Optical vs. Coaxial Digital Connections

Q: Between optical and coaxial, which connection is going to give the better sound quality, and why?

A: " Better" is relative. In a harsh environment, optical may have advantages. By "harsh" I mean:

In most cases, the above conditions would result in negligible impacts on the signal quality since the signal being transmitted (PCM or bitstream) is sampled at low frequencies (44-48KHz) and thus are more immune to noise impairments.

However, using optical cables can minimize the potential of the above mentioned problems and thus may help to reduce common mode noise. The only negative about using optical cables is the connection is not always as secure as a coax one, and can sometimes be compromised easily by moving components frequently. In addition, optical cables are usually more expensive than coax ones.

Bottom Line: Using optical cables for your digital connections may help minimize susceptibility of coupling RF noise into the line and reduce loss for long runs (10 feet or more). However, optical cables tend to be more costly and sensitive to abrupt external forces, which may potentially weaken the connection over time. In any event, either connection method should yield excellent and comparable results in most cases.