Home Resources Preamp vs. Interface [Definitive Guide]

Preamp vs. Interface [Definitive Guide]

by Stuart Charles Black
Published: Last Updated on
Universal Audio Volt 2 Review

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Hi friend and Welcome!

What is the difference between a Preamp vs. an Interface? Glad you asked.

It’s a super important question in determining which gear you decide to buy for your home studio! Before we get started though…

Grab a snack, sit back, and relax because…

You’ve come to the right place!!

What I will bring you in this article

  1. Introduction
  2. What is a Preamp?
  3. Does a Preamp Improve Sound?
  4. How to hook up an audio interface to an external preamp?
  5. Do you need a mic preamp if you have an audio interface?
  6. Does it matter what Audio Interface I use?
  7. Focusrite Scarlett 2i2
  8. What does an Audio Interface do?
  9. Top Recommendation/Final Word

Now without further ado, let’s get rolling!


You may have been shopping around for an audio interface when the term “Preamp” came up.

Now you’re wondering what the difference is, and do I need both or just one? Do interfaces come with built-in preamps?

All of these are great questions that I’ve had to deal with in buying gear myself.

It can be confusing and frustrating when starting out.

There are so many options available to us and I’ve been overwhelmed on more than one occasion. Today I’ll make it crystal clear!

What is a Preamp?

The purpose of a preamp is to amplify the low-level signal of your microphone, to a line-level signal.

Because microphones on their own operate like Charlie Chaplin, the gain must be used in order to amplify them to a listenable level.

From Neumann’s article on Why Do I Need A Preamp?

Microphone signals are usually way below the nominal operating level, so a lot of gain is required, usually around 30-60 dB, sometimes even more. Guitars and basses donโ€™t require quite as much gain, but often around 20-30 dB. Even line sources such as synthesizers may require some amplification to match studio level, because there are various standards. The old standard for home audio and semiprofessional devices is (or was) -10 dBV while professional devices operate at +4 dBu (due to different voltage references, the difference is not 14 dB but roughly 12 dB). Today, even inexpensive home studio gear is usually designed for a nominal level of +4 dBu, but electronic instruments still often work at -10 dBV or thereabouts. Nuemann

With that said, an Audio Interface usually provides built-in preamps, allowing you to bypass the headache of having to connect the two (it’s not that hard, we’ll discuss it in a sec).

Does a Preamp Improve Sound?

There are a few different reasons why you may want a preamp in addition to an audio interface.

Sound Enhancement.

This is a stand-alone unit with no direct computer connection. External preamps are often used to enhance vocals.

They will change and alter the sound (color it if you will).

External preamps have their own sound and have the ability to add a lot of flavor to your recordings via different tones, colorization, etc.

More Gain.

Another benefit of having a separate preamp is that it will provide more gain.

Audio Interfaces rarely provide more than 60dB, but some mics may require more.

A ribbon mic for instance would require more like 70dB or more, so it’s something to keep in mind.

In addition to that,

though I can technically use my Shure SM57 (a dynamic mic) with a Universal Audio Volt 2, it has just enough gain. In other words, I need a Fethead to really drive it.

If I really wanted to go all out, I would get a preamp, but you don’t necessarily have to do that.

That said, you’ll be fine with most entry to mid-level condenser microphones paired with a good interface.

Better Components.

The components in an external preamp are also usually of higher quality, and the power isn’t shared with other components.

It isn’t night and day but does make a difference in the grand scheme.

Once your ear starts to develop more, you’ll notice these small nuances in sound that can really make or break a recording.

How to hook up an audio interface to an external preamp?

A great question! There are really just 2 steps:

  1. Plug your microphone (using an XLR cable) into the preamp’s mic input.
  2. Run a 1/4 inch cable (TRS), from the output of the external preamp, into an available line input on your audio interface.

There are a couple of important reasons why it should be done this way:

  1. By using the outputs on the back, you’re bypassing the built-in preamps of the interface.
  2. If you try to connect the preamp to the front (i.e. front-panel mic/instrument/line input) you’ll only end up with a myriad of issues including but not limited to the following: weaker signal, a higher level of noise, ugly audio artifacts, etc. You could also damage the inputs on the front of the preamp, or the preamp itself!

A couple of final notes:

  • Since you’re using an external preamp to bring the mic signal to line level, you don’t need the gain on the audio interface anymore.
  • Turn the interface gain knob all the way down.
  • Adjust the gain on the external preamp from now on if you need more.

Do you need a mic preamp if you have an audio interface?

Not necessarily. If you’re just starting out, an affordable audio interface like the Focusrite Scarlett 2i2  or Volt 2 (mentioned above) will most certainly do the trick.

