It's a pretty common arrangement, SUT into MM phono for MC cart, and many (Art Dudley most notably) argue that it's far superior to the active gain provided by an MC-capable phono stage. That has certainly proven true for me with the Black Cube SE II - which is a very adjustable MC-capable pre. Going straight into the Cube set with MC settings, the sound is very good, utterly quiet. But through the SUT into the Cube with MM settings, the sound is much more alive, bass is punchier, a lot more air and detail. It's not a subtle improvement. Maybe this will not be the case with another phono pre like the Manley, I don't know. But the evidence for this approach with my current phono pre is overwhelming, in my system at least.