jayctoy, you will find a lot of discovery and joy by actually trying things, as opposed to the audiophile who lets preconceptions block such activity. That is why I have said for years that the greatest impediment to building an audiophile system is the audiophile!
I had to smile when I read your comment, "I decided there must really be something that I don't know regarding using different cables, ok this morning, I replaced one of the power cord of my musical fidelity monoblock amp, fromMIT to Pangea, Result, more dynamics , more balance, Icant believe it, but it works, on Friday I will use different speaker cables on the left side of the Andra.see what happen..,," and I thought, "Well, of course!"
It seems you have been a cable skeptic, or at least a power cord skeptic for a while now. So, how does it feel to discover that all the time power cords confer a very noticeable difference, and you were missing out on it by refusing to try? Some guys get upset that they have been resistant for decades, only to find out later in the game that cables made such a difference. They have to accept the fact that for no other reason than their stubbornness they have heard closer to mediocre sound versus what they can get when they work with cables. Thankfully, I conducted comparisons about three decades ago and have had a lot of experience with real world changes to sound with cables.
If you really want to hear what cables can do, work with sets of them. If you are impressed by what one power cord can do, and I understand perfectly your description of it, then consider how much change can happen when sets are compared!
Congratulations on actually trying it. Now you will have the ability to get much more out of your audio system. Now you are on your way to building a better audiophile rig. :)
Discovery is a wonderful thing!