faraday cage to reduce Electro-Magnetic Interference (EMI) and Radio Frequency Interference (RFI). Low cable capacitance results in less high frequency rolloff.

Balanced Analog

Electrical Characteristics: Resistance 40 to 80 ohms per kilometer, Low capacitance 20 to 100 pF/m
Cable type: Twisted pair foil/braid shielded cable intended for analogue audio signal
Connectors: XLR (male) - XLR (female)


Characteristic impedance: 110 Ohm
Cable type: Twisted pair cable intended for AES-EBU digital audio transmission
Connectors: XLR (male) - XLR (female)
Maximum cable length: Determined by cable losses, recommended maximum 100 meters

The digital audio signal frequency range typically starts from about 0.5 MHz and extends to about 30 MHz. The behavior of cables changes as signal frequencies increase. The higher the digital audio signal bitrate, the higher the frequencies a cable must carry. Regular analog shielded cable may not suitable for such ‘high’ frequency digital audio signal and could result in energy reflected back down the cable, which has the effect of degrading the shape of the digital pulses resulting in quality problems in the received audio, or devices not receiving the signal properly. Problems typically gets worse with longer cable runs.
Digital audio cable construction controls the characteristic impedance of the cable during production. The inner conductors is typically stranded copper that may be silver plated. The insulators surrounding the conductors are made from plastic materials such as  polyethylene or Teflon and have the desired dielectric properties at the design frequency range of the cable. The materials and construction influence the electric properties of the cable. The shield is usually made of foil and wire braid either in single, double or multiple layers. The outer insulating jacket is made from PVC or other plastic materials.
In transmitting high frequency waveforms the cable must have the same characteristic impedance as the transmitting device and the receiving devices. Once this is achieved the cable losses per meter, which should be as low as possible, determine how far you can carry the signal. attenuation of cable radiation determines how much electrical noise your digital audio signal will radiate to the surroundings and also how susceptible your system is to nearby electronic noise sources. Good attenuation of radiation will make your AES/EBU interconnection robust and will improve the reliability of the AES/EBU link over a longer distance. In practice, you will not experience any signal quality degradation in AES/EBU audio until your signal quality drops below a certain level. To determine how reliable your transmission system is you typically use a special AES/EBU signal quality analyzers. If you plan to carry the digital audio signal over long distances it is advisable first of all select the high quality AES/EBU cable and then to use these tools to make sure you understand how reliably your system is working.