Track Light Hum

Hi I have purchased several "Easy Lite" track light fixtures from Home Depot for lighting in my home recording studio. The model is F5MA-05. The first track that I set up works fine, however the others that I have set up in the same room have a buzz or hum that seems to be comeing from the transformer. Can anyone help me track down the cause of the hum? As it's a bit hard to record in the dark.

Thanks,
Scott