Power fluctuations; how to conquer ?

I live in a northern suburb outside of New York City. I am prone to brownouts and power failures. Even when the power is stable, I experience major fluctuations in performance. One day the system sound somewhat anemic, the next day it sounds spectacular. Highs are extended and the bass is rich, full and textured. I run everything through a Cullen Stage III modified PS Audio P500 except my Rowland Model 10 amp. I have found that when I put the amp in the P500 the soundstage is somewhat collapsed and the frequency range is slightly truncated.

Has anyone experienced this problem and found a reliable solution. I imagine the only solution is to find a conditioner for the P500 which does not limit the frequency extremes. However, I don't see how any conditioner that does not regenerate power can address the fluctuations in the quality of the power reaching the wall.

I would love to hear from fellow 'goners who have tackled this most frustrating problem.
Pure Power 2000 (purepoweraps.com) is a re-generator that produces a constant 120 volt and 60 Hz power. It does not limit current. With optional Power Pak battery back-up, music will not be interrupted even in case of complete power failure.
I use a Belkin Pure A/V Hybrid UPS 1500, it's a line conditioner and battery backup. I use it for my A/V gear and sources year round, on my on amp only in the summer when I frequently experience brownouts and occasional blackouts. As for killing dynamics, I haven't noticed a difference since my speakers are very efficient(95db) and my amp has plenty of reserve power(300wpc).

As for my other rig, I only listen late at night or early in the morning when power problems are usually not an issue since I'm using a 20wpc triode amp with 85db speakers.