How to run pre-amp with HT Processor

I am looking a couple of nice A/V Processors and I was wondering how I hook a good 2 channel pre amp to it? Should I just move the interconnects between the two when I switch or just use the Processor for everything.

Meridian 561
Lexicon MC-1
Krell HTS
Anthem AVM-20
run the front left and right speaker outputs from the processor to the 2-channel preamp's "video" or "aux" input. then connect your cd player, turntable, etc to the 2 channel pre and your HT stuff to the processor and then choose a spot for the 2 channel pre to stay, volume control wise, and match the processor levels for the center and surrounds around that. that way, whenever you watch movies or whatever, you just set the volume control on the 2 channel, turn it to "video" or "aux" or whatever, and it plays through. this is the only way you can have the maximum fidelity of your audio components and can use your processor through it without swapping out cables.

if this is confusing, look at my system. it's explained in more detail.
I tried using this method with my system and found that the system did not sound right. I am not sure if the front left and right pre outputs of my AV processor was rated to high or low for the inputs in my preamp. It actually sounded better when I used the tape loop and connected the DVD player through the tape loop. The only problem was that the DTS signal could not be processed this way and I can only use Dolby Digital signal. I must add though that the improvement sonically was such that the Dolby Digital signal match what the DTS sounded like before. The other option would be to purchase a preamp with the home theater bypass option.
The processors you listed should also be pretty good 2-channel preamps. But if you want both you need a 2-channel pre with a processor loop or unity-gain input to really do it right.