Roger Just been spending a few nights with my nose in Alec's fantastic book "Getting the most from your KN7000" if you read this in light of what you are trying to do,it appears that if you have the correct drivers you should be able to use just the USB. cable as it is possible to send MIDI and AUDIO both ways down the usb cable which would allow midi control from the KN down the usb and let the audio from your pad to return to the KN7000 as a line in and playing through the KN speakers. It looks as if you will need to load your pad with the drivers from the original CD rom for the KN or if this is not possible try getting generic drivers that will allow to set up midi and audio.

Best regards John.
P.S. perhaps technicsplayer may have an opinion?