"no power cord is going to set you free with that brightness problem".
You forgot to add, IMHO, no?
I'd have to disagree. If you've owned Shunyata King Cobra's and such, maybe they didn't work in your system. They sure smoothed out a bright preamp I had once. Of course it's gone now. I doubt your YBA is bright, though.
Yes, many find the Krell gear bright, but if he wants to keep it, there are ways of taming it.
Cardas interconnects and speaker cables are another option, IMHO.
Using cables and power cords as tone controls isn't the preffered method, but it is an option.
Cheers,
John