The DUO-CAPTURE EX (UA-22) compatibility information with iOS devices is as follows. For the compatible iPad models and required connection accessories for each iOS version, see the linked page.
iOS version
- iOS 5.1 - 8.4: https://www.roland.com/global/support/support_news/150716/#audioif
- iOS 10: https://www.roland.com/global/support/support_news/16100510510/
- iOS 11: https://www.roland.com/global/support/support_news/17092010511/
iOS 9 and iOS 12 or later are not compatible.