Balanced versus single ended

The issue goes beyond simply the use of different cables as the "standard for balanced line operation" that Ralph often discusses focuses on how audio equipment is designed with respect to grounding and shielding as discussed here.

Could there be sonic differences based solely on whether the equipment is designed to be balanced or single-ended, probably, but how that single difference would affect the sound we hear is something I couldn't predict.  If implemented properly, the balanced gear should be have less noise.  However, it has not been my experience that fully balanced equipment is immune to all facets of IC cable design such as wire gauge, geometry, shielding, connectors, and materials,  but then IME most cable changes are subtle not revelatory, so YMMV.

Certainly, long runs, if equipment offers, use XLR to protect from the added potential of problem(s). But, even a long run at home, really not the same need as a swarm of this and that in commercial setups.

Short runs, home audio system, why?

One clear advantage is the snap in locking connector. 

For stable matched secure contacts for L and R, I changed all my interconnects to locking rca connectors, and use XLR/RCA from my Sony CD player's XLR out, just to compare. I cannot hear any difference between it's XLR out or it's RCA out.

I don't really have a strong opinion in an otherwise well functioning home whether you go with XLR or RCA, but I will say that if you build your own, Neutrik has silver contact XLR's and Parts Connexion has a line of pure silver, balanced IC cables you can combine to make outstanding / end game interconnects for a lot cheaper than you'd buy.

I humbly submit that it really depends on the design of the preamp and amp. But that is just from my own experience and without any engineering background. It always surprises me that so many reviewers claim that SE is just as good, and how many reviewers seem to keep only SE IC's on hand. 

As an owner of an ARC Ref 6 and Ref 80S and Ref 150 SE I know that Warren Gehl and Co strongly suggest running balanced with the very best IC's you can afford. I conducted listening tests with a wide assortment of balanced IC's at all price ranges and heard huge differences. I settled on Cardas Clear Beyond. 

XLR cables cost more… often a lot more. If I was relatively young I would go with balanced… component design is headed that way. But if I was on a budget you can save money on single ended. But as has been pointed out to be sure with your components, you have to try to be sure.

I tend towards being a cable denier, but I have never seen XLR cables that attract the multi hundred t multi thousand dollar figures like RCAs can.

It gets difficult when one has say, an XLR phono stage and RCA based amp and preamp.

Starting new I would agree that using XLRs would be a good choice.

Anyways, my question is: has anyone ever thought that single ended sounded better?given the 2 options. Im only referring to a truly balanced connection

My 30+ year old XLR based phono stage did not sound as good as my 10 year old RCA phono stage… but that did not have a lot to do with the RCAs or the XLRs.

I suspect that the Benchmark, Atmasphere (etc.  etc. etc.) amps that are balanced would sound better than my amps. And they also measure better.

But I would not hesitate to run an RCA based preamp into them even if I had to use an XLR to RCA adapter.

One would probably need the same gear as balanced or RCA to make a determination, and I have seen at least preamp show more distortion products with balanced than with RCAs, so it is likely equipment specific??