"do the Mojo DACs require tube amplification to sound "natural?"
Not in my system, which is posted here on Audiogon. SMc Audio solid state preamp and two SMc Audio solid state monoblocks.
Another interesting article/post on that site is which provides one writer’s perspective on different categories of gear. If you look at the DAC list, you will find the Mystique EVO Pro 21 in the Holy Shit!! tier, but the X SE was apparently not listened to. It does provide a perspective on the Mojo Audio house sound, although IMO the X models move away from the "coloration" mentioned by the writer. However, OTOH, I believe what he calls "coloration" is a sonic attribute I find compelling on my EVO Pro Z, to the point where I seem to be unable to sell it an settle in with only the X SE NCZ.