According to an article over at healthybuildingscience.com each light bulb type radiates a different magnetic field. To make matters even worse, different brands matter as well. To make a lot of testing into an easy to remember article do the following:
Where applicable run old fashioned light bulbs made by GE. Believe it or not the old incandescent bulb may burn up a lot of electricity but they also don't pollute your lines with dirty electricity. In addition they have the lowest amount of electromagnetic interference.
Tired of spending a fortune on your electric bill? Then go to Home Depot and the made in the USA brand of LED bulbs by Cree. They produce only marginally more EMI than an incandescent.
Lastly if you have CFL bulbs or florescent bulbs of any kind on the same circuit or even the same room as your audio system, replace them immediately. While they last years and burn little electricity they are like little noise generators which pollute your electricity going to your system.
