Question about Onkyo receivers and equalizers

I have been trying to hook up a 10 band graphic equalizer to my Onkyo HT-R500 reveiver with no luck. I have followed the instructions flowlessly and searched for help on the net and still can not resolve this issue. I have set the receiver to MD and followed the proper tape loop hook up but can only get the receiver to work with analog connections straight to my player. Am I mistaken to think that the equalizer should be able to function with an optical or coaxial connection. Almost fogot to mention that the equalizer is an Audio Source EQ 100. Thanks for the help.

[Clint DeBoer]

Are you looping the pre-amp outputs through it and using the tape loop?

Explain what is feeding the unit and what it is sending signal to...

I am using the tape inputs and outputs on the receiver and using the tape loop.  I can get the equalizer to equalize an analog signal not not an optical or coaxial signal.  Is it possible to equalize an optical or coaxial signal?  I am sorry, I am very new to the idea of equalizers.  Thanks