Balanced vs Unbalanced?

According to McIntosh's manuals with their balanced gear, if your interconnect cables are 6' or under, unbalanced connections are quite satisfactory. However, longer than 6', a 40db advantage in noise reduction is possible. Whether you can actually hear any difference between the two types is subjective.
Here's another one--why is McIntosh the only company to use autoformers, when other companies (i.e. CJ) don't use them? Any sound differences?

While I agree with the above responses, usually the XLR connectors on balanced cables are better. They are beefier and "lock" in place for a more solid connection.

Use balanced if noise is a problem. The XLR is a beetter connection, but requires more circuitry, thus sonically the circuit is beetter with RCA provided the RCA make good connections. Remember, Sheffield lab used coax cable that went from Wiley Chapel about 200ft. out the door to the recording equipment, no XLR's. How much noise do you hear on those recordings? It was shielded cable as well. Jallen

Balance is only better if the signal from the source is balanced from the start, at the digital to conversion. I have owned several CD players & DACs that where that was the case and balanced did sound better. However I have owned a few CD players that had balanced output but the signal was split and inverted at the output stage that does not sound as good as single ended. It depends on the design. For a curve I have all single ended input sources, but between my Pass Labs XP 10 & my XA30.5 I use balanced. I have tried both balanced & single ended & I prefer balanced. Go figure

I too use a system that is balanced, from all of my primary sources, (phono and CD), through the preamp and then on to amps. I do like how quiet it is, but I think that has more to do with the design of the equipment than with the cables themselves.

And I agree with all the others that the connectors (terminations) of XLR cables are better, (because they lock, and almost more importantly, unlock), than the standard RCA terminations. (And I dislike locking RCA terminations, because they tend to lock up after time and getting them to unlock is a pain in the butt.)

However, as has been mentioned by others, only equipment truly designed to operate as balanced, (and not merely equipment that has a converter to take the signal from single ended to balanced), are worth using in balanced mode. Certain equipment manufacturers make sure that their equipment is truly designed from the ground up for balanced operation. (Ayre comes immediately to mind as one such manufacturer, and it has been noted by various reviewers that their equipment sounds noticeably better in balanced versus singled ended.)

My two cents worth.