I read those articles, but was very surprised to see in the description of the CAP3 that it was necessary to install battery power supplies to avoid audible electrical noise:
"Even though the clean battery power source of the Black Lightning was used to power the SOtM card that sends power to the USB receiver chip in the EMM Labs DAC2X I still heard harsh electrical noise through my speakers. Based on this test it appears that noise from the Seasonic PSU / motherboard combo is getting to the SOtM card via the PCIe slot's gold connectors"
I have to say I'm not impressed. Surely it shouldn't be necessary to use battery power supplies for a quiet system in a $1000 HTPC feeding an extremely expensive DAC. Does that mean all the less expensive CA projects suffer from "harsh electrical noise through [the] speakers"?