I'm looking into buying a Panasonic SA-HE200. My current idea is to use a simple stereo reciever to amp two more channels for the rear center. This would use the pre-outs from the Panasonic to send the signal. My question is, are the pre-outs line level (i.e. fixed volume) or are they variable level so that when I adjust the volume on the Panasonic, do the rear center volumes change? I ask this because the old stereo reciever doesn't have a remote and it would be a pain to walk over and change it every time. Thanks.