PreSonus vs Focusrite Audio Interface: Model By Model Comparison

The centerpiece is an audio interface when it is about the studio or home audio.

An audio interface simply converts the signals and is used for recording or playback. And everyone wants a good interface for their home or studio. The main problem arose while choosing an entry-level audio interface.

Among several brands, we are going to review PreSonus VS Focusrite Audio Interface; to make your choice easier and shorter. These two brands are well-known in the audio hardware world.

We have enlisted some of the best products from these two brands and compared them, model by model.

This will help you to understand better and make a wise choice. So, stick to us to get some new experience.

PreSonus vs Focusrite Audio Interface At A Glance

PreSonus Audiobox USB 96: Budget-friendly

PreSonus Studio 68c : More mic-preamps, good sound

PreSonus Studio 1824c: The best option for a small home studio

PreSonus Studio 26c: Powerful software tool, high-resolution audio.

Focusrite Scarlett 2i2: Affordable

Focusrite 8i6: Versatile connectivity option

Focusrite Scarlett 18i20: Great alternative to 1824C

Focusrite 4i4: Decent choice for guitarist, musicians, podcasters

PreSonus VS Focusrite Audio Interface: Which Is Better?

PreSonus is a familiar brand name for the music producer, podcaster, and content creator. This brand has dedicatedly brought a lot of great audio interfaces and successfully could have impressed the consumer with the performance.

All the PreSonus audio interfaces contain good analog and digital I/O, with good quality mic preamps, phantom power, and, most importantly, great sound.

Comparing the price range PreSonus always try to offer the best in a budget-friendly option

 

In contrast, we can say Focusrite’s audio interface is like the identical brother of PreSonus. While reviewing the products, we explore so many similarities between them.

With Focusrite, you will still find universal connections, enough mic-preamps, and other rich features.

The similarities are the main thing that makes our decision more challenging. That is why we decided not to find out which is better or something; instead, we will explore each audio interface’s unique feature so that you can choose the right one.

PreSonus VS Focusrite Audio Interface Model By Model Comparison

Now it’s time to see the real-world difference by comparing PreSonus and Focusrite Audio Interface products. These two brands’ audio interfaces contain some similarities and unique features.

We will compare some of the most debated products. The price range will also vary, and you have to choose according to your budget.

This section will help you know the fundamental differences to understand which will fit your or your home studio.

PreSonus Audiobox USB 96 VS Focusrite Scarlett 2i2: Affordable Audio Interfaces

Features
PreSonus Audiobox USB 96
Focusrite Scarlett 2i2
Connectivity
USB-B
USB-C
MIDI In/Out
YES
NO
Sample rates
44.1kHz 48kHz 88.2kHz 96kHz
44.1kHz 48kHz 88.2kHz 96kHz 176.4kHz 192kHz
Phantom Power
+48V
48V
Mic Gain Range
60 dB
56 dB
Mic Input Noise
-116.5dBu EIN
-128dBu
Monitor Dynamic Range
97.6 dB
108dB
Headphone Dynamic Range
N/A
104dB
MacOS, iOS
YES
YES
Includes
2 Class-A Mic/Instrument Preamps
2 Focusrite preamps
Features
PreSonus Audiobox USB 96
Connectivity
USB-B
MIDI In/Out
YES
Sample rates
44.1kHz 48kHz 88.2kHz 96kHz
Phantom Power
+48V
Mic Gain Range
60 dB
Mic Input Noise
-116.5dBu EIN
Monitor Dynamic Range
97.6 dB
Headphone Dynamic Range
N/A
MacOS, iOS
YES
Includes
2 Class-A Mic/Instrument Preamps
Features
Focusrite Scarlett 2i2
Connectivity
USB-C
MIDI In/Out
NO
Sample rates
44.1kHz 48kHz 88.2kHz 96kHz 176.4kHz 192kHz
Phantom Power
48V
Mic Gain Range
56 dB
Mic Input Noise
-128dBu
Monitor Dynamic Range
108dB
Headphone Dynamic Range
104dB
MacOS, iOS
YES
Includes
2 Focusrite preamps

Product Description

PreSonus Audiobox USB 96 VS Focusrite Scarlett 2i2 are two affordable audio interfaces a perfect solution for a home studio. Those new to using an audio interface can have any of these for the ultimate recording or playback purpose.

