Its all in my sig, but.....
Schoeps MK4 > nBox + > R090HR set to 20 and every switch off
20!? You know what signal that takes for 0dBFS?
And you are using a 'pre'?
And no, what level is the 0dbfs? That was my initial question
The nbox+ is the pre-amp
Pre is way too much here.
At 20 on the HR you need around 18.5 dBu for 0dBFS.
So you are amplifiying and then attenuating way too much. You probably don't need a pre anyway.
On the 9 it is around 8 dBu with level at 9.
Please correct me if my numbers are wrong.