What are microphone preamps?

Let’s just put it simply, microphone preamps are devices which allow you to take the signals from what a microphone hears or picks up, so that they can be recorded into either your software program or recording device. That’s it! These amazing devices are not complicated at all. In fact, there is also nothing complicated about using one of them either. It should be noted that the majority of the time, professional audio equipment is actually very easy to use. It is my belief that sometimes engineers scare people who are not involved in making music away from it, by inventing a complexity that is really not there at all. Each of the devices that you use for podcasting, recording your voice on your smartphone or in playing a part in a public address announcement, all make use of a microphone preamp. Turning it up, so that you can hear yourself without clipping, distortion or picking up unwanted sounds or noises is the key to operating one effectively outside of a recording studio environment and in one, too. 

In the beginning, microphone preamps were completely intertwined with the history of audio itself. In fact, these devices date back to the invention of the microphone– not in the 1920s, but in the 1870s. The origin of the microphone, as we will explore later, is shrouded in mystery, with several imminent engineers and inventors laying claim to its creation, including: Emile Berliner, David Edward Hughes and Thomas Edison. It’s safe to say that each of these notable engineers and inventors created the device that we think of as a microphone at roughly the same time– around 1877 and that invention was inspired by another revolutionary innovation of the time– Alexander Graham Bell’s telephone in 1876. While the ability to hear microphones, use speakers and broadcast music existed by the 1920s, it was during this decade where a true push to create standalone microphone preamps to supplement the burgeoning radio broadcast and music recording industries began with such companies as RCA (in the United States), the BBC (in the United Kingdom) and Telefunken (in Germany) (among others) being early pioneers in this process. It was an important component of the early history of professional music recording. By the close of the Second World War, with the growth of vacuum tube technologies, and an interest in the recording of audio for music, film and broadcast, microphone preamps became one of the first components of the professional audio world to undergo rapid development. This development would see the microphone preamp transition from being stand-alone tube-based units to becoming the integral component to the development of the first consoles for music, film and broadcast. 

As solid state technologies developed by the mid-1960s, microphone preamps became smaller in size and found themselves as a part of the growing large-format console revolution. At first, as consoles were made by custom designers for recording studios (or in the case of Dick Swettingham at Olympic Recording Studios in London and the engineers at EMI, now Abbey Road, were made by the engineers as custom designs by the studio engineers themselves), microphone preamps for the very first time became the integral component of the channel strip– enabling multiple sound sources to be recorded at the same time. One company in the United States which pioneered this concept was Electrodyne which created the components for channel strips which could be installed in console frames or housings. Other early pioneers in this field included Spectra, Flickinger, Helios and Sound Techniques (among others)-- and by the late 1960s and early 1970s other companies which produced them, a few of which are dominant leaders in the field today, such as API, Neve and Trident emerged. As the popularity of these consoles and their modular preamp and equalization and dynamics (later) sections became staples of the music recording industry, engineers and producers who wished to carry their own units with them inspired the creation of stand-alone units and modules, some created by boutique manufacturers for the first time, while others simply racked-up the consoles modules which possessed their favorite sounds and carried them with them from studio to studio which became a hallmark of the industry by the mid-1980s that has continued into the present. 

In fact, most of the legendary preamps which you still find in modular form today including the (AMS-Neve) Neve 1073®, (API) API 312, and the (Trident Audio Developments) Trident A-Range came from this period, as did the fine boutique preamps that are available from such companies as John Hardy, Grace Designs, Manley Labs, George Massenburg Labs and Millennia Media Systems. Today, you can also find preamps that were inspired or are authentic versions of the preamps from the early days of the first large-scale consoles from such companies as Spectra1964 (Spectra), H2Audio (Helios), Skibbe Electronics (Flickinger) and Pete’s Place Audio (Electrodyne), as well. Microphone preamps come in a variety of forms: 500-series modules, rack-mount units and even as 80 series modules. They can be found on hardware interfaces, consoles and in rack-mount units. In addition, microphone preamps can be found in single-channel versions and in a few cases, you can find them in rack-mount units which feature up to 8 preamps. While preamps come in so many different versions, each of these units are incredibly easy to use. With such an array of amazing technologies available today in the world of professional audio, the question now becomes, “How do they work?” In the next section, we will discuss how to use a legendary microphone preamp for music recording– the Focusrite ISA microphone preamp.