LP cartridges produce a low voltage, 3 to 4 mv, a CD player around a volt. Also the LP are made to the RIAA curve, this has to be equalized. You need a high gain phono input with RIAA equalization.
To use it with a modern receiver like your Denon, you need a phono preamp.
http://www.needledoctor.com/Online-Store/Phono-Preamps
People post on this again and again by the way. You could have found the answer in numerous posts about this topic in these forums. It would be nice if there was a vinyl and vintage forum. I think that would make it easier.