Lee,

I install mostly Marantz surround sound receivers and I have not found any codes for controlling the tuner from the 2nd or 3rd zone. It's a bit of a pain.

I do have a xantech unit that plugs into the green MULTI RC input in the back of a marantz receiver but I have not tried it out yet so I don't know what kind of functionality it will provide. I have a strong feeling it will act more or less like an IR repeater. I'll let you know if I'm wrong about that.

Sean.