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VACUUM IMPREGNATION & BAKED VARNISH <strong>COIL</strong>S<br />
In non-impregnated coils, vibration occurs as a result of the current flowing through the<br />
coil. The microphonic effect, i.e. the conversion of mechanical into electric oscillations,<br />
adds these oscillations back to the original signal as additional information. In this way,<br />
details of the original signal are overlaid and rendered unrecognisable. The music loses<br />
spatial quality and transparency. This process is prevented by vacuum impregnation.<br />
In vacuum impregnation, the coil is first impregnated with a special lacquer under<br />
vacuum. Because of the vacuum, this lacquer flows right into the innermost windings.<br />
The lacquer is subsequently dried in an oven at 130 øC. Thus the whole coil is baked into<br />
a very solid unit. The individual windings are prevented from vibrating and the original<br />
signal remains uncorrupted.<br />
Vacuum impregnation preserves musical details which give the music natural liveliness<br />
and an excellent spatial quality. It is thus an important component for a really audiophile<br />
reproduction of music.<br />
The price for vacuum impregnation is € 8.40 per coil.<br />
The windings of baked varnish coils are made using a special wire. After the coil has<br />
been wound it is heated up causing an additional layer of varnish on the wire to melt,<br />
bonding the individual windings firmly together. The effect is similar to that achieved with<br />
vacuum impregnation, but this process is cheaper for small coils. Baked varnish coils<br />
are available with winding diameters from 0.71mm – 1.40mm. All series are identified<br />
with a “b” prefix.<br />
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