After one of my toilets is flushed, and it fills the bowl back up, I sometimes get a loud thrumming/humming noise.
It is the flusher stacky thingy making the noise. I turned down the volume of water flow into the toilet and it stopped making it. When it is doing it, the water tube from the wall to the toilet is literally vibrating in my hand.
Is this the water supply vibrating at a frequency that my flushy-stacky-thingy is exposing as noise, or something else?
Per Tester101's comment, I should note it only makes the noise, when the tank is full, and not running water through the pipes.