Finally got it working with the phone. It was working with the PC but I finally got it working with my Phone after some aggravation. It seems the key to my problem was trying a different USB cable. I guess the OTG cable was fine... when plugged into my Motorola Droid Turbo it worked with USB drives. I'm using these OTG cables: https://www.amazon.com/gp/product/B00YOX4JU6/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1 But I just couldn't get it to recognize the Amp... In hindsight it seems the connection from the OTG to the AMP was fussy... I've tried a 3rd cable there and it finally worked! One of the cables I was trying to use I came with a drone for charging... i wonder if it can't do any data for some reason... Guess I"ll have to try the PC again and see which cable I used. Now I'm thinking of getting a 1 piece on the go cable to see if I can avoid this.