I have an Zune80, and the connection at the bottom may or may not be a true line out. I have the dock for home audio, and when I connect the Zune, the volume control on it still works (like the headphone out jack when using an amp). With my Creative ZVM, which has a true line out, the volume control is rendered useless when using the line out plug via the home dock. I have no idea if that means anything, but my guess is the Zune80 has no true line out. However, it sounds just as good, if not better, connected to my home stereo and through a portable amp (using the headphone jack) as the ZVM. So I guess I don't really mind no line out.