Hi to all those who contributed to this post, and to everyone else interested.
I promised to update on the system once finalized. Gryphon Mephisto Solo have been purchased, all components have run-in well, even if with hi-end it can improve over a year or more sometimes. The Mephisto Solo do just great, even if some other amps out there could have done better, but who can try them all !? Powerwise, they do not scare the Westminster at all, which play very well low and loud alike. Those Gryphon are just totally straight amps, no bull, no flaws, no musical preference, no lack of nothing, whether it be power, resolution, balance of tones, timbre quality or dynamics. They are just very slightly on the warm side, as i like it. On a scale from dry/sterile to very warm/creamy sound of -10 to +10, I would give them a 1 or a 2.
The sound is as perfect as i have ever been able to hear so far in my life. Cannot really describe, but just say that it sounds complete and glorious, with real moments of emotions, tears and breathlessness. The instruments vibrate so naturally each in their own acoustic nature and space and altogether at the same time, you are fully taken up in the musical scene.
Everyone visiting me lately, friends, family and mostly audiophiles, have had more or less the same comments: "it's not just music, it's an experience" or "I kept wondering and asking myself what I had just heard after getting back home, and couldn't listen to my own system for a few days before my ears got accustomed to it again".
I must say that I am quite proud and satisfied, and yet there is improvement to be made at a later stage for the room and main power line, which are really not up to the system.
It has been over a year since I started this audio system, the journey has been very interesting, and fortunately fulfilling as well, so i am grateful since i know how much our audio mania can be disappointing sometimes.
The complete system will soon be uploaded on the "virtual system" as requested by some of you.
