Copyright ©1996, RF Specialties Group.
Many
radio and TV stations are using less expensive consumer grade CD players (and
other consumer audio gear) in their studios lately. And why not? The audio quality
exceeds the capabilities of most transmitters and these units can be replaced
quickly, easily and inexpensively by anyone who can plug them in. A few extra
minutes spent wiring the unit properly will make a world of difference, particularly
if EMI/RFI is a problem.
Most console manufacturers recommend using balanced audio sources for the best quality sound. While it's true that a balanced source can yield better frequency response, an unbalanced source can provide excellent quality sound too. Some manufacturers have designed consoles with inputs that will accept either balanced or unbalanced sources (as is the case with Fidelipac's MX Series) or dedicated inputs for low-level unbalanced sources (as is the case with Autogram's Minimix consoles).
Stick with shielded pair wiring when connecting consumer grade gear. Instead of connecting the shield to the sleeve (-) of the plug on both ends, leave one end floating. The connected end (usually at the console) provides a path to ground for stray noise and RF which can degrade audio quality. Occasionally better results may be obtained by grounding the shield at the source rather than the destination.