Most people have heard of a standard amplifier, but not something called a ‘pre-amplifier.’ While it is true that pre-amps are less common than normal amps, they are still just as useful, if not more so.
If you’re recording audio with a microphone for professional use, then you’ll need to use a pre-amp. While it is possible to record audio without one, your sound levels, and its clarity, will be significantly lower than if you had a pre-amp installed.
It’s comical that so many people, even techy people, don’t know about pre-amps when they’re everywhere, on every device that can record or play audio. Pre-amps can be found in USB microphones, mixers, and cheap audio interfaces. Some dedicated sound cards even have them built in.
If they’re so widespread, then they must exist for a reason; and that they do. The fundamental purpose of a preamplifier is to boost the sound that mics record in by default. The signal that is recorded is quite feeble, so the pre-amp boosts the signal, which it then sends to the actual amplifier for use.
The use of pre-amps is basic; different kinds of recording hardware, such as equalizers, keyboards, compressors, and analogue-to-digital converters expect a certain kind of signal, at a very particular frequency, called a line-level signal.
Line-level signals run at a higher frequency, which means that their signal is louder; so, when a signal does not meet those requirements needed by the relative hardware, the pre-amp kicks in to boost the signal and make it usable by the device.
However, not all is well and good. The main issue with using a pre-amp unprofessionally is this; when a preamp boosts the sound… well, it does just that. It increases the sound. All of it. Therefore, all of the unwanted hisses, hums, clicks and whatever background noise that is occurring at the time of the recording gets boosted as well, which means there is way too much background noise.
That’s why different EQ (equalizers) exist. They take certain Hz (Hertz) signals and boost them, while at the same time either turning down or leaving untouched individual sounds. That’s why audio output software has different EQ settings for listening to different types of music. Learn more about the purpose of Equalizers in this short video.
You’ll want to boost the clarity of the sound in an old 60’s rock song, not the bass. That’s why preamps exist; they handle all of that work behind the scenes, equalizing the sound levels to make the most consistent and best sounding output.
Most preamplifiers have two big knobs on them, representing the two main types of inputs. The first and more important input signal is called XLR. It accepts the cable that runs from your microphone to your computer. The latter is called TRS, and it receives and transmits frequencies from your electronic instrument to the DAW software on your device.
Those are the primary examples of what preamps do. They are the core of your recording (input) or playback (output) setup, and you can’t live without them if you create music with live instruments. It’s always good to have a high-quality one, too. Check out this article if you are looking for a bit more detail.