Hi all, I want to hook up a second optical input on my Denon DVR 1801. The first optical jack is assigned to DVD and when I try to assign the second to DVD as well, the first one switches to Off. How can I have two optical sources plugged in at the same time and switch between them on the receiver? I have had to manually unplug one optical cable and switch it out with the other one. That should not be necessary. Thanks in advance!