I hooked up my Roland JV-50 using MIDI cords only, to my AudioboxUSB, then USB to the back of the computer (XP Home). I chose the Audiobox as my input and output device. I get no sound from headphones hooked to the Audiobox. When I try to record the keyboard, I get a message, after stopping the recording, that Audio data has been recorded, even though there is no audio hooked up- no audio cords from the keyboard, and no mic or instruments plugged into the Audiobox. The playback looks like regular midi data, even tho I can't hear it. Impossible to use it if I can't hear it.