I bought two Phillips bulbs at Home Depot. Both 60w equivalents rated at 800 lumens. One was labeled dimmable, the other was not. I first tried the non-dimmable. It worked fine at low and medium setting, but when I set it to high it was dimmer than the low setting. It also made a buzzing sound on all three settings. The dimmable bulb also worked fine at low and medium, but high resulted in rabid blinking like a strobe light. No buzzing though. I guess at this point it's easier to just replace the lamp.