magnetic heads and multiple head assemblies, namely, magnetic recording heads, magnetic read/write transducers, magnetic diskheads, rigid heads, composite disk heads, thin-film disk heads, head/arm assemblies, head/gimbal assemblies, magnetic tape heads, digital heads, analog tape heads, ferrite tape heads, thin-film tape heads, tape head assemblies, magnetic stripe heads, optical disk heads, optical disk head assemblies; magnetic head test apparatus, magnetic head test apparatus, magnetic media test apparatus, and parts therefor