Weird connection results


I have an oppo 205 connected via analog XLR to a marantz 8802a to a lexicon RX-7 to Revel studio 2 and Fathom 212v2.  I sometimes run in pure audio mode or apply audyssey and it sounds fine 
I wanted to play around a bit so I turned the oppo volume down to zero from fixed 100, then Unplugged  the XLR from the marantz to lexicon and connected the xlr from the oppo right into the lexicon. I turned up the volume and it sounded terrible and the left channel was significantly lower than the right. Give I used the same cables, output from the oppo and input to the lexicon with no change to the speakers I’m at a loss at this outcome.  Any thoughts?  
esthlos13