0.71mm wire coils should be used in applications requiring low current. The air core coils are unbeatable in terms of dynamics and the low distortion they introduce into the signal. For these reasons, for purists we have air core coils with wires up to 3 mm in diameter. In this way large inductances with relatively small internal resistance can be obtained. Vacuum impregnation, also applicable to air core coils, provides a greater degree of detail and an improvement of the sound scene in musical reproduction.