line conditioner for amplifiers

i have noticed the beginning of the summer degradation in the quality of the ac. LIPA is doing it again.

so, i am considering a regenerator for my vtl deluxe 120s.

ps audio is one company manufacturing such a product, including models p 500 and p 1000.

i own a p300 which i use with a tube preamp, ultimate outlet and two tubed cd players.

i like the affect of the p 300 on treble frequencies.

is it possible the p 500 and/or p 1000 engender attenuation of the treble, the way the p 300 does ?