I just recently conducted the very same experiment. I unplugged my Hegel H590 integrate amp from my Audioquest Niagara 3000 and plugged it directly into the wall socket outlet. I wanted to find out for myself and I went back and forth just enough times to make a determination on what sounded better, overall. Plugging my amp into my power conditioner was the winner for overall better sound for my system. However, this was not always the case when I conducted this same comparison in the past. In most cases, direct into the wall sounded better, depending on what conditioner I was using at the time. I purchased the Audioquest Niagara 3000 conditioner specifically because of it's ability to not constrain an amps power and it appears to be extremely effective in not doing so.