Hi there, I have searched this forum about similar issues, but not really found an answer that might be my solution. Bought a hardly used Yamaha Cinema 5.1 Speaker system at an Estate sale, but it didnt have the factory receiver. I saw that it had a VGA type input to the powered Sub enclosure where the satelite speakers hook up to the 360 Watt amp.. I figured that I could modify the sub enclosure to hook my Onkyo receiver RCA output by grafting the cables together if I could find a schematic that showed what pins on the VGA would be where I needed to connect. Then read about the 12V input to signal "turn on/off" to Yamaha Amp. I have a friend who restores old radios/jukeboxes, and figure if he had some input/schematics might be able to figure it out. 2nd option, What about just bypassing the built in amp of the Yamaha, and just straight wiring the enclosure sub speaker to run off my Onkyo receiver. Its a 770watt THX/Dolby Pro Logic beast anyhow. Dont need the loudest/lowest delivery, just something to have good Home Theater sound when we watch DVD/BluRays and some stuff on High Def TV. Thanks