Balanced vs Non-Balanced XLR?

Well the input voltage will be double using the XLR inputs.
If you have too much gain, better to use the RCA.

The current 'fade' of having XLR inputs and outputs is mostly a fad.
If one owrks better than the oter for you, fine.

Few components actually are true fully balanced from input to output.

I use balanced from preamp to my amp mostly because it is 7 meters long cable.

Don't forget about common noise rejection. I use balanced XLR throughout the whole rig even in analogue(swapped RCAs to to 5-din XLR).
The input voltage not always will be doubled. There are components that have XLR outputs that are not balanced. The truly balanced components have standard output voltage and decreased voltage from optional RCA outputs by 4dB so you won't overkill if you use XLR even onto the high-gain amp.
Sonically I can't and won't go back to RCA since i don't have to care much about wire quality.

I use atlas elektra xlr between krell kav500i and technics cd player sl-p2000 and agree with Marakanetz,don't wanna go back to rca.Quality of sound increased,less noise ,more gain

one more thing,I made xlr from rca,just because i found out that rca atlas elektra was balanced cable

The whole perception with Balanced compared to Non-Balanced is that the total over response in signal should increase by 6bd if you using everything Balanced through your whole systen but on top of that it also decreases the noise by 6db. All professional studios use full balance including speakers for that matter. When it comes to your amp whether its a tube or solid state, the perception of sound will be dictated primaraly of your pre-amp and power amp and how much output it is willing to take and how stable the load is. Nordost and Siltech I use all the time to test the differences between them with certain amps and pre-amps, sonically with certain balance cables there is more finer detail, though everybodys hearing is different so you have to hear it in a controlled environment which I do in where I work.

It is not always true that your gain will double if you run balanced- that has to do with the design of the circuitry, even if it is differential.

Usually its to your advantage to use the balanced connection if the source is putting out a balanced signal and the input accepts it. If either are single-ended there usually is no advantage.

But once you hear what the advantage of balanced is all about, you won't want to go back :)

True differentially balanced components eliminate 2nd order harmonics, at least internally. What the speaker does is another story. From a purist point of view, distortion is distortion and the manufacturers that build this way must feel it's worthwhile to nearly double the parts count. It's not a fad.

We don't hear most distortion intrisically. Our ears and brains translate those into frequency anomolies. Personally, I've come to believe that we all prefer or expect some degree of distortion.

The topology is not an end, it's a means to an end. While it's reasonable to assume similar results from similar topology, attributing results purely to topology is idealistic. IOW, you get what you get.

In 'pro audio' the term, "servo-balanced" is often used in relation to conversion to single-ended internally. I happen to own an active crossover that uses this method in an otherwise fully balanced system from source to amps. Balanced crossovers are rare and expensive. Rarely, transformers are still used for this purpose.

There are fully balanced integrated's. Ayre and the Chinese brands, like Jungson, come immediately to mind. And if Emotiva can do it, it's not always a function of cost.

thank you for all response!