Hi! I wrote to the list about this socket as I wasn't quite sure what it was, the manuals for Altec products certainly aren't designed to be recognised by OCR software <smile>.
Thanks to those who wrote to me on the topic, the socket is a line-in as many of you suspected it may be, what got me confused was that the system has 2 line-in sockets, obviously the one on the back and another one on the desktop controller and it was the latter I had been using. To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org