Well, things are never quite as easy as I'd like them to be. After taking a closer look at the L&R sigmals, it was clear that I couldn't just tap into the L&R preamp signal without doing a little massaging. I threw the 5500 and 6500 schematic at Claude, and eventually came up with this:
I'll take a second look at the electronics in the morning. For L&R, the 47 ohm, 100 ohm, and 1nF I have visually identified on the 6500 powerlink signal path, but I need to check the makeup of the circuitry around the transistor, and verify voltages. I also need to verify the suitability of using the TR2 collector for the speaker relay.
