I found a couple of stores in Toronto selling the Pyramid 13.8VDC power supply although it is more expensive than the US - almost double the price. Shipping it from the US would be even more expensive because of shipping charges, duty etc. I am unsure if this PSU worth the money and how much it may better the original wall-wart. I read a lot of posts from US complaining that this crappy PSU runs hot and might affect the life of the dac. However, I bought my unit directly from the UK and get the 220V version which performs pretty well with an AC transformer. After a couple of hours, the wall-wart just feel lukewarm on the hand and the dac runs cool as well. I tried a couple of my bigger 120V wall-wart units (12VDC) on hand with 1A output but they sound a little muddy in the mid and bass with less details.
The dac has been run in for ~ 20 hours and it did not disappoint me - great details with smooth high, solid mid and tight bass. The vocal and musical instruments have better separation and the sound stage also improved. Before the dac, I output signal via coaxial from PC to my Harmon Kardon receiver. I must admit that I was very satisfied with the internal D/A converter of the receiver but v-dac did bring my system to another level.
The dac sounds a bit edgy on high frequency at first but the harshness gradually faded away as time went by. I also found that putting some tiny transparent rubber feet under the dac improve the tonal balance and tame the edginess. Now the whole spectrum sounds more musical and I hear much decay and air on the highs. The interconnect I use is a pair of Audioquest Lapis which is a very revealing cable. This trick really helps. I am very happy with the purchase and hope the sound continues to improve as it hits the 40 - 50 hour milestone.