BDM300 is a boadcast box with 3balanced stereo channels, has been specially designed for mobile use.  It includes: 

• Three USB soundcards equipped with the design stop buzz (galvanic isolation of the power supply, data + and Data -)
• The USB Hub internally for only one connection towards the PC.
• The interfaces start in keyboard emulator or USB Midi. 
• Its small dimensions allow to accommodate the case in a portable PC.
• The audio requires no specific driver.