Sure just run the source "pass thru" the Denon to the tv and let the tv upconvert then let the receiver do the upconversion and compare the 2 - There should be the option on the Denon not to do the upconverting - not positive as I don't use the Denon

In my case I use the PS3 as the source 1.3a pass thru my Marantz to the Samsung 61" 1.3a which upconverts the SD to 1080p even better when BR is playing letting the PS3 decode DTS MA