Hi, I have a question for you about PS Audio Power Plants. Maybe I will briefly describe my situation that I am struggling with. I live in a multi-family block, a new apartment building with a Schindler elevator. Unfortunately, the elevator / motor of this elevator generates some type of interference, which is probably “let in” into the electrical network. While the elevator is moving, I hear such a steady screeching / high pitched noise in my ears. Oddly enough, I have two amplifiers and only one has such a problem. I would like to finally get rid of this problem, so I look at PS Audio DirectStream Power Plant 
Is this device able to regenerate the current in such a way that it prevents this type of “electrical dirt” from entering my audio system? The elevator engine is probably a powerful device, generating a nice “crap” to the electrical network …
Welcome @alito
I am a very satisfied customer, but do not have an elevator in the building. There are heat pumps / air conditioners and water heaters all around. The regenerator does a great job for me by regulating my wild voltage and eliminating any distortion in the incoming power.
Thanks @Serhan
My setup is a modest at best. I have Hegel H120 amp, Marantz AVR with Kef R in 5.1 config. Harbeth speakers are connected to Hegel. Sennheiser HD600s. Nothing very fancy. Hegel is silent thru Harbeths, but when I am using Sennheiser via Hegels headphone out high pitched noise from “elevator moving” is present. When using Marantz AVR the high pitched noise is always present when elevator is moving (on speakers and headphones).
You have a nice system, and do not underestimate its capabilities.
Are you in EU or a country where plugs can be inverted at the wall? If yes, you may test things by inverting the plugs.
Also, does the Marantz have a ground pole in the inlet? I have seen some products from Yamaha and Marantz skip it.
Currently, do you use a power conditioner / filter? What type or brand?
Welcome @alito. Serhan is correct a PS regenerator most models will show you how much THD is incoming. Is the apartment new to you or a new construction apartment building? Depending on the height of the building most elevators are hydraulic and any electricity will be on a dedicated circuit at a much higher voltage than what’s powering the apartment units. Sounds like something serious (not good) is happening if it’s creating noise while operating and should be addressed with maintenance. With that being said, if I were living in any apartment sharing electricity with multiple units I would definitely have a regenerator in my system regardless if I hear noise in the system or not. You will be amazed at what it will do for your system!