XLR or RCA?

My experience has been that if the equipment is fully differential, properly implemented, an XLR cable is a real bonus as the cable is sonically transparent. I've run some very good RCA cables, and in one application where the output of the source and input were fully differential, I could find no meaningful difference between a set of Mogami cables and anything of any price upwards of $1K. And I set that limit of $1K not because I think cables above that can beat the Mogami, it's that I just have no interest in spending more on cables.

And as noted, just because there's an XLR output doesn't mean it's better. I have a Pass Aleph Ono phono stage and I asked the kind folks at Pass which I should use into my Pass INT-150. The answer was- use the RCA

XLR any day for me. In my system, when used between my preamp and mono amps, it eliminates hum which is ever present when i use RCA cables.

Yes, you are right, full benefit is obtained if the system entirely is wired using XLR

I used a new pair of balanced cables into a decidedly non balanced but XLR friendly power amp, and they sounded like crap. Seriously...replaced them with much better XLR cables and all is well (although in this case I could be using single ended cables I do prefer the XLRs anyway). I noticed some substantial differences between brands of ACTUALLY balanced cables when mixing sound with headphones from a live feed (TV show production). Even with truly balanced signals I can say that better cables can sound much better. Who knew?

****************02-23-14: Ferrellms
For long runs, rule of thumb being 50 feet, XLR will pick up less interference (less noisy), but in general there will be no real (measurable), as opposed to perceived, (subjective) difference. *****************

This is nonsense. It is an intentional distortion of the following statements from a whitepaper published by Rane, Inc. (in coordination with the Bill Whitlock of Jensen Transformers, Inc.) used by equipment and cable manufacturers who do not offer differentially-balanced products:

"Since the input stage is not balanced, induced noise on the signal conductors is not rejected. If you must use an unbalanced input, use as short an input cable as possible. This reduces the induced noise. There's a reason it's hard to find and buy unbalanced RCA cables longer than 12 feet. Figure 5i shows both ends of the cable shield connected to units with chassis-grounded shields. If the units are far apart, the chance of the shield currents inducing noise on the signal conductors is greater. Keeping this cable very short reduces the shield current and therefore reduces the noise that is not rejected by the unbalanced input stage. Most systems may require disconnecting one end of the shield for the Figure 5i case. Even a small current in the shield may prove too much for an unbalanced input stage."

and this:

"Fully unbalanced systems do not provide a 3-conductor connector to enable proper use of a shield. In the unlikely event you run across one, use the wiring in the fourth column (Figure 5m-p). Again keeping cable lengths short will reduce noise problems, with or without a shield."

Read the entire whitepaper for yourself:

http://www.rane.com/note151.html

Further accurate information on the benefits of the correct implementation of differentially-balanced circuits can be found on the pdf link at the bottom of the page of this link.

Dave

@ Dlcockrum, Hi, The last part of your post that your white papers said, Again keeping cable lengths short will reduce noise problems, I have been saying this for the last 25 years!, the fact of the matter, I have said this recently to a few members, It does not matter what I tell them, They believe some manufacturer that says other wise, or believe someone they know, It's to the point of, what do I know, right?, LOL!, I use 6ft speaker cables, all XLR interconnects are 1-meter length, no rca cables at all, all componets are true balanced from in-put to out-put that I use, been doing audio for 35 years, this a very long time, again, what do I know!