This seems like a lot of watsed effort when you could use a Sony XA-39 (MK2) to do the same thing. The box takes the turn on leads from both head units to decide which signal to send to the amp. It also has its own turn on lead to turn on the amp whenever either unit is on. I believe that it if both head units are on, the box will pick one of them, I'm totally not sure how it does this, but i think it's the first unit on, so the only advantage to hacking the kernal here is not having to turn off the empeg (plus not having to buy the XA-39, plus equalizer on the cd, plus mythical cd visualizations in 1.1) Still probably not worth it, but it wouldn't hurt to try.