power cord replacement...source or amp first?

Anytime you can improve the source, everything downstream benefits. However, in this hobby, the rule of thumb isn't always perfect...Try both cords on both and see what synergistically sounds better....

While they can help on any component, our experience is that they are most effective on transports/DACs/Phono Stages - then Pre-amps - then amps.

Depending on the quality of the power supplies etc in your equipment, you do have to try for yourself. The above are "norms."

Yours in Music,

cool..thanks for replying folks...

Agreed with above posts. I would add that power-hungry equipment (i.e. with high power consumption) can often seem to benefit more; and also check whether your own equipment includes any internal RF or other mains filtering devices. I f it doesn't, that's where to aim your aftermarket leads. Change one thing at a time. In my experience of using Kimber and Nordost mains leads, I would observe that CD players and power amps benefited the most.