When I want to hear the sonic signature of a specific AC cable, I change all my AC cords back to stock & then install the "test" cable on my preamp. Bob Cohen at Fatwyre.com (Cable Co) advised my to try that approach long ago & it seems to work very well. So after the preamp is 'tuned' appropriately then go the the source component (one box CD player, or DAC, or the phono stage for an analog rig) & tune that component with the AC cord of your liking. Tune the power amp last, because if you do that piece first instead then all of your tuning work on the front end will also be affected
