Conrad Boom 80 MkII Notice D'emploi page 24

Beware that the electrical conductivity is limited due to the increased use of gluing technology
in car manufacture or the lacquering of metal parts, not each metal component is suited to
function as an earthing point.
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Distribute the power supply in a star-shaped way, i.e. the connections of the negative leads start from one
and the same point for all components of the car hi-fi system. This way of distributing the power supply
avoids earth loops.
Connect the positive leads in the same way.
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