What is a power amplifier ?

                                 What is a power amplifier ?

A power amplifier is a machine that amplifies a small signal to drive a speaker to emit sound. In the field of home audio, it can usually be divided into a preamplifier, a power amplifier and an integrated amplifier.

After receiving the signal amplified by the previous stage, the power amplifier of the latter stage amplifies it again, and finally drives the speaker with sufficient output power. Usually the power amplifier does not have a volume control.

The pre-amplifier (usually referred to as the pre-amplifier) is specially designed to amplify the weak signal transmitted from the signal source (such as CD player, radio, vinyl record player, etc.) first, and prepare to amplify it again for the latter stage, so it is called "pre-amplifier". "class. In addition to amplifying weak signals in advance, the preamp also has the function of selecting and switching different signal sources and adjusting the volume. Some preamps even provide more complex functions, such as high, medium, and low frequency adjustments.

The integrated power amplifier is equivalent to combining the pre-amplifier and the post-amplifier into one, accommodating the two in one chassis, with the preliminary amplification of the pre-amplifier, various control and adjustment functions, and the ability of the post-amplifier to drive the speaker.

What sequence should be paid attention to when connecting the signal source with the power amplifier and speakers? What should be paid attention to when the power amplifier is connected to the speaker cable?

When doing any wiring, please remember to turn off the power amplifier first, so as to avoid the tragedy of burning the speaker. In terms of starting and shutting down, when starting up, remember the principle of turning on the front end first, and then turn on the back end in sequence, that is to say, first turn on the signal source, then turn on the front amplifier, and then turn on the rear amplifier.

When shutting down, it is the opposite, first turn off the rear stage, then turn off the front stage, and finally turn off the signal source. The reason this has to be done is to avoid burning out the loudspeaker due to the powerful pulses generated at the moment of power-on or power-off. When connecting the speaker cable, be sure to turn off the power amplifier first to avoid a short circuit caused by accidentally touching the red and black ends of the speaker cable to each other. Once the speaker line is short-circuited, it is likely to burn out the power output stage of the power amplifier.