I've had 7.1 for so long that I've forgotten where the down mix conversion is done. Would this be done at the player or the receiver. After skimming my receiver manual, I saw nothing and I can't locate my player manual after the move. Thanks.

I have my Panasonic DMP 60 set to bitstream to my Denon, the receiver should realize I only have 5.1 and do the conversion without me having to tell it to, right?

Yes.

The receiver will downmix as long as you've told it that there are no speakers connected to an output.

Thanks, that's what I thought