I was OK until my kids gave me a new TCL HD TV. OK. So far I have had a new DirecTv receiver/DVR installed. (No comment on that right now.) But I have some ignorance. Is my old Denon, which I have connected to the surround speakers, vcr, dvd player, and streaming player gizmo obsolete? Do I have to replace all of these things to get full benefit of the HD? Thanks.