Prioritization of Power Cords

Why can't you just try them in different places and where they sound the best? Well... That is where to leave them. What that DOES is make you TRUST YOUR OWN EARS.....                   
Instead of what others 'guess' at.
                                      

In general, you want your quietest power on your sources and then on the amplifiers with the most voltage gain.  As gain drops, it becomes less sensitive to power line noise, so power amps are less of a concern by comparison.  This is a general case, the fact is you never want power line noise to enter your system.   I agree with Elizabeth - listen and decide for yourself.  :-)

There are a number of PCs on the market specially designed or optimized for digital components, e.g. Triode Wire Labs, JPS Labs, and plenty others.  I wonder how they different from a PC for another low-powered component...