Hi,
I don't know if this will work for you as we've got a KN6000 but here goes. We use a standard lead with a headphone plug at one end (it goes into the socket on the 'board) with two jacks on the other which we plug into the left & right microphone sockets on our very old, but very trusted, Trio (!) tape-deck. Both channels record and we can even add Dolby NR. It's just a thought.
Lucy (Michie's sister)