USB on Mac (how to use digital to analog converter on mac with cocoa)

I have to play an audio file on digital to analog converter (Silverstone digital to analog converter Model number DB01S) on Mac ox x 10.6 with cocoa.

I used USBSimpleExample from apple but i am always getting this error

"dealWithInterface: unable to open interface. ret = e0开发者_JAVA技巧0002c5"

Any help would be appreciated!

Thanks

You use Core Audio, not Cocoa.

how to get Audio Device UID to pass into NSSound's setPlaybackDeviceIdentifier: