Hi, I am very interested in the information you have gained on the unmarked 3.5mm jack. Sorry I do not own a wii however I do own a GHWT drum kit for the xbox and have been wondering what that jack was for. In the xbox manual it states it is an external trigger but I have found no other information about it untill your post. I measured the voltage and found it was ~3V with no resistance. Cby thrustersb - Hardware