New expensive power cord for amp and no change in sound?

I felt my X250.8 and XA160.8 Mono Blocks sounded better with Cerious Matrix power cords than the included ones...I do find that power cords are more unpredictable than other cables and cords...Pass does include good power cord, and I use them in secondary systems...though Pass has a reputation for not recommending upscale cords and cables, many articles say they use expensive Silent Source cables and cords in their listening rooms and in shows...in an interview, Nelson Pass said he very much liked a pair of speaker cables that Ray Kimber loaned him, until he found out they were $54,000 a pair...

I find that used power cords hold their value extremely well...I've bought and sold some fairly expensive cords, and generally ended up spending less than if I had bought parts to make my own (which I could not actually do)...we all have different preferences, budgets and priorities, and there seems to be too much critical, insulting, demeaning statements about others choices...and there are certainly some inexpensive products that sound great, and expensive ones that don't...but I really don't think there are very many who just want to spend lots of money on products they don't actually like....

I prefer my Pass XA160.8 (as well as my previous Pass X250.8) with Cerious Matrix and Lumniscate  power cords. According to Stereophile (and others) Pass Labs uses Silent Source power cords and cables to voice their products and present them at audio shows...

often, if it sounds "different" it will sound better to some and not to others...and yes, many here have done blind tests, but to decide for ourselves, no need to "prove" to others...no one here really wants to spend money and get nothing in return...though some seem to think many here do and are not able to make reasonable decisions for themselves...