Voila! Good evening from middle Europe!
I will do my best. The Modulus 3 is holographic cool and has a more 3D sound stage. It can get quite spacious, airy and certainly has a rounder base than the Audio Research SP-11. In terms of transparency, the Modulus 3 is better than the SP-11 to my imagination, but the airy delicacy is not as present as with the SP-11 MK2 after hours of warm-up. After having heard I would easily go with the Modulus 3 due to lower maintenance costs and it is easier to put new tubes into the socket.
The MFA Magus is warm and full-bodied, does add some coloration to it that makes music sound extremely romantic somehow between Jadis and the SP-8 preamp. It never gets edgy is completely open at the top end as if it would never reach an end. The base is bloom and full like you hear on live concerts. While the Modulus 3 is more neutral and sweet the MFA Magus is extremely warm and too romantic.
If I would play with speakers and have a pair of Kappa 9's I would use the Modulus, with the Gamma or Beta I would certainly jump to the MFA Magus as the L-Emims favour more warmth than coolness.
I hope that helps.
Best,
Stefanovitch