http://www.steim.org/steim/junxion_v3.html
I have more info here:
http://jordanbalagot.com/blog/2008/06/29/turn-wii-rock-band-instruments-into-real-instruments-with-junxion/
The rock band guitar works this way too.

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It may also be because i'm running the free 360 controller plugin from tattiebogle.net, which gives the 360 controllers their own slots (player 1, 2, 3, 4)
Try that plugin in if its not working out for you.... I haven't tried it without the plug-in so (Its awesome for n64 emulators!)
2. im pretty sure its 3/32 headphonses are 1/8
2) Nope, they're the same size. Like I said, I've tried it and it works with the game. It's a little finicky because if you have both the pedals connecting at the same time, they seem to cancel each other out.