At what distance are balanced XLR cables needed?

The superior connectiviity of a balanced connection makes it an easy choice--if you have that option. And while Kinjanki makes a valid point, reasonably priced XLR cables are widely available. A well-known manufacturer touts Belden cables with decent connectors for his very pricey gear. If it's good enough for him... Kal's comments are certainly valid also. Try borrowing cables from the Cable Co. The only downside is that they probably have limited choices in the lengths discussed. Blue Jeans Cables might be a good, low-cost option for you. Just my $.02 Good luck!

Kijanki.. And you can pay an arm and a leg for little stones.
Atmasphere, whose opinion carries a lot of weight, has suggested that fancy wire is of little value in balanced interconnects.

I ran a 30-feet Purist Dominus RCA-RCA IC from Aesthetix Callisto Sig line stage to CAT JL-3 amps for a few years and had no problems with noise, radio station pickup, etc. My experience with this one setup nullified many of the theories regularly reported here. You won't know if it a cable works for you unless you try it out yourself.

Atmasphere, whose opinion carries a lot of weight, has suggested that fancy wire is of little value in balanced interconnects.

I value the contributions made here regularly by Atmasphere. But my experiences about balanced and single-ended cable differences significantly differ than his reports here. Once again, don't get too attached to the blanket statements often made here, but rather try many cables for yourself.

Jafox... I also ran long single ended interconnects for many years without problems. And they weren't any exotic wire. I changed over to balanced interconnects simply because I bought some new equipment having this interface.

I trust Atmasphere on this subject not only because he is usually well informed but also because he once provided a good writeup on the subject of balanced interconnects. Maybe he will come by and do it again.

Atmasphere, whose opinion carries a lot of weight, has suggested that fancy wire is of little value in balanced interconnects.

There is a little more to that statement than meets the eye. For example, Ralph indicates that the balanced cable used between his preamps and amps need not be anything more than Mogami cable. The reason being his designs support the 600 ohm standard, something used in pro audio, and thereby controls the interconnect and makes the capacitive, inductive, resistive and other aspects of the cable negligible. Not all components are designed to this standard.

To further clarify, according to Ralph who posted this in another thread I'm a participant in, a low output impedance will mean that the preamp can drive a load of less than 1000 ohms without loss of bandwidth, voltage or increase in distortion. IOW if you can hear differences in the cable between the line section and the power amp, then the cable is not being controlled.