Power conditioner for Sonic Frontiers amp

My Power 3 was clipping and I talked to Nick at SFI only to find out I made the "mistake" of plugging the amps to a power conditioner. SF products have good filters buildin, so they recommend plugging straight to the wall to gain the most current.

I have a pair of Sonic Fronters SPM 160 Monoblocks and I connected them to a PS Audio P-600 and a Tice power line conditioner and found that both conditioners limited the high end and somewhat compressed the music(the Tice more than the PS Audio). I now have the monoblocks plugged directly into a 20 amp dedicated line and the sound is excellent.