HT Bypass necessary?

generally the HT bypass functions as nothing more than a fixed level output operating at unity gain (bypasses the volume control). this is not strictly necessary, as any input will work in the same way if you're willing to run the volume up each time you select the input.

in your case, just run the main L / R outs from your HT processor into any input of the C15, run the volume up on the Mac pre, and match the levels using the HT processor.

just make sure you turn the volume back down on the C15 before switching to another input!

Right. It is best/easiest done with a preamp that has a stepped volume control so that resetting it to the appropriate level each time is reliable.

Kal

Thanks for the responses. So in connecting it in the manner described above, is the pre-pro going to have full volume control of the left and right fronts?

I should also mention that the pre has a processor loop, but i don't know if that is something that I will be able to use in this set-up.

So in connecting it in the manner described above, is the pre-pro going to have full volume control of the left and right fronts?

Yes, it will. I also would recommend when you do the level calibration, set the L & R trim output level to its maximum in the pre-pro, in this manner, you won't have to raise the volume in the preamp that much higher (safety leverage).