A friend of mine found this good article about XLR to RCA, or to 1/4 phono, and hums. It is a very good read IMO, and my friend is making me a new cable to the specs in the article to see if it eliminates the hum from going from the balanced XLRs to the RCAs on our Parasound amps. We have tried different outlets, cheater plugs an ART8, and none of them make any difference. We have tried 2 sts of XLR to RCA cables also with zero difference. I will post up the results of the new cables.