I too was browsing all over the internet and yamaha's site and manuals about the IR-out part numbers, or setup.
Finally, I just bought an infrared LED emitter and a MONO jack from the local electronic parts store, and ... VOILA, it works.
You can even attach more than one LED to that same cable.
By the way, the total cost for the components (LED + jack) was less than 1 USD
Sorry I couldn't reply any sooner