i have a nord lead rack a motif es and mpc 2000 xl and this is how i have all my stuff connected. Connect the asr to the mpc midi (A)in and mid out. Connect the the proteus 2000 to the mpc midi (b) out. Youll have one more midi (b) in thats free up to connect to your computer when you need to track everything in using midi time code. Now where i shows your device and all the midi numbers 1a-16a a will allow you to you play the asr when you using the mpc as the main seq but asr as the sound source. If you change to device number midi 1b-16b, and still push the ars keys you notice that your now controlling the the asr by itself and the asr is not making any noise of its own, its just being used as a contoler.