Llamas,

You may be correct about the zone 2 implementation of source/volume control received through the IR repeater jack.

I was looking at the Pioneer VSX-47TX manual last night and that's what it appears to do.

However, the problem with this for me and for other custom install uses is that all of my equipment is controlled by whole house IR. That is, in the HT, my equipment is in a closet behind the room, and even in the main listening room, I use IR repeating with infared blinker emitters. Obviously, I use the same emitters for the signals received downstairs (Zone 2). My Zone 2 is actually 4 pairs of speakers throught the lower level of my home (with independent volume control, but only one source for all four pairs of speakers). I have a total of 5 IR windows for receiving IR throughout the house.
So, I couldn't use the rear IR jack for Zone 2 control because my IR system for the HT and Zone 2 are integrated. With discrete codes, this isn't a problem.

If there are internal codes for which the Hex code info. can be determined, then I could put that into my Pronto. Otherwise, I'm out of luck.

-Cliff