I think there's a huge potential here that may not have been previously mentioned. This should enable powering the pupDAC using USB on the go, from a mobile device, right, without completely draining the phone immediately, and without the likely crappy power coming off the phone(/wallwart that some OTG adapters can handle)?
Yes, indeed. You just have to observe the minimum input voltage requirements.
It would run quite nicely off 12 volt vehicle power. For DC, anywhere between
9 vdc and 12vdc would work great. Just don't exceed the working voltage of the
input cap which is 16vdc in the BOM.
Hmm ... maybe I should start stocking some car adapters!?