aqvox + primare = hum

I am running a fully balanced system through my tonearm cable to a aqvox stage, and then to primare a30.1. At times I get a loud hum through my speakers. At first I thought it could be DC pollution from a lamp that shares the outlet. I then separated them and still would get an occasional quick hum through the speakers. I realized then that the transformers were humming from the primare, which I think might be the cause. Has anyone had a similar experience with either the aqvox or primare, or just know what could be the problem?

Thanks in advance for any insight.