I just have to comment on the article’s introduction: “…continual and perpetual difficulty of hooking up audio equipment without suffering through all sorts of bizarre noises, hums, buzzes, whistles, etc….”.
In forty years of using single ended interconnects I have never experienced any of these symptoms, ever. I tested dozens of interconnects and components over that time.
I’m not refuting the paper. I’m just saying it is overstating the problem.
I went through a major upgrade a few years ago and did an A/B comparison on my audio equipment and found virtually no sonic benefit, but the cost was 2x to go to XLR. So for me that was $5K —> $10K. I had to think long and hard about spending $5K for no sonic improvement. In the end, I went ahead and did it. It gives me peace of mind, and XLR are becoming much more common… and I can afford it. if I was younger and was stretching to get the very best components I could afford… I would have just stuck with RCA… and upgraded when I could afford it.