I do have the emm6, which is a usb mic.
(The way i understand it, is the umm6 is a better quality mic or it might be more versatile, or maybe newer, not sure about that information.)
But, the usb/emm6 still does have the ability to be used with the REW software.
So, i am using a wyred4sounds dac2 with this system. So I have an extra laptop computer and programmed my MS Windows based laptop withthe dac2 and the mic works with it. I am still not sure why it wont work with the macmini.
I got everything hooked up for testing, now. But I was called out of town and wont be able to start/complete any testing until i get back home.
When i get back, I'll see what I can do.
V....