@lwin :

I do get frustrated by those who insult others on this forum. If a power cord ,fuse etc. makes a positive difference in your system and you want to share your experience with others you shouldn’t be subjected to ridicule. I have gotten some great information on this and other forums.
 I trust my ears and palate but I appreciate the opinions of others. We are all different to some extent thank goodness or the the world be a really boring place.

Great post. Well said ☝️

All I am saying is that I don't know to what extent the differences I hear and taste are differences that truly exist and to what extent they are manufactured in my head, entirely unbenown to me. 

So, how do you make your purchasing decisions, if you don't trust your ears & senses?

@clearthinker : (what a "relevant" username!):

He suggests that because confirmation bias is not present in wine tasting,

The result of course is rubbish. Confirmation bias exists in all fields

In fact the record shows that confirmation bias is present in wine tasting

legions of published accounts of confirmation bias

they tasted was the real thing - pure confirmation bias.

save to confirm confirmation bias is alive and well

This must have been the single post with most "confirmation bias" mentions. Which is real. But, it is real and true in your camp too, not just for people who report hearing some positive difference, have you ever thought about it? In other words, if you folks think everything sounds the same, they WILL sound the same. Even if you base your "listening tests" by reading stuff in the internet.

In the years I have been reading audio forums, I have come to believe that "confirmation bias" is simply a phrase naysayers throw in your face if you post something making a difference, anything making a difference. I.e. "this cannot possibly work, you are imagining things ---- confirmation bias!". Subjectively, the phrase / phenomenon has lost its true meaning to me. Unfortunately.

I should test my brother-in-law sometime.  He and my sister actually named my niece after a favorite wine.  I could track down someone that could recommend the most similar inexpensive wine and see if I could get my sister to pour him a glass of it on the down low and see if he would recognize that something was off.

IMHO this is called “tricking”, not “testing”. A test would be if you actually told him what you were trying to accomplish, and put together (with his permission) a blind test for him which you would administer. It’s also fair to your BIL