Shunyata Power cords Too Boomy and screechy?

High every one I have just bought a couple new power cords a year ago. And finally finished upgrading my intergraded amp to a high power tube power amp and tube preamp with phono. The power cords i bought are shunyata Zitron Vipers for my cd player and preamp and a Zitron Alpha Anolog for the power amp. Which I use on the preamp since it dose more good hooked up there. My speaker cables are Kimber 12tc with WBT gold bananas connectors. My interconnects are silver streaks with wbt ends as well.

I notice when i start playing female vocalist like Partrica Barber, Diana Krall and Ariana Grande, or most recordings with a piano, every thing starts to screech. And on the other hand some bass hevey or dynamic stuff like Michel Jackson, John mayer, Daft Punk, Sam Smith, Or Classical music it sounds like poping my woofers not even cranked up. Plus I don't have a quick system Cary SLP-98p CAD120s preamp and amp and totem forest speakers. And running kt-120 tubes which made the problems more noticeable.

I have tried trying out different interconnects that are copper and didn't make much of a difference. Then the main dealer I get most of my stuff from told me to try out the new Audioquset NRG-1000 power cords and three of them for my hole system. Which smoothed every thing out and all issues where gone!

The one thing is I'm stuck with now is what do I do with all of my shunyata cords. Which I bought from a different dealer that led me down the wrong path! Which I was lucky to go to an audio show. And got a 6ft NRG-1000 used in an audio demonstration, for around $900.
Has anyone had the same issue or noticed the same traits with shunyata?

I must say though that shunyata delivers the power to your system that it needs, but just harshens every thing up. Which the Audioqest gives you the power and without over powering anything and is more smooth detailed.