Well, it turns out I am wrong. What Peachtree said is that it was non-standard and would potentially be used for interaction with future products.
So I measured a small DC voltage spike signal that is sent in conjunction with the IR remote, so I have a signal I can potentially use to power on the new amp.
Now my problem is how to turn that signal into an on-off switch? I get a signal for every IR remote button, not just the power on/off switch (eg, volume control).