I have a Marantz sr6009 and an Integra dtr 30.4 and I want to run two pairs of speakers in sync: B&W CDM-7s and B&W 804 Nautilus series. I’m having trouble finding out how to do this as one stereo system (both receivers running a pair simultaneously). And it would also be helpful if there is a solution that doesn’t require a preamp just because I don’t own a current one and If it does I would also like to know if an old onkyo preamp would suffice. Appreciate the help!