The Schiit Mjolnir 1 definitely did feed and XLR-out with SE-in, so the Magnius should as well.
I heard back from Schiit, and I quote:
It should totally work to do single ended into the Magnius and out from Magnius balanced into the Sundara's.
So, what I can conclude is that the Magnius (and the Topping A50s for that matter) are not dual differential amplifiers. It appears that they are using an op amp to create a differential signal and boost the input nominal voltage to 4 volts. I guess this would be why the Magnius is well reviewed in its balanced mode, but is reviewed poorly in the single ended mode; it's design focus and performance is in the balanced output pathway.
Another takeaway here is that one should be careful purchasing an amplifier with balanced outputs if you don't intend to run balanced. You may be short changing yourself without even knowing it.
Now to scratch my head and add another $50-60 for a balanced headphone cable if I decide to go that way.
I do like the idea of having a lot more power for dynamic passages. When I worked in the consumer audio world, I was able to build and listen to $50-$100k systems, and the one thing that was a huge challenge is capturing the dynamics of the music.
The other day I was walking through the city with my dog. As I was passing a bunch of apartment buildings, I heard what I thought was an incredible sound system. I thought it was someone in an apartment with their windows open, but the more I listened the more I was thinking how can it sound so good? Yes, it was loud, but there was no compression. I finally gave in to my curiosity and decided I had to find out where this sound system lives.
As I walked back to the alley I was greeted by a church choir practicing outside behind the church. That is why it sounded that good. It was, by definition, an incredible sound system! That is the unachievable goal I ascribe to. Never reached, but I keep on looking... at a reasonable price!
