Power cords will make a huge difference. You are likely just going to have to try a few and see what works for you. Also, consider dedicated lines with iso grounds if you don't already have them. I think that's the first step. Finally, consider, a conditioner first. I tried a bunch of cords, loved them all, but a Hydra did more for me than all the $1000 cords I have.
YMMV...
YMMV...