Jazzgene - after experimenting with a few more power cords on my VS60, I agree with you that the VS60 is sensitive to the power cord. I guess the particular ones that I was swapping in and out back then just so happened to all be sonically similar.
component where PC does not make a difference
Has anyone ever had a component whose sound did not change significantly (or at all) with changes in power cords? I have found that different power cords don't really affect the sound of my amp (ARC VS60), but differences among those same power cords are revealed when hooking them to my DAC (ARC DAC7). Is that representative of tube amps in general or perhaps just this component? Would you expect that the differing "sonic traits" of various power cords would be better revealed on a DAC than a (tube) amp?