Akai MPC Forums - List of Working/Non Working Class Compliant USB Interfaces : MPC X, MPC One, MPC Live & MPC Key 61 - Page 29
Kenton MIDI USB Host Mk3 (for Class Compliant MIDI devices) - Control Voltage
Digi OS Upgrades: Class Compliant USB Audio & MIDI - YouTube
Amazon.com: USB MIDI Cable Converter Keyboard Music Editing Line, Easy to Turn PC into Music Studio, Record Songs, Connect Music Keyboard with The USB MIDI Cable : Musical Instruments
Elektron's free OS upgrade adds class-compliant USB audio to Digi machines