SC is the single coil pickup found in the Series I and Series II basses and guitars. These only work with the Series I and II electronics.
The AXY came next. This was made in the same potting shell as the SC pickups, even though the magnetic core of these humcancelling pickups is half the size of the SC magnetic core.
The MXY was made to fit the coil from an AXY in the smallest possible casing. Since many of our bass designs were smaller and smaller, the big AXY pickups didn't look right, and they didn't have to be that big. Imagine an Essence with AXY pickups!
The FatBoy pickup we use on the Excel bass (and on custom orders) uses the SC magnetic core wound as a self humcancelling pickup.
A regular AXY and MXY will have no sonic difference. The wider aperture FatBoy AXY will have a bigger, broader sound due to the fact that the magnetic core is wider and looks at a bigger portion of the string. The SC pickups sound, well, the best, what can I say? They are our top of the line, and they sound like it.
