I heard that these receptacles aren't that good and are waste of money, but I dunno. One guy I know of recommended to buy some cheap, well-made power strip, if it has any filters inside or something just take all out of it, he also soldered capacitor there, but I don't know why and he bought filter Schaffner FN2080-10-06 and connected it with the power strip. He told me to top that he would have to spend hundreds or thousands of $. I kinda took it with a grain of salt because this filter costs in USA 30-40$! But I know that this guy used to have these power conditioners from Gigawatt and Furutech, so I asked him: "You want to tell me that some crappy power strip and filter for 40$ beat something what costs 20x more". He said to me that it didn't but the difference wasn't night and day. He also used cables from Chris VenHaus at VHAudio claiming that it is best bang for the buck.
He wasn't really into headphones, but speakers guy, but one thing is funny that he had all this power related stuff, DIY speakers made by himself etc. and technically whole cable stuff came from BlueJeansCable. He didn't believe in this cable ******** and would rather improve things with power and acoustics.