what is the difference between aluminum and brass bridges?

[cytodavid]

Does anyone know of the differences between aluminum and brass bridges? Are there differences in sound, sustain, or stability? Specifically, I'm looking purchasing a Hipshot A style direct replacement bridge for old fender basses. It comes in brass and aluminum and I don't know why I would choose one over the other.

[bigntasty]

I don't have personal experience with either, but I know brass is more dense than aluminum. I would guess that the brass bridge is heavier and offers more sustain, while aluminum is lighter.

Is the brass bridge nickel-plated? If they left the brass bridge natural, then maybe it's a color choice thing.

I don't know - just thinking out loud...