The compatibility issue, I believe lays in the fact that the Berkeley doesn't have a USB input unless you buy a separate box.
Aurender only provides volume control on it's "A" series products which include a DAC and pre-amp.
The reason for this is "bit-stripping" which occurs when volume is controlled in the digital domain.
This is a very complicated and disputed subject but for the best sound quality consider adding a pre-amp to your system.
However in the meantime take a look at a DAC with a digital volume control until you get a pre-amp.
An excellent DAC that I use with my N20 is the Musetec 005, about $3k.