I have a DNA-1 Deluxe with the SMc Audio Revision A; in 2014 I had SMc upgrade AC inlet to Furutech and replace internal wiring with Shunyata Cohergenic (Steve’s suggestion). Great amp became even better.
If it works for you, I also recommend the Lightspeed Attenuator from George Stantscheff. A unique product that offers outstanding clarity that pairs well with the McCormack allowing the amp to be heard.