Does your system sound better at night? If so then I would first suggest dedicated circuits (if possible) first. I just had dedicated circuits added and all I can say is WOW. A couple of weeks later I added a Topaz isolation transformer. I honestly can say the transformer made little to no difference. I do not mean to say the transformer isn't doing its job but the dedicated circuit made the biggest difference. According to the Topaz specs it does reduce normal mode noise (hot to neutral) by -65db and common mode noise (neutral to ground) by -146db. So an isolation transformer is another option. It is strictly for isolation and does not limit current (except for what it is rated at). It has no filters.
Power Conditioning: How Do You Know You Need It?
Like many, I have been considering whether to purchase a power conditioner (e.g., PS Audio Power Plant Premier), that sort of solution for electric noise. Accepting the premise that cleaning the AC will improve the sound, how do I know whether I actually have a problem that needs to be solved? That is, how do I determine whether the AC coming out of my wall outlets is actually dirty, before dropping two large on a device that I might not actually need? Living in Chicago, I would *assume* my electricity is as dirty as it gets, but how would I *prove* that before investing in a power conditioner? And I suspect the real issue may be noise occurring *inside* my home, like my WiFi router, energy-saving compact fluorescent lights, the 6-foot tall Tesla coil I keep running 24/7 "just in case" next to the hamster cage, etc.