Sometimes a tape loop is not even helpful. I have, at least for another little while a Nad t773 until the 4600 gets here. If i stick a eq in the tape loop, the good news is that it does work for all non-digital sources. RAdio, tape, cd etc.
The bad news is that it does not use the sub this way, and NO surround modes work at all...none, notta, zip. Not even enhanced stereo yet alone plain old dolby pro logic. You can flick through all the modes, but they all sound the same. So Tape Loop is rendered useless.
In the case of the nad, it also has external loops in the back for each channel. Something i wish all amps had. So, you can take out the jumper for each channel, and put an eq straight into the receiver and you won't need external amps. This works for EVERYTHING and the surround modes, and digital 5.1/7.1 work fine because your eq's after the processing. BUT, there's always a BUT, at least with the EQ that I used, a Kenwood 7020 graphic eq, this method created more hiss then in the days of cassette's. Perhaps a Behringer would not create hiss, perhaps it would. If the Yamaha I have ordered does not impress me, I'll keep the nad, and go the behringer route but it's an expensive thing to order only to hook it up and find it hisses as well.
Bottom line is, why a $2000 amp this day and age does not have at least a 7 band eq in it is beyond me. It's simple software that is all. Now in my case i was lead to believe the NAD had this Amazing sound and I would NEVER EVER need a eq. Well, I was looking for an eq within 30 seconds of turning it on. weak Bass, too much mids, and not enough highs. Makes my Axiom m80's sound like F#@#$% Bose. Now with an eq, it sounds amazing. Luckily I'm dealing with a good store that their taking good care of my situation.