I just answered a similar question here.
http://forums.audioreview.com/general-audio/equalizers-20810.html
If you want to see if a receiver really has a tape monitor loop, first, locate the "tape monitor" switch on the front panel. The lack of this pretty much assures you do not have the necessary tape monitor loop.
With nothing connected to he outputs and inputs, press the "tape monitor" switch. The sound should disappear and reappear when you press it again.
Now, simply jumper the tape outputs and inputs with a plain old audio interconnect. Then, when you press the "tape monitor" button on the front panel the signal should still be there. Now, simply insert the equalizer and you'll be in business.,