Originally posted by Alexandru Mihaita:
I think that it wouldn't be too difficult to have the preamp modified to make one of its input sources "pass through".
I doubt that. It likely would involve some circuit board trace cutting among other things after any reverse engineering to figure out what to do in the first place. If there is relay swtiching, it might be impossible without major modification. Labor rates being what they are, I would bet that unless the preamp is extremely simple and laid out in an extremely obvious way, the cost to do such a mod would not be worth it.