I am glad someone has a different view than I do and says so in a very tactful manner, and I honestly after all these years can admit that maybe it was thought to sound better and now want to do more A/B blind testing with the amp I have heard the differences in. I will need to repair the amp to do so.....new project.LOL Sonnie, the Zipser test is my fave example of the DBT working correctly. I also agree that the gear ideally will impart no signature at all on the signal passing through it, unless it is meant to, eg EQ.
My current position, based upon many years of designing, building, modifying and servicing a lot of amplifiers of probably every type is that there should be no audible differences between well made units, operating within their specifications. If there is, the unit was not designed well or the perceived colouration intentional on the part of the designer.
As I am not much of a fetishist over brands, I simply want to know if it will perform as I need it to reliably. Many years ago however, I spent a lot of time even testing parts in the amps I designed; would brand A resistor/cap sound better than brand B in this position or that and I tried many permutations of parts as well as topologies. It was not unusual to have as many as a dozen stereo amplifiers on my floor at one time. Because I changed them in/out so often I made a standard connector arrangement for them all so it was one step to change between them. One night after many hours I'd done the last bit of testing and thought I'd made the best amp so far, left it on to soak and went to bed. Next day I listened to some music over breakfast, then went to turn off the 'best' amp to permanently solder in some parts; the music kept playing. I had mistakenly connected in my old mule amp a modest SS Rotel, not the great tube amp I thought I had been listening to for the last couple of hours before bed.
After that I did a lot of testing by close level matching and switching to test myself. Amazingly obvious differences were suddenly not something I'd bet a dollar on. To be sure it wasn't my hearing, I tested others who were sure they could tell differences between just about everything. No one picked such things as a 30yo SS Marantz integrated over a Fisher tube amp for example (I had very efficient speakers with an even Z curve so no real issues there). There were many others too, so it reinforced to me how much our visual perception and preconceived ideas play in what we think we hear.