I have the D90 SE>XLR Schitt Frey+ (passive buffer) >XLR VTV Pufifi>Revel F208's. Today I wanted to see how loud the system could play at unity gain so put on the hi rez version of Comfortably Numb and let's just say it was a quasi-religous experience. Is there a way to calculate how much power the Purifi was putting out at unity gain? I assume the DAC was outputting 4V on loud passages, as I found the 5V setting to overdrive the Freya+ and introduce distortion. It was so loud it was kinda scary and after the song was over my ears were ringing. The Freya+ was at full volume which I assume is unity gain. As an aside the Purifi amp case wasn't even warm. Crazy efficient.