no sound card on midibox.
but Midi via USB to Control Tractor.
what you probally need for FADERS (if you need more then 8 Pots and Faders):
http://www.ucapps.de/mbhp_ainser8.html
or
http://www.ucapps.de/mbhp_ainser64.html
and as Brain and Midinterface to Traktor:
http://www.ucapps.de/mbhp_core_stm32f4.html
The Firmware you might use is:
http://www.ucapps.de/midibox_ng.html
it is not out of the box "Traktor" its out of the Box "Midicontroller" - so you have to configure it.
and not necessery, but usefull a Dislplay:
http://www.ucapps.de/mbhp_lcd.html
you also will need Mios Studio to upload new Code or to Configure your Midicontroller (if you dont use LCD thats the way to configure):
http://www.ucapps.de/mios_studio.html
but first after you finished your CORE-STM32F4, you have to upload the bootloader: http://www.ucapps.de/mios_bootstrap.html