I returned the power transformer to stock config and... no hum! I was experiencing the hum before in my other apartment building that I was living in half a year ago, but have since moved. I had originally dropped the bell end when I was living in my old place and had been running it like that for the 1/2 year, but no need any more!
I'm suspecting that there was something to do with the power in the previous building I was in as it was extremely old, each apartment had multiple dimmer switches, and each apartment was using many fluorescent ballasted lights.