Audio Preamplifier / Line Driver

Description

The primary concept of designing this line driver / preamplifier circuit is to be able to perceive music from a remote location by running an elongated cable.

To define a preamplifier, or preamp, it is a device normally used together with the sound equipment to be of assistance in improving the overall quality of sound by detecting and strengthening weak signals for subsequent and more powerful amplification stages. In order to achieve this, the preamplifier increases the power and sound of the device, to assist the main amplifier while receiving electronic signal. The preamplifier releases low level signal to line level to prepare the amplifier to accept electronic signal.

For the reason that a preamplifier is intended long cables and due to its low impedance, a remote sound or music can be obtained without having to purchase high priced concealed cables. Using an ordinary loudspeaker and cable together with alarm cable connection is achievable because of the extremely low output impedance approximately 16 ohms at 1 KHz frequency. The proper position that needs to be set on a preamplifier is typically near the sound or music source. Then the signal would travel along the preamp cables having a peripheral amplifier at the end where a loudspeaker is connected. This is to boost the signal since the circuit will include a gain to somewhat less than one.

Application

A preamplifier may be integrated into a sound system in a diverse approach by placing inside the shelter of the power amplifier that is in contact with or it may have its own container. In hi-fi entertainment system, the preamplifier is placed closely while maintaining distance with power amplifier.

Source:www.zen22142.zen.co.uk/Circuits/Audio/linedrv.htm