Something doesn’t add up. The input sensitivity of the Premier 11 is 950mV, which is high, but not as high as some CJ amps. Some are on the order of 500-600mV. I can see where 25 db of gain and 100 db speakers would pose a problem. But the Sys should have been much better in this regard.
For comparison, my system.
Amp input sensitivity = 1.5v
Speaker sensitivity = 104 db
Preamp = 0 db of gain (Hattor Audio passive).
I am able to run comfortably at 80% of the volume control of the Hattor most of the time. I can reach 90% when listening at very loud levels. Ideally, you’d want to be at the upper end of most preamps which is the least attenuation. In your situation with the Schiit passive pre I would think you should be at 80% or more of max volume.
I’m not saying you don’t know what you are talking about, but it seems strange that a passive pre doesn’t gel in your system. On paper it’s a perfect match.
PS
Another thought. What is the output of your source? Standard 2v digital output or something higher?