Hey Anthony, You don't need any sound cards since the 900 is certified. I dont have a 900 (i have a 2000) but I would assume it would be just like my Denon DN-X1700 mixer that is certified. first turn all your channel selectors to USB. Then go to Traktor and into the setup wizard. follow the steps for your djm 900 that should be under the pioneer selection. Then you should be good to go. You can go into your settings in Traktor to make sure that the djm 900 is selected as your sound card. (which the setup wizard will do) Then go to time code and check that you see the "ring" spinning. "VERY IMPORTANT". make sure the midi button on your mixer is "on" before you open Traktor. Good Luck.