Power cord replacement where first?

The digital source is what I'd suggest, the upgraded power cord will both improve the input to the CD player and also filters the digital nasties that are outputted into your power supply from the CD player. Two for one. None of the other components need both input and output improvements from the PC.

Like Eliz says, try it on both. Let us know your thoughts.

Thanks for the input I do not have the Kimber pc yet but, also looking at zu, audio art. Anything I can find under 100 dollars really. But I never thought of experimenting after I purchase it haha. Good thought . I also haven't changed speaker cable. I guess I should look into that as well. Basically I want to improve my system by adding to what I already have before considering changing existing which I really don't want to do

I still have monster xp speaker cables. Maybe I should replace them first?

I'm surprised nobody suggested upgrading your power to your wall outlets first. Dedicated 20amp lines for amps and source will make a much bigger improvement than power cords.