@Phaedrux it is the stock bed heater. @Veti's suggestion of doing the PID tuning worked. I'm not sure what the buzzing noise was, but it didn't repeat and the PID tuning went smoothly for but the bed and hot end.
I've now got everything up and running. I just finished setting up a custom printer in Cura and am running a test print now. I'm not expecting miracles on this first pass but I'm keeping my fingers crossed for it to complete so I can figure out where I need to start with tuning parameters.
Thanks,
David