Musical Power cable

I find power cables to have a huge impact on the sound in my system. I have been finalizing some changes and have the system where I am very satisfied. The only gripe I have is that on certain recordings there can be some "brightness". At first I attributed it to my power conditioner (sound application RLS-1), but one thing I had never tried, was to replace the stock 20A cord that came with it. A friend had an extra 20A cord so I tried it. Lo and behold it is near perfect. Still crazy detail, but more musical. I could live with it the way it is, but I am curious about others' experience with power cords. What I am looking for is musical but still with significant detail. The Tara Cobalts are the definition of this, but I don't necessarily want to shell out that kind of $$$ again if I dont have to. Because it is a 20A cord, they are much harder to demo before buying.
Thanks,