"Expectations create reality. If you expect some thing to make a certain kind of change, then thatʻs what youʻre looking for and will likely get."
This is, of course, only partially true...we DON'T always get what we expect.
I recognize that I - like most Homo sapiens sapiens - am subject to expectation bias, but I am equally confident that the bias does not define my reality. I have owned a DAC, a tube buffer, a turntable, and a high-end EQ that I removed from my system due to sonic shortcomings within a few months of purchasing them. I certainly expected them to sound great or I wouldn't have purchased them. In two of those four examples, I returned to the previous piece of equipment I was using, and in the other two I just removed them from my chain, so I didn't replace them simply because I "expected" some new toy to sound even better.
So I was not "bound" to loving gear I owned just because I expected it to be great.
Nevertheless, as I mentioned several posts up, when I added the Pachanko Constellation Mini SE server with Stellar power supply to my system (running Roon as configured by Pachanko), I was thrilled by the improvement. It was far greater than I expected - probably the greatest single-component improvement I've ever made - and my delight has continued.
While I have a physics background, I cannot explain with confidence why a server should deliver such sonic gains (especially as I was also running Roon with my previous components). However, my experience mirrors that of others who have installed high-end, purpose-built music servers: somehow, pre-DAC digital componentry does make a difference.