Now, let’s see which is suitable for you.

  • Audiobox USB 96 is a fantastic audio interface that comes with impressive features compared to the price range. Under $100, this product is something that will definitely surprise you.

Though it has a backdated look that many may don’t like, it is rich in quality features. For podcasters, musicians, or singers, recording at home with high-quality audio clarity is much easier with this interface.

This converts high-resolution audio both for DA or AD. It supports 24-bit conversion up to 96 kHz sampling rates. This means it also works as a dedicated DAC, and you don’t need to spend extra on a DAC anymore.

Coming to connectivity, it has versatile connection options. There are two input combo jacks in the front to connect TRS/XLRS with separate knobs for adjusting volume. For the headphones or speakers, use the two ¼” line outputs.

Additionally, on the backside, get 5-pin MIDI I/O, phone port, and USB port for connecting the PC.

The most exciting part of this interface is the DAW software works both for windows and Mac. Studio One Artist DAW is the most popular in the market because it enables you to create your beats.

  • Another hand, Focusrite Scarlett 2i2 is another excellent audio interface. It provides high-frequency sound with updated features, making it perfect for guitarists, musicians, podcasters, and mostly content creators.

Featuring 24-bit at a sampling rate of 192 kHz, this is both an AD and DA converter. It converts signals with high precision and clarity that produce high-resolution audio.

It can capture signals from any type of source and still will provide crystal-clear audio. The high-resolution conversion makes all that happen.

Now, about the connectivity, it has a pretty straightforward setup without a messy connection. There are ¼” XLR and TRS jacks on the front side. Those two XLR combo inputs let the user record distortion-free, clear recording.

Also, enable to acceptance of signals from guitar such as any electrical instruments or even from line-level sources. Also, get signals from drum machines.

Use the ¼” headphone jack which is located on the front panel for headphones or earphones. There are the separated volume knobs for the monitor and headphones for an independent controlling option.

Last, of all, there is a phantom knob, line switch, and central output knob with a gain knob on both sides.

The most attractive part about this audio interface is the two improved Scarlett mic preamps. These preamps are used for live recordings.

Overall, this is the best option for capturing high frequency and providing high-resolution recordings.

Which Is Better?

It is really tough to find out which is best, that’s why we prefer to choose the better option.

Both audio interfaces have the same build quality, and there is no winner in this criterion. Supporting DAW, feature preamps and the compatibility with MAC and windows are also alike.

But the difference arose with MIDI compatibility, as Focusrite does not support it. But Focusrite supports 24bit/192 kHz, which produces clearer high-resolution audio.

Ultimately, both of these devices are best in their ways.

PreSonus Studio 68c VS Focusrite 8i6

Features
PreSonus Studio 68c
Focusrite 8i6
Connectivity
USB Type-C
USB Type-C
Maximum Sampling Rate
192 kHz / 24-Bit
192 kHz / 24-Bit
Number of Microphone Preamps
4
2
Phantom Power
48V
48V
MIDI I/O
1 x DIN 5-Pin Input (on Breakout Cable) 1 x DIN 5-Pin Output (on Breakout Cable)
1 x DIN 5-Pin Input 1 x DIN 5-Pin Output
Channels of I/O
Analog 4 Inputs / 4 Outputs, Digital 2 Inputs / 2 Outputs
Analog 6 Input / 4 Output, Digital 2 Input / 2 Output
Features
PreSonus Studio 68c
Connectivity
USB Type-C
Maximum Sampling Rate
192 kHz / 24-Bit
Number of Microphone Preamps
4
Phantom Power
48V
MIDI I/O
1 x DIN 5-Pin Input (on Breakout Cable) 1 x DIN 5-Pin Output (on Breakout Cable)
Channels of I/O
Analog 4 Inputs / 4 Outputs, Digital 2 Inputs / 2 Outputs
Features
Focusrite 8i6
Connectivity
USB Type-C
Maximum Sampling Rate
192 kHz / 24-Bit
Number of Microphone Preamps
2
Phantom Power
48V
MIDI I/O
1 x DIN 5-Pin Input 1 x DIN 5-Pin Output
Channels of I/O
Analog 6 Input / 4 Output, Digital 2 Input / 2 Output

Product Description

PreSonus Studio 68c vs Focusrite 8i6 are two great audio interfaces for studio-like recording and playback facilities. Both have several similarities, but 8i6 has performed slightly better to some extent.