Both have built-in preamps, so you’re sort of killing 2 birds with one stone.

Are the internal preamps of an audio interface as good as a separate one? It depends.

For the entry-level stuff, no. But once you start getting into some of the higher-priced gear, they may be. It’s hard to say.

Sean Divine made a great video on why this stuff is important, and if you may or may not need a separate Preamp. Be sure to subscribe to his channel!

Does it matter what audio interface I use?

Sean would actually say yes. In the video, he talks about how he’s owned a lot of different interfaces over the years and that the quality of the conversion does vary.

Focusrite Scarlett 2i2

Chillin’ in-studio before I sold him ๐Ÿ™

For most people, a 2i2 or something similar will be perfect.

They’re convenient, will work with a bunch of different microphones, and come with USB capability.

The Scarlett 2i2 is a good example.

It works like a charm and is really easy to set up while also providing you with an array of options:

  • You can hook it up to active studio monitors. What are Studio Monitors?
  • It uses 48v phantom power for any microphone I may be using. Before I sold it, I had been using it with the fantastic entry-level AT2020 and Samson C01. Learn more: Audio Technica AT2020 condenser microphone review!
  • You can plug a headphone in via the 1/4″ jack on the front and essentially use it as a headphone amp. Don’t rely on it for real power-hungry headphones or planar magnetics though. What is a Planar Magnetic Driver?
  • You can record an instrument with it via the combo XLR/TRS jack on the front as well.

It’s important to understand that an audio interface is the most important piece of gear in your studio.

It’s essentially the link between you and your PC when you’re doing any sort of recording, playback, etc. with regard to mixing, monitoring, and everything else that comes with recording and producing.

What does an Audio Interface Do?

What does an audio interface do?

What does an audio interface do?

Glad you asked!

An Audio Interface is essentially a DAC.

It provides a Digital to Analog conversion, converting the digital 1’s and 0’s that your computer understands, into the analog sound that you understand.

This is most prominent with something like a Headphone Amp/DAC, where your computer is converting the digital recreation of the song into the sound your brain processes as sweet, sweet music.

This process also works in reverse.

When you speak, rap, or sing into your microphone (analog), it gets sent across the motherboard of your computer, is processed, and then the recording is played back digitally for your ears. This conversion happens in less than a second!

The AT2020 is a great entry-level condenser that pairs well with a Scarlett Solo or 2i2.

To recap what a Preamp does?

Preamps just boost the signal on your microphone to a listenable level (called line level). That’s it!

Just think of it as a giant volume knob turned all the way up.

The great news about audio interfaces is that the preamps used are clean and clear, and will do a fine job replaying back the recording at a loud enough level.

If you plan on using an interface, you can also tweak the sound in a different way (separate from the stand-alone preamp mentioned above).

Channel Strip/Processor

This could mean using different mics, experimenting with mic placement, or using plugins that add different effects to the sound.

A great example of an effects rack (or channel strip) that’s simple and effective is the DBX 286s.

This baby allows you to edit the sound of your voice essentially in real-time, by providing features like an on-board Compressor, De-Esser, Enhancer, and Expander/Gate. It’s great for folks who are more hands-on.

In the above video, Sean was using an Aphex Channel.

Built-in preamps that come with interfaces really get a bad time of it.

In reality, there’s nothing wrong with them. In fact, they are really the way to go in my opinion when starting out.

They work perfectly in many small bedroom studio setups or otherwise, and ooze quality.

Engineers 30 years ago would have killed to have the kind of equipment we spoiled producers have these days!

Down the road when you’ve got more experience under your belt, you can always add more pieces (like a preamp) and expand your sound capabilities.

Recommendations and Final Word

If you’re just starting out, I would go with an audio interface that has built-in mic preamps.

Before I had to sell it due to incompatibility issues with Windows 10 (after I purchased a new laptop), I used the 1st generation Scarlett 2i2 in my studio from 2014 – 2019 and loved every second of it.

I never felt a need to upgrade!

Focusrite has since come out with their 3rd generation line, but I now own a Universal Audio Volt 2 which is also an excellent product.

The Solo now utilizes balanced line-outs (like the 2i2) instead of RCA this time around, and has better sonics, lower latency, and enhanced ease of use.

The new “air” feature utilizes the same technology apparent in their top-of-the-line preamps, so you’ll be getting pristine quality and more headroom with various different mics (Ribbon Mics, etc.)

Remember how I said before that was one of the main reasons to purchase a separate preamp? You may not even need to do that now.

Learn more about the Solo:


Well, that’s about it for today friend. I really hope you have a clear idea of the Preamp vs. Interface and came away with some newfound knowledge!

