Warm sounding power cord for for CD player to suppress digital glare on vocals.

Need more info about your setup. Is it a dedicated CDP or a CD  transport to a DAC? Preamp/amp, tubes or solid state, any digital cables?

I have found PCs such as Audience and Cardas provide a warm sonic signature, but I don't think changing a PC to prevent glare is the way to proceed. I don't know if a PC will even remove glare from a digital device.

Digital "glare" or harshness (if that's what you mean), comes from poor jitter control in the digital chain. Changing IC's may tame the offending frequencies, so can an EQ, but in the end, it's the source that needs to be addressed.

Well now that I know you have such a fine CD player, the glare you speak of is coming from the mastering of the CDs, and not player related. 
I can understand your search for a PC now, since I have noticed how they can have an effect on certain frequencies when used in a digital chain. It’s a lot of trial and error as you know.