Do Microphone Preamplifiers Improve Sound/Audio Quality?

If you're a musician, filmmaker, or podcaster, I'm positive you've searched endlessly to achieve optimal sound quality to improve the consumer's experience of your projects. In many conversations regarding this topic, microphone preamplifiers are at the heart of the discussion.

Do microphone preamplifiers improve sound/audio quality? A mic preamp will affect audio quality as it applies gain and improves the signal level. Any “improvement” will depend on the mic in question and the clarity or colour of the preamp. Preamps tend to affect the tone/quality of low-output dynamic or ribbon mics more than high-output condenser mics.

When purchasing a microphone with an internal preamplifier or an external type, you will notice an improvement in audio quality. Although this quality upgrade can differ from the microphone you have, it'll be much more pristine.

In this article, we'll discuss the benefits of using a microphone preamplifier and some helpful knowledge about the subject.

Related My New Microphone articles:
• The Ultimate Microphone Preamplifier Buyer’s Guide
• Top 13 Best Microphone Preamplifier Brands In The World
• Do Microphones Amplify Sound And/Or Audio?

---

The Benefits Of Using A Microphone Preamplifier

Microphone preamplifiers are necessary to bring mic level signals (-60 dBV and -20 dBV) up to line level (nominal level of +4dBu or 1.78 dBV) for use with professional equipment. Microphones output mic level signals and need preamps to be used with mixing consoles, recording devices or digital audio workstations.

In other words, microphones output very weak signals (many electric instruments do, too). To mix and record these signals with other line level signals (the standard for mixing and recording), the mic needs gain, conveniently supplied by the preamp.

For more information on decibels, check out my article What Are Decibels? The Ultimate dB Guide For Audio & Sound

So, it's not that a microphone preamplifier necessarily improves the quality of the microphone signal itself. Rather, it supplies gain to ensure that the quality of the mic signal is maintained without severe degradation.

A mic preamp will affect the tonal characteristics to some degree, especially at high gain levels. This tonal variety between different preamps suits some microphones (and sound sources or music genres) better than others.

On the topic of gain staging, note that line level signals (from mixing boards, audio interfaces, playback devices, etc.) will require power amplifiers to boost their signal levels to speaker level to drive loudspeakers properly.

To learn more about microphones and their need for preamps, check out my article What Is A Microphone Preamplifier & Why Does A Mic Need One?

Now that we understand that preamplifiers can improve audio quality, let's discuss more in-depth the sheer benefits using a high-quality preamp can provide.

Better Overall Performance

A microphone preamplifier aims to convert a low output into a louder, clearer, accurate line level. Therefore, it radically improves the mic's overall performance immensely. With this attachment, instruments, voices, or other related sounds can be exerted in a much more premium way to the audience, undoubtedly enhancing their experience.

Transparency

Another reason microphone preamplifiers were invented was to improve transparency, and they do just that. A good preamp will continuously sound immaculate without any signs of “hissing”, usually showcased in budget models.

Of course, some preamps will be more transparent than others. Sometimes, the cleanest gain possible is required for a microphone and sound source. Other times, a more coloured preamp (with non-flat frequency response, impedance response or harmonic distortion profile) may better suit the application.

Related article: Complete Guide To Microphone Preamplifier Specifications

Versatility

Additionally, they have a wide range of configurations suitable for almost all situations. For live sound engineers, a microphone preamplifier is an essential component of their touring recording rig. Similarly, studio engineers rely on quality microphone preamps to record with their microphones.

Consistency

Over time, you'll become more familiar with preamplifiers, such as the sounds and characteristics of any given device. By experimenting with microphones and preamplifiers, you'll start to discover their ideal applications or settings, enhancing the audio quality even further.

So, without a microphone preamplifier, you'll struggle to convert a low-output sound into a much cleaner and louder line level. For the most optimal results, you'll want to invest in a preamp circuit suitable for the sounds you're recording.

---

What Are The Different Types Of Preamplifier Circuits?

As mentioned, there are different types of preamplifiers you can purchase for your setup, each offering its unique benefits. To ensure you have the best-suited preamp for your system, you'll want to become familiar with the below information.

1. Tube Preamplifier

A tube preamplifier uses vacuum-like tubes to boost the input signal. The preamp is well-known to add deep bass, warm presence, and airy highs in midrange frequencies. Tube coloration can range from either clean, creamy, gritty, or distorted, depending on your overall goals.

The way they operate is the following: as the signal increases, the tubes within the device start producing mild harmonic distortion. These even harmonics begin to stack onto the fundamentals, resulting in more depth, body, and weight. In the words of sound engineers, they commonly refer to this as “beefy” or “fat” sounds.

Alternatively, it could also provide sound through its compression characteristics. If you're given the opportunity to look at waveforms presented by tube preamps, it'll usually showcase a curve at the peak of the wave as it becomes subtly compressed or flattened when more gain is applied. Including this, tubes also clean and smooth out transients, making high-frequency content more pleasurable.

The Chandler REDD.47 is a great example of a single-channel tube mic preamp.

2. Solid-State Preamplifier

Unlike the above, a solid-state preamplifier uses transistors or op-amps to enhance a signal. The audio signals outputted from a solid-state preamp come directly from the design and components. Depending on which design you opt-in for, they might have different op-amps and transistors that offer an array of distortion.

When implementing this preamplifier into your system, you can expect a consistent, natural, and clean sound. Usually, this is much richer than what's presented with a tube preamp, but it depends on the device's quality. Also, it's known that solid-state preamplifiers stay trouble-free for many years, making them an ideal investment.

The Neve 1073LB 500 is a fantastic example of a solid-state microphone preamplifier. Its top-notch Class-A circuitry is based on the original Neve 80 series console preamp, packed into the superb 500 Series modular format.

For a more holistic discussion on solid-state and tube amps, including preamp, check out my article, Solid-State Vs. Tube Amplifiers (Pre, Power & Guitar Amps).

3. Hybrid Preamplifier

The name itself, “hybrid,” is a massive giveaway of what this preamplifier is used for, as it'll combine the best of both worlds. In most instances, the tube components are employed during the output stage and the input stage, the solid-state elements.

Having a preamplifier that applies both components allows you to add an abundance of colour to your audio. With hybrid preamps, you can get fat, clean, and natural sounds without continuously swapping between tubes and solid-state preamps. Undoubtedly, by utilizing this style of preamp, you'll provide the audience with a satisfying experience.

The PreSonus BlueTube DP V2 is an example of a hybrid microphone preamplifier. Each of its two channels has mixable XMAX solid-state and 12AX7-based tube preamp circuits.

---

Which Microphone Preamplifier Is Best For My Recording?

The above states the three types of preamplifiers offered within the market, but which is best suited to your recording? To better understand this, here are some scenarios you'll want to consider.

Classical Music

When recording or amplifying classical music, the most superior choice will unquestionably be a solid-state preamp, as it'll allow for a more transparent, pure, and clean sound.

Thin Sound Sources

Whether it's a sax or singer, it could be flattened using a tube or a colourful solid-state preamp.

Acoustic Instruments

Many acoustic instruments (such as the acoustic guitar) will benefit significantly from a tube preamp because it'll add “warmth” to the sound. However, if you're not targeting this audio, many people recommend using a solid-state preamp for a cleaner sound.

Drums

The go-to option is a tube preamp for drums to sound fatter because of the harmonic distortion presented. However, if you want punchier drums, a solid-state preamp could be a better choice.

After reading the above, you should have a more comprehensive idea of microphone preamplifiers' benefits in terms of audio. It's significant and undoubtedly worth every cent you invest into the device.