That just simply is not true. There are components whose effect on the signal is so small that it is totally inconsequential. Too small to ever be audible to a human being or make any difference. And connectors are certainly in that category.
There is a lot of talk and speculation, but so far, to the best of my knowledge, no one has shown any real evidence that the small variations in types of connectors can be heard. It's all anecdotal reports. People are simply reporting what they want to hear. It's mostly confirmation bias. Not a single scientific test.
So until I see some sort of empirical proof of a difference I'll continue to declare that there is none. Science is on my side here. Particularly when I read things about the mass of a connector affecting the sound. There is absolutely no possibility of that happening.
There are a lot of people drinking the cool aid, but no one doing any kind of serious testing. Maybe they really don't want to know the true answer.
Have you ever tried using one cable on one speaker, and another with another speaker? Have you ever tried using a small gauge wire to drive a speaker against a larger gauge? Or is that snake oil too?
From my experience, there ARE differences & they ARE noticable.. but you simply REFUSE to even consider your understanding may be flawed.
I recently made a pair of hand-braided speaker cables, but only had enough wire for one speaker..
The set of cables I made had rolled off highs, causing a severe loss of detail & a dip volume in the upper treble range, esp with cymbal crashes.
The other speaker still using the old cable did not exhibit the issue. even after switching cables, the loss of highs followed the hand braided cables, and went away when the old cable was returned.
So, yes, in my experience, components CAN & DO make a difference, even cables.
You don't need to spend thousands, or even a hundred dollars for something of good quality, as the law of "dimishing returns" will kick fairly quickly, but to immediately deny that there is a possibility any difference may exist is simply unscientific and unrealistic. And the idea you also REFUSE to even TRY something for yourself, shows that no amount of "evidence" will sway you.
I wasn't expecting the differences i heard between these cables, but i still heard them, and it was the opposite of what I expected.
(FYI I don't have tube connectors on my XLS Encores, just the stock binding posts. However, I will be adding a pair to my next order to install & test them for myself. If you want to know the results, get yourself a pair and do your own testing.

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I don't have anything else to say on this matter, I'd only be repeating myself ad nauseum to no avail.
You've clearly made up your mind, & dug in your heels with no intentions to listen or consider anything but what you already believe.