What kind of OTG cable has you tried and what kind are you ordering? Note that to get E5 USB Host mode working with UAPP, you need the microUSB-to-microUSB OTG cable. Sorry to inform you but A15+WMC-NWH10 only work on some USB DAC but not all. In the case of E5, it doesn't.
6/7/15 at 5:43am