Hi Sam, You don't need a Midi -> USB adaptor with the SVM. Simply connect the MacBook to the rear USB socket with a standard A->B lead. The SVM appears as a midi device on the mac and can be mapped in the standard way. I personally have the upfaders on channels 2 & 3 mapped to the upfaders on ME and the crossfader linked with ME's crossfader. I then map the 'Fader Start' buttons as follows: Button 1 -> Upfader 1 Link, Button 2 -> Upfader 2 Link, Button 3 -> Link to Crossfader, Button 4 -> Link to Upfader. This then allows me to select how the software is controlling depending on the transition/mix I'm performing. The only other mapping I then assign is the Hi EQ on channel 4 (the channel I pipe ME's mixed video output through) to select the transition type. I use this set up every week so know it works ;)