I haven't used an iPad with this adapter, but I have used both an iPhone SE and an iPod touch with the adapter. The two devices I've used most with them are the Chord Mojo and the Schiit Eitr (a USB->SPDIF converter). I don't have any measuring equipment but I can say they sound fairly transparent, meaning I can't tell the difference between using that adapter and say, connecting a computer directly to one of these devices. One thing I've noticed is that occasionally I get skipping or momentary dropouts with iOS devices using this or the USB2 adapter on any DAC I've used with it. It seems sometimes related to if I'm using another app at the same time as listening (like browsing on Safari), but I can't pin it down exactly. For the iPod, I typically fresh reboot it and don't use any other apps except the music player (either the builtin, Spotify, or Onkyo HF player) for best results.