I seem to recall that Kimber cable does not meet Naim’s requirements, and in some cases has caused stability problems, though whether true of theis particular cable & length, and your particular amp I don’t know. You need to check to see if the inductance reaches the minimum Naim recommend and that the capacitance doesn’t exceed the maximum. Those details as required for correct loading of Naim amps have been stated many times on this forum so a search should find, and consult Kimber for their specs.
These are the specs from the website regarding the Kimber 12TC speaker cable. I dont really understand the specifications, could somebody please tell me if this is acceptable for Naim power amps. I’m running the NAP 135s.
NACA5 recommended length gives 56-320pF and 3.5-20uH. That Kimber cable is far higher capacitance, exceeding Naim’s recommended with just 1m, while the inductance would require 39m to reach the minimum. Although IIRC the more recent Naim amps are said to be more tolerant than the classics, I’d be surprised if they’re that tolerant!
Why do you specifically want to spend a lot of money on speaker cables?
I tried my Kimber 8TC with my old NAP250.2. It really didn’t work well at all, sounding poor compared to when I used with a big valve amp, and the 250 got hot pretty quickly. I would avoid using it on a Naim amp if I were you.
I’ve been using the NAC A5 for many years. I had no reason to change however I’ve had good experience with the CHORD Epic XL. They sounded more musical than the NAC A5 although at 5 times the price you would expect them to sound better. However the difference in price isn’t reflected in the performance difference. Having said that the Vertere Redline at just about twice the price of NAC A5 looks an interesting proposition.