(from another post): I have CLS IIZ's and I've tried a variety of high-quality (some pretty expensive) PC's in different locations in my system -- including Audio Metallurgy, Aural thrills, XLO, Purist Venustas, and some custom jobbies.
After using progressively better and more expensive PC's in different locations, I have come to a few conclusions regarding the speakers, the CD transport, and the power amp:
Bigger is better! Namely, 9 and 10 AWG PC's always gave better sonic performance. Shielding is essential for PC's used with anything digital (in my case just the DAC and CD transport) but not necessary for amps. I don't know about the "antenna effect" of stats mentioned in an earlier post. My CLS's are powered with 10 AWG Aural Thrills silver PC's. They aren't shielded but have a ferrite bead on each end. In addition, there is a 8 x 12 inch sheet of Stillpoints ers cloth on the top of each electronics chassis. Going from the stock ML PC, to the XLO (12 AWG) to the Aural Thrills (10 AWG), the performance just got better and better.