It is sadly true that the RX-Z1 is too old to use in a modern HT setup, not having HDMI and relying on optical/RF digital inputs to get multichannel processing. I think the problem (missing right main output) with these is actually in the digital multi-channel board somewhere because using the 6ch input (all discrete inputs) all channels on mine work fully and sound fantastic (also OK, as Brad mentioned, with discrete 2-channel stereo inputs without multi-channel processing). Moreover, these beautiful giant behemoths could be used as 6ch AMP MODE only, perhaps even with a multichannel preamp inputting the discrete 6ch inputs. It only takes one front-panel button to put it in 6ch direct input.

It would break my heart, too, to scrap mine (I have replaced it with a new flagship Yamaha). It is back in the original box in a closet now. ...including the unopened Pronto-style LCD remote. I hope I can find someone who would like to have it.