is this what you are looking for?
You can make it easely yourself. By both connectors at the nearest electronic-store.( You can use the 2 pin of your Rotel or buy a new one ) The 2 pin probably will be sealed to a wire. That's good. Cut the wire ( as short as you like) and connect the 3 pin on the other end. There will be no groundwire (or is it earthwire ?). I did it myself also and it costs about $ 5. Goodluck.
Or you can go here:
$9.95 Cnd. is about $8 U.S. at current exchange rates.
Excellent prices on a lot of stuff, including cyroed Hubbell 8300HI at around $17 U.S. (cheapest you'll see them anywhere else is around $32-$35).
I have no affiliation other than being a satisfied customer.