Re: Metal pickup covers change sound?
There is a difference, the sound will be warmer with nickel covers. More a jazz tone as opposed to a ruder, rock tone.
Try this...grab a couple nickels out of your pocket...let's say, 4. (20 cents) Play your bridge pup clean. Then throw your nickels on the pup between the polepieces, rigt down the middle of the two coils.
I bet you'll hear a difference.
What's happening is the nickels spread out the magnetic field. This results in the warmer rounder tone, as opposed to the concentrated field that causes the ruder, brighter one.