DACs with High Voltage Output

Al, this is great insight that I am not (yet) technically literate enough to have discerned on my own. I really appreciate your willingness to dig into this. I will contact Burson at the beginning of the week and see if I cannot get a fuller, or perhaps more accurate, picture of how their DAC outputs. 

As a follow up to your question, yes, the volume control on the Bel Canto is necessarily significantly below max when I run the attenuation on the Burson to full tilt.  

I will report back after talking with Burson.

I did talk with Burson. They say that the attenuation does indeed step the voltage output all the way from 0.5 to 10 vrms. That means the Bel Canto really needs at least 4 vrms to be happy.

Also, in response to david_ten: there is certainly a speaker component, as they are somewhat inefficient bookshelves (87 db - Rosso Fiorentino Fiesole). But I am in a small space and have heard them in other contexts with equivalent power (Matersound 845 based integrated) and there is plenty of headroom.