Another unconventional power cord test?

As I continue to experiment by recording noise in my system by placing a sensitive mic about an inch away from my right channel tweeter, I've stumbled upon an interesting finding: my computer, a simple windows laptop, when plugged into my PS Audio Duet filter, adds a tremendous amount of noise - relative of course. So I plugged the computer into a different circuit and wouldn't you know it the noise is gone. Very interesting, and I never would have guessed or heard this without this listening method that I've been toying with.

I've just bought a shunyata viper high current cable - $265 - and did some testing with it plugged from the amp to the wall, then into the Duet. I then did the same test with one of my PS Audio Lab cables. Again, my findings are interesting: hands down the ps audio lab cable is much quieter. And in all configurations there's less noise with the amp plugged directly into the wall.

I'm still breaking the shunyata in so I'll repeat the test soon. Anybody have any thoughts on this approach or the findings? Will the break in of the viper cord really make that much of a difference or am I sending that cord back to Musicdirect?