When you mention the power amplifier to someone who loves car stereos, you will get a long discussion about what it can do. However, the preamplifier is not only little understood by many, some don’t even know it exists. This is because the preamplifier is something that is vitally important, but hidden away in the car stereo system.

When you start pushing buttons on the front of the head unit, you are using the preamplifier part of the car radio system. This is because when you press something like the FM Button, the circuitry in the preamplifier needs to direct the signal that comes from the tuner to the power amplifier. This is also the case with any type of signal from CD to MP3s in the car stereo system.

In addition, items like the bass and treble, balance, fade, and more are all controlled by the preamplifier. In the higher-end car stereo systems, there can be as much as a seven-band equalizer that has been added into the head unit. This is an expanded tone control and that signal is fed through the preamplifier, then back into the equalizers with the signal altered per the adjustments. Then, the preamplifier will send the altered signal out to the power amplifier.

In most car stereo systems, the back of the head unit will have a group of wirings, called the wiring harness, and these carry a signal to the components of the system. In the better setups, the custom stereo systems, there will be a power amplifier at the rear of the car. Therefore, there will be a lead that goes directly into the preamplifier and exits to carry an inaudible signal to the power amplifier, where it is boosted and sent to the speakers.

The preamplifier is a very important part of the overall setup of the car stereo system. It is what directs the signals to the amplifier, and without that signal directed to the amplifier, there is no sound. Just because people don’t think about the preamplifier, it does not mean it is not important. If you can get a good preamplifier for your car stereo system, then you will have better quality sound going to your amplifier, especially if it is located at the rear of the car.

The preamplifier may be small, but it is mighty, and it should not be forgotten when you are putting together a custom car audio system. Doing so will only hurt the quality of your system.