Upgrade rca cables

Since you are using Prima Luna and Musical Fidelity, I would contact Upscale Audio for a recommendation.

@ghdprentice interesting. Carbon is not metal though is it?

And it’s conductivity cannot match copper os silver.

I use Kimber Carbon interconnects in my system - copper conductors with carbon infused polymer and teflon dielectric.
They do sound ridiculously good. 

I have a Primaluna preamp, Primaluna monoblock amps, a Marantz SA-10 CD player, and Sonus Faber Olympica Nova V speakers. Primaluna electronics have a somewhat warm sound. Nordost cables have a very open sound, and they work well with warm sounding electronics. I started with Nordost Heimdall cables, but I liked them so much that I upgrade to Valhalla and Odin level. If you like the way that Mad Scientist cables sound, then you should go to a dealer and listen to Nordost so that you can make a comparison. I've listened to several cables, and Nordost cables work much better in my system than other cables. I've never heard Mad Scientist white cables, and I'm unaware of any reviews by anyone whose opinion I would trust.

The conductivity of carbon depends on the form... but graphene is very close to metals. 

They are not carbon or graphene. Made from a metal