Recommendations for warm cabling almost universally default to Cardas Golden Cross, although I don't believe it's solid core.
I can also recommend Gregg Straley's Reality Cable speaker cable. Have you tried it? I wouldn't characterize it as warm, but neither is it bright. It transmits everything fed to it, but it's free of etch, grain and glare in my system.
It's tough to find "warm" and "detailed" in the same cable. "Warm" tends to also include "reduced detail".
I can also recommend Gregg Straley's Reality Cable speaker cable. Have you tried it? I wouldn't characterize it as warm, but neither is it bright. It transmits everything fed to it, but it's free of etch, grain and glare in my system.
It's tough to find "warm" and "detailed" in the same cable. "Warm" tends to also include "reduced detail".

