Hi, The external controller is a Yamaha MoxF, working fine as controller for all my other synths (although with regular midi cables). The Kenton Midi/USB host is brand new and 2 days old, I tried 3 different midi cables (expensive brands) from the MOXF8 midi out to the Kenton midi in, same result... the USB cable from the Kenton to the USB of the CT-S1 is a regular USB-B cable and that's not an expensive one. Could try to change that one and buy a more expensive.