As for @atmasphere, he simply won't accept that his opinion that the only proper way to build a balanced component is to make it consistent with the AES48 standard is simply his opinion. It's one that most of the high end community has rejected but he disputes that too, arguing that maybe they've never heard of the "standard." Those are the simple facts and I'll grant him the last word.
Ralph's issue is confusing his opinion with fact. No more, no less.
@cleeds Please read this thru to the end; you might see there's another explanation.
You might have to be a member of the AES to view this document:
https://www.aes.org/publications/standards/search.cfm?docID=44
At that link:
Abstract: This standard specifies requirements for the termination, within audio equipment, of the shields of cables supporting interconnections with other equipment, taking into account measures commonly necessary for the preservation of EMC (electromagnetic compatibility) at both audio and radio frequencies. The shielding (or screening) of audio equipment, cables, and microphones can be critical for EMC. The improper connection of these shields can cause common-impedance coupling in equipment.
You should be able to see something at the link on that page entitled: 'Downloadable Preview'; on page two at that link you'll see an interesting list.
Opinion vs fact... where your argument falls apart is where you say the 'high end audio' industry rejected AES48. So hang with me just a bit as there is some history first:
You have to jump thru some hoops design-wise in order to support the standard. Traditionally in the 1950s when hifi was getting started no-one thought there was a need since home audio devices weren't built to the same standards as recording/broadcast equipment, no-one thought there would be a need for long interconnect cables and no-one thought RCA interconnect cables might influence the sound if kept short.
Back then, to drive a balanced line you needed a line transformer and they cost about as much then as they do now ($500-$1000/channel) once adjusted for inflation.
So traditionally all home audio has used single-ended connections. Please keep this in mind.
Its that issue about an output transformer that has most tube preamp producers stymied about driving balanced lines. They cost a lot so will raise the price of a 'balanced' preamp by $1000-$3000 depending on how the manufacturer sets pricing. You could use a solid state circuit that's a lot cheaper but tube preamp producers and their market tend to disdain that idea. Or you could use our patented method but we're a small player and to this day a lot of the high end community doesn't know who we are and if they do, don't realize that we are more about balanced line than we are about OTLs (IOW we're still known for OTLs despite the fact that our preamps have traditionally been our best selling products). If they do know this about us, the other problem is in high end audio designer's don't like to use ideas 'that weren't invented here'.
Add to that the simple fact that many are simply ignorant of AES48 and you have a nearly perfect storm. I knew there were standard practices for balanced line back in the 1970s but I didn't learn about AES48 until about 10 years ago (it was codified about 2005); and yet we were the ones that pushed harder for balanced lines than anyone else in high end audio worldwide with the first fully differential balanced amps and preamps made back in the 1980s.
So from my perspective its hard to see yours. We influenced ARC to do balanced line; Dave Gordon (who might still be at ARC) and I were visiting the same dealer in Studio City CA back in the early 1990s after CES and he saw that we had figured a balanced connection between a tonearm and preamp. He asked how we did it so I sent him a copy of our MP-1 preamp owner's manual which details how its done. A while later ARC produced their first balanced phono section, later discontinued as they found out that dealers didn't like that because they had to change a cable to play it and that sort of thing could cause a customer to walk.
I think the rejection argument isn't quite right; here's something we've not yet discussed:
When you have a balanced preamp that does not support the standard, it will play nice with single-ended equipment (in particular, a balanced preamp driving an amp with a single-ended input; this because single-ended and proper balanced operation are mutually incompatible, which means if you try to hook one up with the other you can get a buzz problem) and will also cost less.
Occam's Razor suggests that between two explanations for a given situation, the simpler one is probably the correct one.
So your explanation that 'high end audio has rejected AES48' needs some nuance. I'm also thinking my idea of ignorance isn't quite correct either (although I know of examples where that is clearly the case).
I think the simplest explanation is AES48 is inconvenient because it complicates equipment compatibility (solvable but can be an additional hoop to jump thru) between single-ended and balanced, which means dealers will have objections (this is one we've dealt with a lot) and its more expensive. Both of those are money issues; that is the simplest explanation.