I bought a Stealth HAC PC about a year ago. It isn't the best cord I have in my system, but it is better than my stock cords. I have not heard the amp you mentioned, but it is entirely possible that stock PC is better than the HAC. Almost everything in this hobby seems to be system dependent to some degree, especially cables. As Dekay advised give it some time to burn-in. You might give the Custom Power Cord Company (CPCC) Model 11 a try. In an audtion involving 9 or 10 PCs that included Stealth, JPS, MIT, HT, and others, I found it to be the best for analog and the Marigo Ultra Series II for digital; the Stealth came in third.