Ok I have this Sony STR-G3 receiver and I've had it for a little while, quite happy with it even though it isn't Dolby Digital. In any case it has this output on the back of it that's baffled me for the longest time as to what it's purpose is. This output is labeled as follows, it has a white border that at the top says Mixed and then inside the border right by the RCA connector is Audio Out. Would this be some kind of output to an equalizer or something else? I'd really like to know if this would be of some use to me.