@mike30 what I was getting at is that you dont have enough data. Ive owned this amp on multiple occasions, it shouldnt have noise. What power treatment were they using? Was the amp plugged into the wall? What about the circuit? What kind of power cable? Is it a dedicated or shared circuit? Shared power strip with switched mode devices?
you really should utilize the dealer channel. You think it will cost you more but it will save you money in the long run.