Ozzy and Tweakers :
I added another copper sleeve on the preamp cord, with an additional increase in dynamics.
A good idea would be to gage the coupler size to your specific power cord end(s) so they are not a sloppy fit.
I might go with 1-1/4" straight across, instead of the reducer from
1-1/2" (provides a closer fit yet)
This is a cheap, awesome tweak, takes seconds to install, is reversible and refundable.
The beauty is, increased musicality with no discernable downsides (in my system)
I'm going to try the other end of each power cord going into the Hydra next.