I know that this is a can of worms. I have been burning in my C2 with a generic IEC power cord. Today I listened with my "less generic" cord that came on my Anthem Pre1. There was a noticeable improvement in bass definition, imaging and soundstage.
Are you using a "hi-end" PC, DIY, generic or what? I have built PC's in the past and currently use one on my CD D/A converter. Very nice improvement over the stock cord. I tried it on my Rogue PreAmp. To be perfectly honest, it did not make a big difference. Enough to leave it in, but not dramatic. The Rogue has an outboard power supply with an umbilical to the main unit.
What is everyone else using?
Cheers,
Geary