  • By offering a studio-quality performance, PreSonus Studio 68c is a combination of versatile connection and ultra-high-definition sound. This is the ultimate solution for podcasters, musicians, or others for recording or mixing.

This audio interface supports all the rich features for delivering an iconic performance, whether as a converter or DAC. It supports 24 bits at 192 kHz, ensuring the high-resolution sound quality for recording and playback. This converts each bit with pure clarity and works best both as DA/AD.

Next, it is equipped with four XMAX Class-A mic preamps. These mic-preamps are known for the high headroom, smoother highs, and deeper lows with the lowest noise.

Measuring phantom power 48V, this converter accepts signals from electrical devices, drums, keyboards, and many more devices.

Talking about the universal connection options, this converter has 6-in and 6-out, two combos mic/line/instrument I/O, and S/PDIF digital I/O. There are also four ¼” TRS with MIDI I/O.

To connect your speaker or headphone, use two 1/4″ mainline/monitor outputs and stereo headphone output. Adjust the volumes separately with different knobs from the front panel.

Here, just note one point is that all four outputs of this interface are DC coupled.

Lastly, Studio One Artist DAW integrated software lets you record with thousands of software, with excellent compatibility with macOS and Windows.

  • Plug in your music-making devices and producing studio-like sound by sitting in your home is no longer a dream. Now cherish and full fill your dream with Focusrite 8i6’s sonic performance.

This is superb audio interface comes with 8-in and 6-out versatile connectivity. When we use the term versatility or universal connection option, you should be assured at that moment. Because with this kind of converter, you don’t need to worry about connecting your music devices. Just plug in and record.

First of all, the most exciting part about this device is the two-third GEN preamps, which is something best that ever happened to Scarlette. These improved mic preamps enhance the performance a lot.

Additionally, this preamp is equipped with phantom power, allowing the device to transmit signals coming from any electrical instruments. This also reduces distortion as much as possible with an Air mode for a more expansive sound.

There are six balanced line inputs and four balanced outputs for connecting the devices. Both the I/O modules work dedicatedly so they can both accept and produce crystal clear signals.

You can connect your headphone, earphone, computer, or other devices with the ¼” inputs. There are also volume control knobs separately so that you can adjust them according to your need.

However, this device supports 24 bits at a sampling rate of 192 kHz for the high-resolution audio. This feature is similar to PreSonus. You can expect a high-fidelity and spacious sound stage.

Overall, this device is worthy in every aspect, and for the price range, this is actually offering a bit more.

Which Is Better?

In a specific word, 8i6 offers more connectivity options so that the user can connect to more devices. Other than that, all the features are almost identical in both audio interfaces.

That’s why we are considering Focusrite a slight winner; both have given the most challenging competition to each other.

PreSonus Studio 1824c VS Focusrite Scarlett 18i20: Best Option For Small Home Studio

Features
PreSonus Studio 1824c
Focusrite Scarlett 18i20 
Sample Rate
24-bit 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz
24-bit 44.1kHz-192kHz
Number of Preamps
8
8
MIDI I/O
YES
YES
S/PDIF I/O
YES
YES
Mic/Line/Instrument dynamic range
110dBA/112dBA/112dBA
111dBA/110.5dBA/110dBA
Inputs
2 combo mic/ line/instrument, 6 combo mic/line, 8 channels ADAT Optical
6 combo XLR/jack mic/line inputs, 2 front-panel XLR/jack mic/line/instrument inputs
Outputs
2 balanced ¼” TRS mains; 8 balanced ¼” TRS line, 2 ¼” stereo headphone outputs with independent mix streams, 8 channels ADAT Optical
10 TRS jacks, 2 independent headphone outputs, S/PDIF x 2/ADAT x 8
Features
PreSonus Studio 1824c
Sample Rate
24-bit 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz
Number of Preamps
8
MIDI I/O
YES
S/PDIF I/O
YES
Mic/Line/Instrument dynamic range
110dBA/112dBA/112dBA
Inputs
2 combo mic/ line/instrument, 6 combo mic/line, 8 channels ADAT Optical
Outputs
2 balanced ¼” TRS mains; 8 balanced ¼” TRS line, 2 ¼” stereo headphone outputs with independent mix streams, 8 channels ADAT Optical
Features
Focusrite Scarlett 18i20 
Sample Rate
24-bit 44.1kHz-192kHz
Number of Preamps
8
MIDI I/O
YES
S/PDIF I/O
YES
Mic/Line/Instrument dynamic range
111dBA/110.5dBA/110dBA
Inputs
6 combo XLR/jack mic/line inputs, 2 front-panel XLR/jack mic/line/instrument inputs
Outputs
10 TRS jacks, 2 independent headphone outputs, S/PDIF x 2/ADAT x 8

