Contact DCCA he can custom build you a cord that can do what you need. I believe that there is something wrong somewhere in your system that you will need to address. I believe that a power cord should not change the character of the sound just make it better. I have used DCCA power cords in the past to tune my system but now I have a different philosophy. I now put more emphasis on the equipment then the cabling. I found my self spending less on the equipment and more on the cabling in total spending more than if I would bought the right equipment in the first place. I do not by cheap cabling but good quality/value. I learned this from legendary people in the industry that when I went to their homes and I was shocked at how good their systems sounded and what they were not using for cabling. Just a side not for cheap you should buy several of the big spike kits from Parts Express and put some your equipment on the spikes. It's a cheap tweak and it tightens up the bass and it opens up the top end.
Neutral to Lean Power Cord for tube preamp
I recently added a deHavilland UltraVerve preamp to my system. It is quite powerful and dynamic, but has a little too much bass emphasis through my Von Schweikert speakers, driven by a McCormack DNA-1. All cables are silver, using a VooDoo power cord now on the preamp. Everything plugs into a PS Audio Quintet on a dedicated line. Looking for a very neutral, or slightly lean more detailed power cord, price range is up to $400 used. I am still tube rolling, so bass may get tamed a bit more yet.