It is mentioned i the specification list in the servicemanual for The BL3500 MK2, and I also have seen manuals for the wireless 1 with drawings where it has Two powerlinks sockets and one Ir socket, and in a user manual for Beolab 3500 it only has one DIN socket and is connected via ML. So guess there must have been at least two versions of the W1
Or maybe the BL3500 manual is not showing all the connectors on the W1