Product Description

Studio 1824c comes earlier than Focusrite 18i20 but is highly similar in features. So, let’s find out the dissimilarities between them.

  • PreSonus Studio 1824c is designed with advanced techniques and a universal connection that can take your recording experience to the next level. Additionally, onboard monitor mixing and pristine mic preamps make a combination with other features so you can record ultra-high-definition sound.

This box contains a metallic body with a black and blue color combination, and the connection option on it is pretty organized.

You will get both USB C-C and USB C-A 2.0, so you can connect your PC or devices easily.

There are 8 XLR/TRS combo jacks, including two combo mics with switchable instrument/line inputs and six line/mic inputs, 8 XMAX Class-A mic preamps, plus +48V phantom power for analog inputs.

For the outputs, there are 10 TRS outputs, where two works are for headphone connection and have separate volume control knobs, and another two outputs for monitors.

Also, all eight available outputs are DC coupled.

There is the MIDI interface to allow connection with the keyboard or sound module. Digital inputs include stereo S/PDIF I/O with eight ADAT Optical I/O channels.

For producing a fantastic sound, this interface works with 24-bit/192 kHz and eight mic preamps. You will get the remarkable sound and wish to record it repeatedly.

For the guitarist, music producer, or podcaster, this is something premium quality audio interface for getting placed into their studio.

  • Perhaps you are astonished by 1824C this far, but now you will see another extremely interface that is 18i20. For those who want a studio-like recording experience in their home and are ready to spend around $500, this model is for them.

This pretty professional audio interface comes with a metallic body structure and black coating on it. There are red borders, and plenty of the ins and outs let you enjoy the sound without hassle.

The USB 2.0 for connecting PCs and 8 combos XLR/TRS input jacks include two switchable line/instrument inputs that work as analog connectivity.

With four outputs for the monitor with an Alt button for switching between them, two headphone outputs, and individual control over them, there is a total of 10 TRS analog outputs available.

Supporting MIDI I/O, there are S/PDIF and ADAT connections for Digital I/O.

Apart from the connections, you will get 8 mic preamps, and an Air Mode for a broader sound system is available.

This interface also supports 24bit at a sampling rate of 192 kHz.

Overall, all the features and techniques are enough for a small studio recording or playback at home. For the content creator or podcaster, this piece of hardware is going to be on the top list.

Which Is Better?

1824c includes 8 XMAX Class A preamps, DC-coupled outputs, and Studio One Artist Software for recording with many software. These are the features that are not present in 18i20.

Whereas 18i20 includes Air mode, talkback mic, and so on.

Apart from these features, both interfaces are similar. So, it actually depends on you which you want to choose or like.

PreSonus Studio 26c VS Focusrite 4i4

Features
PreSonus Studio 26c
Focusrite 4i4
USB
USB TYPE C
USB TYPE C
Sampling Rate
192 kHz / 24-Bit
192 kHz / 24-Bit
Number of Microphone Preamps
2
2
Phantom Power
48V
48V
MIDI I/O
YES
YES
OS Compatibility
MacOS, Windows
MacOS, Windows
Analog Audio I/O
2 x Combo XLR-1/4" TRS Balanced/Unbalanced Mic/Line/Hi-Z Input, 4 x 1/4" TRS Balanced Line/Monitor Output (DC-Coupled), 1 x 1/4" TRS Unbalanced Headphone Output
2 x Combo XLR-1/4" TRS Balanced/Unbalanced Mic/Line/Hi-Z Input (Front Panel), 2 x 1/4" TRS Balanced Line Input, 4 x 1/4" TRS Balanced Line Output, 1 x 1/4" TRS Unbalanced Headphone Output (Front Panel)
Features
PreSonus Studio 26c
USB
USB TYPE C
Sampling Rate
192 kHz / 24-Bit
Number of Microphone Preamps
2
Phantom Power
48V
MIDI I/O
YES
OS Compatibility
MacOS, Windows
Analog Audio I/O
2 x Combo XLR-1/4" TRS Balanced/Unbalanced Mic/Line/Hi-Z Input, 4 x 1/4" TRS Balanced Line/Monitor Output (DC-Coupled), 1 x 1/4" TRS Unbalanced Headphone Output
Features
Focusrite 4i4
USB
USB TYPE C
Sampling Rate
192 kHz / 24-Bit
Number of Microphone Preamps
2
Phantom Power
48V
MIDI I/O
YES
OS Compatibility
MacOS, Windows
Analog Audio I/O
2 x Combo XLR-1/4" TRS Balanced/Unbalanced Mic/Line/Hi-Z Input (Front Panel), 2 x 1/4" TRS Balanced Line Input, 4 x 1/4" TRS Balanced Line Output, 1 x 1/4" TRS Unbalanced Headphone Output (Front Panel)

