We are trying to replace our stereo Sternberg UR-22 with the multi-channel LP-16 . The LP-16 connected via usb interface mode to my Macbook pro OS X El capitan. LP-16 recognized midi inputs from a Yamaha keyboard. The LP-16 will not recognize midi inputs from a Classic Midi Works CMK keyboard that perfectly works with the Steinberg UR-22 .The audio playback from my Mac source works fine in stereo mode. A disturbing side issue is that the LP-16 display is unresponsive to the top panel selection buttons.(mode,menu, etc.)