Are you more inclined to purchase an audio interface or Preamp after this discussion? Both? Neither? Let me know!

Questions? Comments? Did I get something wrong or leave anything out? Leave a comment down below or contact me! I would love to hear from you…

All the best and God bless,





Be sure to check out my Reviews and Resources page for more helpful and informative articles!

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Brennan February 7, 2016 - 5:45 am

Hi! Thanks for the great post, I was deciding between the Focusrite Saffire 6 and the Scarlett and this post definitely helped ๐Ÿ™‚ This one seems a little newer and probably better quality. Do you think this is the best option for the money? Appreciate your response! Also keep the blog going, there’s a lot of good stuff in there! I’m trying to figure out how to record acoustic guitar right now

Stu February 7, 2016 - 5:09 pm

Hey there again!

I do believe the 2i2 represents the best price to performance ratio out there, and I’ll keep endorsing it until it dies. Lol. It’s just a really solid piece of equipment. Right now I’m actually listening to Death cab’s second album “We have the facts and we’re voting yes” and it makes a great pair with the JBL LSR 305’s.

For recording guitar and instruments in general, check out the MXL v67g vs. MXL 770. The v67g has been endorsed a lot for instruments, and makes a great starting point!

The Rode NT1A is also great for instruments, but a lot of people say not as good for vocals. A bit overrated if you will.

These are just off top. The AT2035 may be the best all around mic in existence at it’s price point. People really drool over that one.

Any other questions just ask!


Anon October 31, 2017 - 2:04 pm

Great article.
Saved me a lot of time and helped me figure out my actual needs ; things can get pretty confusing when you go on a read-only research about audio, and I got carried away by all the tech/advice discussions I’ve stumbled upon.
Thank you very much !

Stuart Charles Black October 31, 2017 - 2:46 pm

Your welcome Anon!

If you ever need anything down the road don’t hesitate to Contact me!


Taylor Bishop December 7, 2017 - 5:46 pm

Really nice article about preamps and interfaces. I didn’t know that you should really experiment with different mics and placements to find something that works. It kinda sounds like a fun way to help you get more acquainted with this equipment and can probably help you learn a lot.

Stuart Charles Black December 7, 2017 - 6:35 pm

Thanks for stopping by man!

Yeah I agree. I’ve been experimenting with my AT2020 lately and how close I get to it. I find that 6 inches away allows me to get a natural sound, but of course the gain is turned up at around 95%. If I were to turn the gain down, I could get closer without distortion. It’s really about finding a happy medium and trying different things. I would rather have to EQ my voice down by a few decibels than have to turn it up. That said, the 2020 gives a great first take, and has a very crisp character for under $100.

Let me know if you ever need a hand with anything. ๐Ÿ™‚

King January 17, 2018 - 6:30 am

Hello Stu, I have a pressing question, and I would really appreciate a professionals answer.
When I have my pre-amp connected to my 2i2 2nd gen, should I have the interface set to “Line” or Inst? Can’t find out anywhere ๐Ÿ™

Stuart Charles Black January 17, 2018 - 6:21 pm

Hey King!
Run a 1/4″ TRS from the line output of the preamp into the line input of the interface.

Let me know how it works. ๐Ÿ™‚


Mihai May 29, 2018 - 6:59 pm

Hello Stu!
I just bought my first studio monitors, are cheap because I donโ€™t know nothing about studio monitors, the speakers are PreSonus ERIS E5, but I read on the internet that this speakers are even good for listening music on them or for games!
So, I plugged my phone to speakers with 3.5 mm TRS to Dual 1/4 in TS, but the sound itโ€™s not that amazing!
Itโ€™s better if I connect the speakers first to any amplifier or audiobox?
Let me know! Thanks!

Stuart Charles Black May 31, 2018 - 5:18 pm

Hey Mihai!

Try the Scarlett 2i2 or Scarlett Solo and use balanced XLR to TRS if you can.

Let me know how it goes!


zande seeley December 11, 2018 - 6:12 pm

I am just starting out. Between the Scarlett, Presonus, Steinberg, and Komplete 6 Audio,
I chose the Komplete 6 Audio. 2nd choice would have been the Steinberg. I chose the Komplete 6 Audio. From what I read, top notch preamps, (must have) midi in and output, and the Software included, Cubase Le (DAW) Komplete Elements, etc, etc. A complete production package. I also purchased the package that included the MXL 990 mic and accessories. The Steinberg interface also had great software.

