Pickup System
A pickup system consists of a stylus and a cartridge. These are the components of the turntable that convert
the sound waves etched on a record into an electrical signal. Two types of pickup systems are:
- Piezo-electric pickup systems
- Magnetic pickup systems
Piezo electric pickup systems
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Piezo electric pickup systems work by utilizing the natural electrical properties of certain types of crystals,
usually quartz. An electrical voltage is created when pressure is applied to the crystal. In a piezo electric pickup system,
the stylus is attached to the crystal, which protrudes from the end of the cartridge.
The pressure applied to the crystal comes from the motion of the stylus as it tracks the grooves
cut in the record. In other words, as the stylus moves along the grooves of the record, there is a slight wobbling, bumping movement which causes pressure
of different magnitudes to be
applied to the crystal. This pressure generates electrical voltage, which then, through the design of the cartridge, creates an electrical signal
to start flowing through the system. This signal then flows through some wires in the turntable and on to an amplifier.
Piezo electric pickup systems are usually fairly robust, and since the electrical voltage that is produced is proportional to the applied
pressure, these systems yield a good level of signal, and require only a small amount of amplification compared to magnetic pickup
systems.
Magnetic pickup systems
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The magnetic pickup system consists of either a moving magnet or moving coil mechanism. The stylus is connected to either
a magnet in the moving magnet
system or a set of coils in the moving coils system. In the case of the moving magnet system, the magnet is held close to a set of coils,
and as the stylus tracks the grooves of a record, it moves, making the magnet move near the set of coils. This then causes a
small electrical current to be induced in the coils. This signal flows through some wires in the turntable and on to an amplifier. A moving coil system
works in almost the same way, except that the coils that are attached to the stylus are near a stationary magnet, and the movement of the stylus as it
tracks the grooves of a record creates a fluctuating magnetic field. The stylus in a magnetic pickup system
is usually made out of diamond. This system is also very light, which decreased the need for tracking systems to be so robust.