The ODAC was designed to be used with USB power and the world class spec measurements were attained while using USB power.
There are lots of opinions on this and many will be glad to share them I am sure.
The ODAC was designed specifically with this in mind as one of the design points that is what you dont need to have .....to have DAC audio happiness...that is your DAC simply disappearing from the signal chain...
If you seach for the designers site you will find a list of things that are not needed according to him for audio excellence.
One of these is no need for eloborate and or high current power supplies...
I personally have tried this ODAC on several pc systems from IBM, Lenovo, Dell, Acer notebooks...with USB 2.0 and USB 3.0 ports.
I also tired it off of (2) USB powered buss's and several desktop systems, from Gateway, IBM, Lenovo, and (3) homebuilt pcs with boards from ASUS, EVGA,
I also measured the actual current draw with the ODAC in use....and staticly....the current draw doesnt come close to taxing most USB PC power sources....well under the 500 ma spec.
Also the USB cables I use have a ferrite bead for filtering of any HF crap that might get induced on the cable...and the ODAC also has a ferrite on the dac board as well...
The designer in his site has stated that USB power often degrades performance due to noise.
The design of the ODAC uses a split digital filter and analog power supplies each with their own filtering and regulation which can be seen by looking at the schematic that is now available on the web.
That said try and listen yourself and see if you can really hear any real world differences in using USB power vs a powered buss etc..
All the best
Edited by adydula - 11/2/12 at 7:05am