That new block in iOS7 seems to have also blocked some of apple's own lightning to USB cables.  You get an error message "This cable is not certified and may not ..." and cable won't work for charging for example.   Annoying!!!!! 

Going to buy small dac and closed headphones. Any feedback from those that have tried either of these 2 combinations? microstreamer + momentum over ear OR vmoda m100 (I realize the headphones have very different signatures ...  flat vs fun) thanks for your help