My first 950 had some hiss ,but not really bad,I decided to change for the red dot,and to my surprise,the hiss was terribly loud.A few days ago, I decided to play with the pre. My first 950 calibration was to put the volume in -10, then with the spl, the test tone showed 74-75 at the fronts. at 0db, and I calibrated the other speakers based on the main at 0db ,75db(spl) and vol of -10.
With the red dot, I did the same, but the spl showed around 67db,I made no changes on the 950, and the result was a high hiss.Then I decided to increase the gain on the 950 to reach, With the vol in -10,75db on spl,my fronts went from 0 to +3, and I calibrated the others to match the fronts. final result NO HISS.