The 580 has definitely NO line-out.
I don't know about the 780.
I remember calling the guys from panasonic and during a
15 minute talk I heard about 4 different statements.
What a bunch of $#%@....
I guess it must have - how else could you justify the price difference between the 780 and the 580 (battery power? I dont think so)
I have a 570 and love it. Has a line-out, good oldfashioned volume pot ( this digital volume of the newer volumes IMHO really sucks, very hard to operate) and it's built like something that will last much longer than the fragile 580/780.
And it has 10 sec linear skip protection with no compression-> maximum sound quality (plus 40 sec if you wish)
I had my silver baby in my pocket the other day(with the linear protection), running up/down the stairs, working out, etc. It didn't skip even once.
If you must have the tiniest player, then get the 780, but for anything else go for the 570. It's a great player.
Bye
Redwoood