Product Description

  • Ultra-high-resolution sound, ease of recording or mixing, and playback PreSonus Studio 26c are among the best choices. This converter is capable of giving tough competition to other high brand interfaces.

This is featured with two XMAX mic preamps that allow you to record clear audio with 48V phantom power. For producing precise audio, it supports 24bit/192 kHz digital resolution. Get the pure clarity in your audio every time you record something.

For any type of condenser microphone, there is ¼” XLR input, both balanced and unbalanced, ¼” headphone output for your speaker and headphone, plus two-line outputs and mainline/monitor outputs.

You will get an individual volume control knob for your speaker and headphone.

The 5-pin MIDI I/O jack is integrated into the rear panel for the guitarist and bass.

There is both USB Type C and Type-A connection to connect your PC.

In a word, this is a powerful package within a decent price range.

  • Focusrite 4i4 is another impressive audio interface containing many similarities with 26C but offers more connectivity options. This device lets the musician record anywhere, anytime, in a flexible way.

This third-generation 4i4 audio interface performs like a boss and provides UHD quality, high-resolution audio to record.

It can make both capture vocal and instrument sound with the highest clarity: high headroom and lowest distortion. What else does one need in their recordings?

Two updated preamps, switchable phantom power, work with universal connection.

Whether you want to record from a drum machine, guitar, electrical machine, or bass, two XLR ¼” inputs allow you to do that. Moreover, there accommodates four balanced 1/4″ line outputs, a 1/4″ stereo headphone jack. Of course, you will have the advantage of controlling volume separately with the Focusrite interface.

Like any other good quality interface, this one also supports 24bit/192 kHz resolution.

Other features include MIDI I/O, powerful software tools, windows compatibility, and so on.

Which Is Better?

Focusrite 4i4 has more input-output options than PreSonus 26c.

PreSonus VS Focusrite: Product Review

Let’s review some more options from PreSonus VS Focusrite. We have shown you a detailed comparison of the most debated products. Now, you can better understand and get the perfect one for you.

But in case you want something different, then have a close eye on our next product review section.

PreSonus Quantum 2626 26×26 Thunderbolt 3 Audio Interface

Thunderbolt Audio Interfaces are considered one of the fastest interfaces in the world for the most obvious reason. This kind of interface is compatible with round trip latency of less than 1ms!!!

To provide you with the best experience, PreSonus brought this Quantum 2626 Thunderbolt 3 Audio interface. Be ready to enjoy an exciting recording experience with 26ins and outs. Just use the ADAT optical to get full access over 26 I/O.

Make faster and quality music from your DAW and any plug-in device. 24-bit/192 kHz is going to impress you with detailed, mesmerizing sound quality.

There will be the lowest distortion with a 115 dB dynamic range for you to record the smoothest sound form ever.

8 XMAX Class A mic preamps work simultaneously and promisingly to add more richness to the sound.

Last, of all, this device is compatible with both macOS and Windows. Also, you get the advantage of Studio One Artist software that makes your interface work with a thousand recording software.

If you want a premium quality audio interface from PreSonus, then check out this outstanding device.

PreSonus AudioBox GO

If you are not into some expensive audio interface and want to have a primary interface under $100, then you should check this AudioBox GO device.

This is one of the super affordable audio interfaces you can ever get for home and mobile recording.

