I've been experimenting with an LED panel and different dimmers, trying to find a dimmer that wouldn't make the LED buzz, or at least not buzz too loud. I found that this dimmer (it's a universal dimmer: it has a switch that turns it into a forward or reverse phase dimmer, depending on what the user wants), when set to 'reverse phase', it does not cause the LED to buzz at all -- I couldn't hear anything even in direct proximity to the LED driver. The only issue though is if the dimmer is turned off for a while (10 mins or more), then when I turn it back on, the LED doesn't light up right away, it takes ~3-5 seconds for it to come on -- no matter the brightness. But there is no delay if the dimmer's been off only for a short period of time. My question is why? It is very similar to a capacitor losing charge over time.
Incidentally, if the dimmer is set to 'forward phase' - there's no delay at all, but the LED driver buzzes far too loud, especially when the LED is dimmed about 50%.