Alnico (an acronym for aluminum, nickel, and cobalt) is a family of iron alloys. On the other hand, Ceramic magnets are made from ferrites (a mixed oxide of iron and one or more other metals). But, both Alnico and ferrites are used to make permanent magnets. Ceramic magnets generate a stronger magnetic field than Alnico, resulting in a slightly hotter-sounding pickup with more treble response. So, what's the difference tonewise: 1. Alnico magnets sound rounder, warmer, and smoother/sweeter. Also, they can be more dynamic, responding better to your playing style. But, they won't push the amp as hard as their ceramic counterparts. 2. Ceramic magnets have a higher output than Alnicos, resulting in a brighter and more transparent tone with some scooped mids. They also perform well under heavy distortion. The downside is that they can sound harsh, brittle, and thin.