Core Material
The magnetic material used in the transformer’s core.
The core carries magnetic flux between the windings. Its material is distinct from the winding conductor, the core’s physical shape and the surrounding shield.
Core Material — Step-Up Transformer (SUT)
In a Phono Step-Up Transformer, the core forms part of the design that transfers a small cartridge signal to the secondary winding. Its behaviour matters alongside winding design, transformer size, loading and the intended signal range.
Descriptions may name nickel-iron alloys such as permalloy or mu-metal, amorphous material, nanocrystalline material or silicon steel. A named material belongs here only when it describes the core: a mu-metal shielding enclosure can surround a different core material.
Use the material to understand construction, rather than ranking transformers by the label alone. Terms such as toroidal or C-core describe shape, not material. Compare cartridge matching and relevant measured performance before drawing conclusions about how a complete transformer will work in your system.