Updated June 3, 2023

Welcome to our comprehensive guide to mic preamps, where we will provide valuable insights into the technology and explore some top-rated options.

You’re a home studio musician looking to elevate the quality of your recordings and are looking for the best mic preamp to add vibe and colour to your tracks?

Or perhaps you’re wondering why you even need a microphone preamp in the first place? Hell, what is a preamp? If any of these questions apply to you then you’ve come to the right place.

Microphone preamps play a crucial role in the signal chain of recording equipment, amplifying mic signals to line level. While audio interfaces often come with built-in mic preamps, dedicated hardware preamps offer improved sound quality, specific character, more gain, and sometimes lower noise.

In this guide, we’ll delve into the different types of mic preamps, explore some of models for every budget, and discuss whether investing in a dedicated outboard preamp is a good choice for your home studio.

In short, a mic preamp is a box of circuits and components that work to serve two main functions: adjust the impedance of the microphone’s output to match the requirements of your recording equipment, and amplify the weak audio signal from the microphone to a usable level.

This allows the signal to be properly processed and avoids unwanted noise interference. Microphone signals are typically very low-level, and preamps apply appropriate voltage gain to make the signal usable, minimizing the impact of noise introduced during subsequent processing.

Furthermore, the components in a given mic preamp will either produce a signature sound so remarkable that engineers are willing to pay thousands of dollars for them, or they are completely transparent but wildly powerful.

For the novice, buying recording gear can get overwhelming. Factoring in all of the influences that microphones, preamps, A/D converters, signal processing, studio monitors and room acoustics will have on a recording is huge undertaking.

Anything along the electronic signal path will affect the audio in some sort of way. When it comes to preamps, you have two choices: a) Add coloration or b) Be transparent.

There is no right or wrong choice here and the best answer is simply what sounds best to your ears. Considering that you don’t have access to preamps before purchasing to make this distinction, do a deep dive into the model used to on your favourite recordings and look for a variety of models that offer similar sonic characteristics. Many brands are developing more affordable units that are modelled after higher end ones

Tube preamps offer colour, body, vibe, and oftentimes a vintage character reminiscent of older recordings. The degree in which you implement these characteristics can be precisely dialled-in to flavour. This can be great if you’re recording a vocalist with a thin voice, and would like to give it some foundation and warmth.

To understand why adjectives such as “fat” and ‘body” are used to describe the sonic character of a tube preamp, it’s good to understand what’s going on under the hood. Tubes produce a mellow distortion as the signal level increases. This distortion takes place at exactly the same note for several octaves above the fundamental note being played. The octave reinforces the fundamental tone, similar to the effect known as doubling. This effect “beefens-up” the sound, hence the multitude of savoury adjectives engineers use to describe it.

Tube preamps are also said to “glue” sounds together better. This is a result of their circuit design which applies a natural compression to the top of the wave forms as gain is gradually applied. This compression is musical and pleasing, and when applied to several instruments, grouped instrument auxiliary busses, or a master buss, it is described to “glue” things together naturally.

A solid state preamp aims to reproduce the true original audio as transparently as possible without modifying the intrinsic tone or timbre whatsoever.

Instead of using tubes, solid state preamps achieve gain through transistors which operate more consistently as gain increases. This allows them to be brought up to maximum levels with very very minimal distortion. 

These are great for processing the audio signal to taste before it reaches your DAW. A channel strip is a standalone unit that most commonly includes a preamp, EQ, and a compressor/limiter. These are the fundamental processing applications for any audio recording, and if used well on a channel strip, can save you plenty of time down the road in post production. The goal of a channel strip is to replicate a single channel from a large, traditional mixing console but in a smaller rackmount enclosure.

A channel strip is a fantastic tool if you are very comfortable working with the signal processing applications they feature. If you are not comfortable dialling in the parameters of a compressor to suit a given performance, you may only ruin the audio before it reaches your DAW. This means you can’t go back and fix it later—you would have to record a whole new take. Therefore, channel strips are typically ideal for seasoned engineers. If you’re a novice, we recommend getting comfortable with plugins first.

As mentioned, most audio interfaces in the market today come with built-in mic preamps. These preamps are designed to provide clean and transparent amplification, even in affordable and compact interfaces. While more expensive interfaces tend to have better preamp quality, the built-in options are sufficient for recording decent signals.

If you’re using a budget audio interface and are considering investing in an outboard preamp, your money may be better spent on upgrading to a more premium audio interface. We’d recommend something from Universal Audio or RME as their interfaces are known to come with very high-quality preamps.

Outboard mic preamps, commonly found in professional recording studios, offer a significant upgrade in sound quality and tonal options. They are standalone devices that bypass the preamps in audio interfaces or mixing desks. While these can get outrageously expensive for home studio owners, there are plenty of options available in all price ranges.

It’s hard to discuss the sonic character of each through text, so we’d recommend figuring out which sonic characteristics you’re after and find models that do just that. From there, dig around for some before and after examples either from a company website or YouTube. 

 

Preamp plugins are software-based emulations of hardware preamps, designed to replicate the sonic characteristics of popular analog preamp models. They are convenient and cost-effective, as they can be used directly within digital audio workstations (DAWs) without the need for additional hardware. 

Most top plugin manufacturers are developing preamp plugins with many users claiming they hear no difference between the two. Without weighing in on the debate, these products will only get better and with time and it doesn’t look like their outboard equivalents will be getting cheaper any time soon. 

Preamps are available in single-, dual-, or multi-channel versions and you want to make a choice based on what you can afford and the type of recording you plan to be doing in the future. 

Any microphone preamplifier will have one microphone input and one line-level output. Some have a hi-Z Direct Input (DI) on them for recording guitar, bass, and other electric instruments directly. They may feature both an XLR and 1/4″ TRS output for more connectivity options to match your set up.

Some models of microphone preamps offer built-in A/D converter that enables your to send a digital signal from the preamp directly into your audio interface. This would produce a lower noise floor than an analog connection and would open up your interfaces analog input for a different application