Is positive reinforcement why things are sounding better?

But I didn‘t know Wilson speakers existed until I heard a pair.  I had no expectation bias but once I heard them I wanted a pair.  It took me 27 years to finally work up the nerve to spend that much on a pair of speakers.  And over that period of time I never found another speaker that I liked better- or liked enough to buy in place of the speaker I wanted.

I agree that once I decided to buy my speakers, expectation bias continues to urge me to upgrade to one of their more expensive models.  But that is counterbalanced by, 1) Lack of desire to actually change speakers- a lot of effort, time and money, 2) Spending priorities such as needing to eat, and 3) Risk of disappointment that a change will not meet expectations.

@tonywinga your experience matches mine. I too did not know that Wilson speakers existed until I heard the Watt/Puppy 7's at a dealers. Once I heard them I wanted a pair. I kept my W/P 7's for 20 years and eventually upgraded them to Sasha DAW. In my opinion the upgrade was worth every cent.

@tonywinga  , I don't think anyone is trying to say that all percieved sonic improvements are a result of confirmation bias.

"how can you really tell?" ...by listening OP, by listening...

When I bought my first tube preamp, a ARC SP-3a in 79(?) I bought maybe six different sets of tubes for it.  Each had its own sound and I settled on the a Amperex 12ax7. Now I have an SP 9-MK ll that uses 6dj8’s and I basically did the same thing and ended up using Amperex 6922’s in it.

Half the fun of this hobby is trying new things and seeing what hat they do, good or bad.

All the best.