- What sort of cable do I need?
- Can I make the cable as long as
I like?
- What else do I need?
- How do I join up the
ends?
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If you are joining two pieces of audio
or musical equipment together, or two audio PCB’s, or wiring controls to
an audio circuit, you need a special screened audio cable to keep the signal in
and any unwanted interference out.
The most common interference is
caused by the electrical field radiated by the 230 Volt AC mains supply. Every
mains cable, inside your walls or leading from the socket on the wall to
anything you plug in will transmit a 50Hz hum that will be picked up by any
lead connected to sensitive audio circuits in amplifiers.
Audio cables
are simply a wire or wires that are protected by an outer layer or shield of
woven or twisted wire or foil that picks up the unwanted hum before it reaches
your audio signal, and earths it harmlessly away.
As you will see if
you browse your Maplin catalogue, there are many different types of audio
screened cable and although all of them provide protection against hum, some
are more suited to particular jobs than others.
If you are wiring up
simple audio amplifiers to small loudspeakers, for an intercom or something
similar, hi-fi quality is probably not important. There are a number of
inexpensive, thin audio cables that are perfect for these applications,
particularly if the cable run is inside metal cased equipment or is only over
very short external runs. |
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