I was researching adding an analog preamp to the interface to see if that would be beneficial or not. Also I was wondering if some of the warmth from an analog signal would enhance the recordings. Your article popped up was explaining how to connect a preamp to the interface. Your explanation was simple for me to understand so I immediately saved your site to my folder RECORDING TIPS. If you can add any thoughts to the warmth addition to recording in digital, this would be very useful knowledge for all. Thank you, Zande.

Keep up the good work!

Stuart Charles Black December 13, 2018 - 7:37 pm

Thanks Zande! Your kind words are much appreciated. As for adding an analog preamp, yeah something like a tube preamp or even just an analog pre will warm up the sound so you may try it out. Which one were you thinking about going with?

Larry Deemer January 20, 2019 - 10:14 pm

How to hook up an external pre-amp?

2. Run a 1/4 inch cable (TRS), from the output of the external preamp, into an available line input on your audio interface.

I have an output on the DBX 286 but can’t find a “line input” on my Scarlett 2i2.
Any suggestions? Thanks.

Stuart Charles Black January 21, 2019 - 6:08 pm

Hey Larry! The input is actually on the front. It’s a combo XLR/TRS. Kind of confusing I know! Took me a second to remember. I have the 2i2 as well. Make sure the little switch is set to “line” right below the input and to the right. Hope that helps! Let me know. ๐Ÿ™‚

That’s awesome though. You recording some vocals I assume? I just got done laying down a couple verses and really wish I had the 286 lol. Check out the Mad Hermit’s excellent explanation on it and how it reduces noise. It’s incredible! https://www.youtube.com/watch?v=FEaivtPrBe0

Larry Deemer January 22, 2019 - 12:16 am

Thanks for the quick response. I found the answer yesterday on YouTube. Will check out the link you sent…maybe its the same one…

Stuart Charles Black January 23, 2019 - 1:28 am

Thanks man! I’m really considering getting the DBX 286 for my studio now thanks to you. Let me know how things go with the connection!

Allen Jones August 27, 2019 - 7:55 am

Hello, thank you for your informative post. I’m currently recording voice with a Studio Projects B1 condenser microphone and a Behringer Tube Ultragain Mic100. The Behringer calls itself a preamp, not an audio interface, but I’m able to plug my mic into it, and then from there into the computer directly. It seems to work just fine without an audio interface, though I’m noticing that the quality of the audio is sub-par. It’s decent, but not professional. Would connecting the preamp to an audio interface, and then the audio interface to the computer improve the quality of the sound to a professional level? Or would that have to do with my microphone? Or the software into which I am recording? I’m currently recording and editing in Audacity. Thanks in advance for any help you can be.

Stuart Charles Black August 27, 2019 - 4:03 pm

Hey Allen!

My pleasure! Yes, I would recommend getting a solid audio interface to start. You don’t really need a preamp at this point. Later on down the road you could invest in one to improve sound quality, enhance the sound, etc. but since you’re just starting out, a decent interface with good built in preamps should do just fine.

Also nothing to do with Audacity or your mic. Both are just fine to use! In fact I use Audacity myself. Your mic is also a great entry level condenser as well.

How are you connecting the Ultragain Mic100 to your PC if it’s just a preamp? You must have this separate version that comes with USB? The original does not. https://www.bhphotovideo.com/c/product/1286005-REG/behringer_mic500usb_audiophile_vacuum_tube_preamplifier.html


Tim April 25, 2020 - 6:21 pm

hi. In describing how to set up an external preamp with an audio interface you say
” Plug your microphone (using XLR cable) into the interfaces mic input.
Run a 1/4 inch cable (TRS), from the output of the external preamp, into an available line input on your audio interface.”

should that first sentence read “plug your microphone (using XLR cable) into the PREAMPS mic input? Probably a dumb question but your use of the word “interface” in that sentence has me a bit screwed up.

Stuart Charles Black May 4, 2020 - 5:59 pm

Hey Tim!

Yes you’re exactly right! That’s a definite typo. Thank you so much for the heads up!! I will fix it right away. ๐Ÿ™‚ Did you need some sort of preamp for a mic that requires more gain?

Amy November 19, 2020 - 11:01 pm

Hi Stu!
You mentioned a while back that Windows 10 didnโ€™t like one of your audio interfaces. Which one? Iโ€™m contemplating purchasing the Focusrite Scarlett 2i2 to use with my PC and Windows 10. By the way, Iโ€™m a complete newbie starting to record my own VOs.

Stuart Charles Black November 21, 2020 - 3:36 am

Hey Amy! It was the Scarlett 2i2 1st gen, which is understandable. I’ve since sold it and I’m going to get a 3rd gen solo or 2i2 I think ๐Ÿ™‚

I would highly recommend a 2i2!!! Which mic are you thinking of, or already have?!


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