Air coils, for physical reasons, are unbeatable in terms of precision on the restitution of the impulses, and are free of any distortion (contrary to ferrite coils). For this reason, Mundorf produces coils with a large wire diameter for purists. It is therefore possible to achieve better inductances while maintaining low internal impedance and zero distortion.

Baked varnished coil

When an electric current passes through a coil it causes the different windings to vibrate. The microphonic effect (conversion of a mechanical movement into electrical oscillations) adds these oscillations to the original musical signal. The varnished coils are made from a special wire. An extra layer of varnish on the outside of the wire is melted quickly by the passage of a strong electrical impulse. After this process, the coils are glued together and can therefore no longer emit vibrations.