incorporate 2 channel amp into multichannel system

I'm not familiar with how an HT Bypass works, but you can do what you want by getting a home theater receiver with preamp outputs. Then hook the preamp outs for the L&R mains on the receiver into a line input on the Creek. Hook your center and surround speakers to the receiver as you normally would. When you set up the receiver's multi-channel balance, set the volume control on the Creek to 12:00 (or some other easy-to-remember setting). When you want to watch a movie, just switch the Creek to whatever line input the receiver is hooked to, turn the volume on the Creek to 12:00, and you're set.

Yep, Edorr is correct. My bad for attempting a quickie response. The 12:00 setting has worked for me with my Yamaha receiver and the three different active preamps I have used in my 2-channel setup. The Creek is a much different animal. Not only does its preamp have a passive stage, but it also has three selectable gain stages. The actual volume control setting on the Creek will depend on several variables, including the output level from the receiver's preamp. A higher volume control setting on the Creek may be necessary to remain within the receiver's range.