Question about weak link

Hello All,  I just got a bunch of new gear and don't know where to start looking for a problem.  I am no longer hearing very high frequencies, such as bells or chimes in my music, the way I did before my "upgrades.  They sound weaker in volume and veiled in clarity.  I went from acoustic zen satori shotgun cables feeding Martin Logan spires to synergistic research atmosphere level 3 cables feeding Martin Logan Summit X.  I also switched from a Spectron musician amp to a PS Audio BHK 250 amplifier.  I would appreciate any feedback to my question of which of these changed components is likely to have the biggest impact on the reproduction of the highest frequency sounds.

Sorry if this is a simple question; I'm ignorant about electronics but a stickler for sound.
rustler