Are you using balanced connections where possible? I noticed a big difference from Transparent Music Link RCAs to Balanced connections - there is a few db in signal strength gained.
Regarding high end versus quality - I'm currently evaluating upgrading speaker cables. My amp is a McIntosh MC 302 and my speakers are Sonus faber Olympica Nova Vs:
Incumbent - Blue Jean Cables Canare 4S11
Replaced Audioquest Rocket 33s.
Auditioned
Kimber Kable 12 TCs - No go...overall sound seemed to was 'compressed' and when it wasn't high's were harsh and the bass was muddled.
Kimber Kable Bifocal XLs - Still evaluating and the cost is a consideration - Good dynamics and range but not sure if they are worth the money. I
Next auditions may be Nordost or Transparent Supers.
Good luck and share your experience