I have several audio line out docks, one i use for portable amplification another to hook up to my home audio receiver. There just docks that plug into the dock and pass audio out to a cable. These all worked fine on the first gen Nano, but for some reason I can not get any audio to play through the dock. Is this something that is no longer supported on the 6th gen? Audio via the 3.5mm headphone jack works, but I would really like to by pass that and use the dock for output. I've also tried to restore back to default via itunes with no luck.