Met Aumkar and listened to the RR1 at CanJam today, two very pleasant experiences. The headphones sounded really nice out of both setups, one a KGSSHV (from birgir I think) and the other a little koss amp (the one that goes with their headphones, Massdrop version). I had a very pleasant listen with the smaller setup being run from an iBasso DAP (maybe DX150). I seriously would have bought that whole little setup on the spot for listening on vacation or the office. It had excellent bass and an extremely musical, engaging sound.
I'll probably buy a pair of these when they are for sale.
Aumkar is a great guy! Thanks for the overview and good luck.