Quote Originally Posted by cgrafx View Post
But then how do you decide when the channel is actually off or the source is just not playing anything?
Well, I would have thought that the converter itself would send a message to the software that said: "This circuit is now closed" or "This circuit is now open". If you plugged a mic in, it would complete the circuit and if you unplugged it - it would render it open. The converter could notice that and report it. Not high tech, particularly, but useful. I presume the converter is sending events - one type could indicate "plugged in".

I'm sure the reality is more complex than that. Maybe there's a standard that was itself the extension of an older standard some hardware still uses that wouldn't have required it and might crash if an event type was added. Or... you know: something. I've added bags on the side of enough tired old war horses to know that you rarely get what seems obvious to expect to work with.