So this is where we tap the PC Board of the input modules. It is just past the main 10K Master fader and just prior to the pan matrix, the PCB pad is marked O1 on the PCB. From here the orange wire that is seen going off left of the image goes to a DB9 connector that will end up on the front plane of each input module. I chose to do it this way so as not to have to modify the already heavily populated backplane. This could be done mind you but it takes some PCB surgery two spots for each module and that's 64 operations that must be done right in close quarters. NO THANKS!