Currently Being ModeratedApr 9, 2010 11:40 AM (in response to Cads666)RE: No sound from Vaio VGN-AR51J speakers/headphones
This is because the USB Audio Interfaces are external soundcards; they handle input and output via the same USB cable connection.
Most users purchase an external USB audio interface because they're typically an improvement over the built-in soundcards of the laptops.
Here's a document that covers this topic, and the photo in there illustrates the proper setup/behavior of our USB interface. Other manufacturer's USB audio interface follow the same behavior as well, so it's not a Line 6-thing per se.