Plinius 9200 and power conditioning

I've been using a Hydra-4 with Copperhead power cables into my Plinius 9200. It reduced high end hash and added richness/fullness but greatly reduced soundstage depth and space around instruments compared to use of the Copperhead alone (i.e., no Hydra).

I'd like to keep the good attributes and eliminate the bad one obviously. I understand that Plinius does not recommend power conditioning for their amps.

Thanks for your recommendations!.......Terry