I have found the CAT Ultimate to be pretty much immune to the several power cords I have tried on it. I have tried the ESP Essence based on the recommendations of others and this thread. I was disappointed with the results as I didn't notice a great deal of difference. Then, I tried the Essence on my Pass Aleph 4 power amp. The bass was heavier, but not deeper. Overall, it was not an improvement. I went back to the stock power cord on the CAT and continue to use the Audioquest AC-12 on the Pass Amp, vowing to not waste any more money on aftermarket power cords.
