Up until yesterday I was using only 1 old 4 way adaptor. I had no problems. Yesterday I had a tidy up of cables and used 2 new 4 way power adaptors in the conservatory. 1st adaptor powered the conservatory tv, dining room tv and sky+HD box. The 2nd adaptor powers the bluray, ps4, neet splitter (splits sky to conservatory and dining room) a belkin router used as a LAN hub. Tonight I noticed the dining room tv had started to buzz very slightly, so I have unplugged the dining room tv's power cable from the 1st new adaptor and swapped it into the 2nd new adaptor. The buzzing from the dining room to has now gone. So, what is the actual cause? Are the new adaptors rubbish? Or is it because both tv's were in the same adaptor? and they have a powered HDMI connection to both of them? Tomorrow I will mess around trying all possibilities. Main thing I'm asking is do I need better 4 way adaptors? And which ones would people recommend?