What power cable for DAC?

I've had my PS Audio Digital Link III for a couple weeks now. The first week I ran it off the factory power cord and it sounded quite good. I figured it could benefit from a better pc so I got a Pangea AC-14 from Audio Advisor. Now I know this isn't the greatest pc on the market, but for the price I thought I couldn't go wrong. It has made my system a lot brighter and subdued the low notes significantly. Does anyone have any suggestions for a better pc for this dac?? If it makes any difference, my Arcam integrated amp is running off a PS Audio Prelude SC pc.