My thoughts:

1-If you are getting a buzz, get new wires.
2-Try something else that can connect to the Kn7000 Midi.(If you do not have something try to borrow)
3- Can you drive your module with something that you might have?

You have to isolate where the buzz is coming from. Even if you have to use an inexpensive Yamaha/Casio keyboard with Midi ports.

Let us know how you are doing.

John C.
Bill, what is the USB port used for. I thought it was used to connect the Kn7000 to a computer. I never use it.