Power conditioners don't restrict all noise coming from the outlets in the house. My Shunyata Denali allows noise through to my speakers when I click on my vpi record cleaner. Clearly audible. So your Niagara won't stop everything on the line.
Short?
I have a McIntosh integrated hybrid tube amp / VPI table / Revel speakers. When the AC comes on or off in the room i hear a loud pop. I used to think it was a scratch on the album but now I realize its some sort of elelctrical issue. I thought it might be a table grounding ussue but now it also happens occaisionally now when I'm not playing an album. So does the amp need to be grounded? And to what? Thanks.