I've been building and upgrading my hifi over the better part of the past decade with used gear. I honestly feel that I'm almost at the "done" stage. The sound is better than I could have ever dreamed of.
This looks like a modern day take on an old school '70s stereo. Very cool indeed. Please don't up grade this system. Keep it intact in another room if you get the itch. (BTW isn't the rx4109 a receiver because it's listed as an amplifier, but that may be just a quirk w/ A'gons program until you edit your system.)