A preamp is a device that is used to boost the signal received from any device that creates sound to bring it up to line level. It is necessary to understand how audio systems work to understand what a preamp is.
We see people speak into microphones or string the guitar and immediately hear the noise amplified many times over from huge speakers. We presume the mic is connected to the speaker and the voice is automatically amplified. That is not the case. The sound passes through a power amplifier which boosts the current and delivers the same to the speaker to increase its volume and reach. The preamp receives the signal directly from the mic and boosts the output of the mice and prepares the sound to be transmitted to the amplifier. Pre amp… get it? This device works before the sound is amplified.
Why is this necessary? Without going into the technical details, it is sufficient to understand that the sound output from the mic is very low in voltage. The same is boosted using the preamp to bring it up to line level. Line level is the level at which standard audio devices like synthesizers and CD players operate.
Think of a preamplifier as a growth supplement that boosts the sound so that it can go out and play with the big boys. Try connecting the mic directly to the amplifier and you will not get any noise. Why? The sound output of the mic is too weak and too low for the amplifier to even recognize. Enter… preamplifier to the rescue.
So the preamp makes the sound louder? By itself.. No. However, combine it with an amplifier and you can easily play with the current and voltage of the sound signal to make it louder.
That is all? No! Preamp can be used to alter the sound quality as well. It can be used to add texture or distortions to the sound. Distortion refers to alteration of the sound. It may be for the good or it may detract from the quality of the sound. Preamps add to the quality and make it more versatile.
The importance of the preamps can be understood from the fact that even the best mic will sound like an ordinary one if a poor quality device is used. On the other hand, a good quality preamplifier is enough to make even an ordinary mic sound very good.
The device can be a part of your mixer or can be attached externally as well. The choice is yours. An internal device ensures there is very little loss of sound quality due to external disturbances. On the other hand, an external device will be fitted between the mic and the mixer. This will give you more options to play with and enhance the modifications that can be made to the sound.
The mic and the preamplifier are analogous to the paint and brushes held in the hands of an artist. Just as the combination of brush and paint is enough for a good artist to make vivid images, a mic and preamp is enough for the musician to create versatile and multi textured sounds. Remove the preamp and you might as well ask a painter to paint without any brushes.
There was a time when amateur musicians and music bands had to virtually skip such devices due to excess costs. Today, you can use the web to get in touch with different sellers and suppliers and get the best quality devices at very affordable prices. You can have these sensitive devices delivered to your home and start using the same immediately.
