elevick,
you're talking about using a device as a "source selector", which your oppo can do. I'm talking about connecting two analog lines directly to the amplifier input. The Sunfire Cinema Grand has two RCA inputs and one XLR input FOR EACH CHANNEL. It allows you to use any of the 3 different inputs to supply a signal. However, you should never connect more than one analog source to any of the Sunfire input channels.