I've been pondering using the RME-ADI 2 DAC with an android phone, via USB-C connection and a something like this ...

I just bought one here : http://www.lemicrophone.fr/produit.php?ref=4260123363178&id_rubrique=272 Useful for French members, currently (Feb 2019) 50€ cheaper than Thomann. I would have waited, because I am right in the middle of moving house, but needs must .... The do not appear to deliver...