Here is a conundrum. I make an MC phono stage that uses a SMPS as its power source and it performs very well, and squashes the belief that this couldn't work.
The DAVE dac is different in so many factors that upsampling and SMPS use is irrelevant, believe me. It is difficult for non techie people to appreciate the subtlety of the differences, but one of the overriding factors that gives the transparency and lack of digital nasties of DAVE and HUGO is the noise shaping software.
Think of it as part of the 'filtering' that is necessary when converting to analogue, traditional approaches with proprietary dac chips use FIR filtering, a well understood way of performing the filtering function in the digital domain. However with traditional approaches the residual noise, or 'noise floor' is modulated (affected in ultimate level) and this tends to mask the very low level signals that give the air and depth to the sonic image.
The different filter and noise shaping of DAVE gives immeasurable changes/modulation of the noise floor and results in spectacular transparency.
When I say the Chord technology is different I mean it is so advanced that no one else is using it, it is proprietary to Rob Watts and Chord.