I found the direction of the USB-OTG cable to matter as well as the brand of cable for portable device -> E3 -> phones.   Not sure why, but the red USB (micro male to male A) cable is the only one that I've found to consistently work for a computer -> E3 -> headphones setup.   Bluetooth...

I just got the Soundblaster E3 amp, mostly to work with my Bose Quiet Comfort 3s. My previous bluetooth DAC (Audio Tecnika AT-PHA-05BT) wasn't powerful enough to drive them.   So far, very happy. I'm using it with my Nexus 7 tablet and HTC One M8.   A couple of notes:   * Many otherwise...