I have just had some 230V GU10 LED downlights installed in my living room (by a professional) to replace a traditional pendant fitting.
At the same time, we added a (mechanical) dimmer, however it gives off a very audible buzz from the switch and the light fittings on anything but full.
The light fittings and bulbs are all rated as dimmable, and the dimmer is specifically designed for mains-voltage LEDs, I'm told that this is an unfortunate by-product of using a mechanical dimmer; every dimmer switch I've ever owned has given off an audible hum, but not to this extent and never from the light fittings as well as the switch. There is a second adjustment fine-tune pot on the back of the dimmer, however this is for adjusting in case of flicker, and does nothing but "shift" the hum to different brightnesses.
So, my question is twofold: is the above valid? Are there alternatives, like some kind of switch with 3 positions (e.g. off/low/hi) that may not give off the same hum?