Nav, on that Marantz as in the Spec 1 also, there is a provision in the pre to do speaker switching. The amp out is brought back to the speaker selection board and handled from there.
Ken - ignore my comment in post #18. Diagraming it out would be a drawing or explanation of how you hooked it up but that's a moot point now that Lee educated me on the speaker select section of the Marantz.