I am trying to backup .aif files from a synthesizer on my Moto X. The synthesizer (OP-1) is OTG. The USB adapter is OTG. And supposedly the Moto X is OTG capable. I've tried a number of file transfer/ file manager/ media player apps with no luck. The synth doesn't show up on the phone. Do I need to install different drivers? Am I using the wrong apps? Is it because .aif is more mac? I'm sorry - I'm a tech novice. I know there must be a way!