I have been using the original iRigHD for years in my old iPad but now with a new iPad which has USB C, I cannot get the headphones output the sound of the effected guitar signal in either AmpliTube IOS or Garage Band IOS?
After trying everything, and searching all over the internet for an answer, it was just a case of maxing out the iPad volume. For some weird reason, this interface only kicks in monitoring at 9/10 and 10/10 on the iPad volume.