A preamp, whether in an audio interface or outboard, is often mentioned when talking about audio recording. But does preamp improve sound quality? Let’s find out.
Musicians, podcasters, and filmmakers are endlessly hunting for ways to improve their sound quality. And the chief factor that contributes to the final audio is the recording quality. Using quality microphones and pickups is the easiest way to have good recordings. However, neither of them would produce any sound without a preamp.
Does a preamp improve sound quality?
A preamp doesn’t improve the playback quality, but it might help you get cleaner recordings. It becomes true, especially when using a computer or a camera/recording device to record audio. However, if you already own professional recording equipment, you typically needn’t worry about preamps at all.
An audio interface is the most common gadget you probably already own that contains a preamp. Still, you might have also heard of outboard preamps, FetHeads, or Cloudlifters, especially if you are a guitarist or use a demanding mic like Shure SM7B.
This article will explore what these are, how they work, and why they are necessary. I will also explain when preamps might improve your audio recording quality. Let’s get started with the basics, shall we?
What Is A Preamp?
A preamp is a circuit that boosts the gain from a mic or instrument level to a line level. The audio level from your microphone’s diaphragm or a guitar pickup is way too soft to be of any use. Therefore, we use a preamp to increase the gain substantially so that an interface/recorder can pick the signal up.
Nitish at Sweetwater explains what preamps are with great detail in the following video. Have a look:
Types of Preamps
In general, there are two types of preamps: analog and digital. An analog preamp uses tube valves to boost the gain level, whereas a digital preamp uses electronic chips. Furthermore, you can also find hybrid preamp circuits with both analog and digital counterparts for each of their characters.
Analog preamps tend to add some distortion and noise in the audio, which can sound pleasant to some people. Also, if you push the gain, you will get saturation instead of clipped distortion. You’re probably familiar with the distorted guitar amp sound, which is a result of this character.
Conversely, digital preamps are almost completely clean and do not introduce any saturation. They create digital clipping when pushed, which most find unpleasant. Similarly, some preamps use digital preamps for general purposes and employ analog tubes for distortion when you want it. You’ll find such hybrid circuits mostly in guitar amps.
Where Will I Find A Preamp?
The most common place to find a preamp is an audio interface. Other than that, you’ll find it in a mixer and guitar amp. There are also dedicated outboard preamps or devices you use for additional gains, like the FetHead and Cloudlifter. You’ll typically use them when you have a particularly demanding mic.
Audio Interface vs. Dedicated Preamp
The primary difference is that an audio interface is dedicated for use with a computer, whereas a general preamp is traditional audio equipment. An audio interface features what’s known as an ‘analog-to-digital converter.’ It translates the analog signal from your mic/pickup into digital data that your computer understands.
However, a dedicated preamp doesn’t have that feature. Instead, it merely boosts the analog signal. You’ll need a mixer or an audio interface to convert the signal into digital data for your computer. Hence, the more common use for a preamp is to extend the number of inputs in an audio interface or a mixer.
Will A Preamp Improve My Sound Quality?
First, if you don’t yet own an audio interface, you can use an outboard preamp to input the mic signal into your computer’s line input to get much cleaner recordings. Second, a better preamp inside an audio interface makes a huge difference as well. So, when purchasing, acknowledge their preamp quality too.
I’m using the term “preamp” as a dedicated gadget like the Focusrite OctoPre first and as a component in recording equipment circuitry the second time. Another thing to consider is the tone. You might find subtle differences between two preamps, thanks to their circuitry, and not to mention that some employ onboard compressor, EQ, and other tone-shaping/dynamics processors.
However, if you already own a decent audio interface, an outboard preamp is unessential. Take a look at this article to know how to decide whether you own a good audio interface, and if not, how to buy one. You’ll also find a list of recommendations for every kind of budget and usage. But if you think you do need a preamp, have a look at these:
You’ll need to select a preamp based on the number of inputs you need and your intended use. For instance, if you want clean recordings from multiple mics, I would recommend a transformer-less preamp, whereas, for a characterful audio recording, I would suggest a tube/FET preamp. Let’s have a look at some of the best available in the market:
1. Neve 1073DPX
Iconic sound, extremely expensive
The Neve 1073DPX is a two-channel preamp with the exact specifications of the beloved 1970 channel amplifier 1073. It features a 3-band EQ and a high-pass filter per channel. Furthermore, you’ll find headphone monitoring, phantom power, and level meters. Also, you can purchase a Digital I/O module that lets you connect the preamp to your PC via FireWire.
Noise-free transparent sound, multi-inputs
If you own an audio interface featuring an ADAT input, you can use the Scarlett OctoPre to expand it with eight channels. The preamp uses the 3rd Gen Focusrite preamps with their proprietary Air mode to add unique top-end clarity. You’ll also get eight additional line-level inputs.
3. DBX 286S
DBX 286S comes with a single preamp, but it has plenty of features that add a lot of value. You’ll find a compressor, de-esser, low and high-frequency exciter, expander/gate, and phantom power. It’s a channel strip that can significantly improve voice recordings for musicians, performing artists, and streamers. Note that you will require an audio interface/sound card with line-level input to connect the preamp to your computer.
Marketing can often make equipment and gadgets seem way more necessary than they are in reality. But in most cases, bad audio recordings rarely appear because of your gear. Instead, you could be having issues with wires or even grounding. Here’s an article where I talk about recording noise and ways to remove it.
The most common case where you need a preamp is if you run out of them in your audio interface or mixer. For example, suppose you own a Focusrite Scarlett 4i4 with only two built-in preamps. Yet, you need to record five band members at once. You could either buy a new audio interface or get a preamp with four inputs and connect it to one of the line inputs in your audio interface.
K. M. Joshi is a multi-award-winning composer and sound designer, specializing in film, game, and TV audio. He enjoys making cinematic music, rock, blues, and electronica.