I found this super long thread, and unfortunately very hard to follow. 
The Definitive Guide to Trying to Connect Your OP-1 Via USB-MIDI - #202 by jonesy_op1
I simply want to use the OP-1 to connect to my Korg NTS-1 (I already have a Type-A midi adapter). As of now, what is the easiest device that does this? I want a simple USB midi in to DIN midi out box.