This converter has sufficient input-output connections, featuring a PreSonus XMAX L mic preamp, +48v phantom power, and 50 dB gain.

The level-line combo jack input and instrument input let you connect keyboards, drums, guitar, and so on.

Use the headphone 1 TRS ¼” output port for headphone connection and listen to clear, detailed music. Two balanced TRS ¼” main output is present for the speaker.

You will get Studio One Prime DAW and Studio Magic software for recording. These software’s are ready to use anytime you want.

Now about the compatibility, this device can work both with Android and Apple. So, nothing matters whether you are an android user or an Apple user. Just enjoy a versatile recording by sitting at your home.

Focusrite solo

This Focusrite third-generation USB audio interface lets the user record studio-like audio, performs as an outstanding converter, and supports all the software needed for a versatile recording.

Record with you Focusrite Solo like the professional studio because it features the best mic preamps. Your recording experience would be the finest and most realistic with those mic preamps.

To widen the sound, it also features Air mode. So, you can get the extra punch in your new creation.

Next, there is no need to compromise with your guitar or electrical instruments. This device allows to take high-quality signals and capture them without any distortion or noise.

For your speaker or headphone, this again hit the punch. Plug in and enjoy high-fidelity audio from your phone or from a streaming app.

Now, if you are worried about the compatible software tools, then just be assured by knowing this; it supports plenty of software and other devices. There will be no problem with the recording or making your new creative audio.

Focusrite Clarett+ 4Pre 18-in / 20-Out

For the music makers who want to have such a premium quality audio interface that can promisingly record and mix music with high-definition sound, nothing can be the best choice than Focusrite Clarett+ 4Pre.

This converter or interface is the ultimate solution for capturing detailed sound with high headroom lowest distortion and noise. Your recording or mixing will be defined and clear every time.

This is both A-D and D-A converter, producing incredible sound with a high dynamic range. Moreover, the high-quality mic preamps for delivering precise sound.

Get four microphone inputs and two instrument inputs with eight-line inputs. There are two dedicated headphone outputs and four-line outputs for the analog output. This also enables the MIDI interface for the keyboard or other modules.

After all these descriptions about this fantastic audio interface, we can finally say this is something for delivering the next level high defined performance. Work like professionals with its professional quality service.

Focusrite iTrack Solo

With Focusrite iTrack Solo, it is too simple to record or make your music professionally. Because of the affordable price range and decent performance, it is popular among musicians.

Plug in your instruments or mic to instantly start and get the high-defined sound. The recorded sound is clear and distortion-free, with the lowest noise.

When we say this device is simple to use, we mean it. There is fewer connection option, but you can connect any of your devices. Also, power it using only the USB.

Moreover, not only for recording, use this interface to enjoy music, movies, or games just by connecting your speaker.

1 XLR mic input, unbalanced ¼” 1 instrument input, two gain knobs, monitor switch with a phantom power knob is located on the front panel.

You will get two unbalanced monitor outputs on the rear panel with a USB 2.0 port.

All these really make it worthy of getting some praise and also a money saver.

Final Verdict

Audio interfaces are a prerequisite when it comes to playback or recording. Today’s modern interfaces work as an excellent converter A-D/ D-A or sometimes like a DAC.

Today we have reviewed two popular brands PreSonus VS Focusrite Audio Interfaces. There are both expensive and affordable interfaces on our list so that everyone can have one according to their ability.

But remember one thing is for sure whether the interface is expensive or not, you will get the high-quality performance with each one.

For a clear understanding, we have compared some most debated devices from the marketplace. If you were in confusion, all your confusion must have cleared this far.

Also, we will review some more items for you in case you want to explore something different.

Now, the decision is all yours which to choose. According to your need and budget, choose wisely because an interface costs a reasonable amount. Then make your own creative music.

FAQ

This faq is here to solve some of your problems regarding these headphones.

Why is an interface actually needs for?

An audio interface is required for recording, mixing, or playback. If you are a musician, guitarist, or someone from this kind of background, then you are familiar with an audio interface.

The audio interface also converts analog; digital conversion also works as a DAC.

Do you need an extra headphone amp if you have an audio interface?

Generally, an audio interface comes with at least one headphone output and volume control with it. So, in that case, you don’t need an extra headphone amp.

How soundcard and audio interfaces are different?

The main difference is that soundcards are pre-installed with the motherboard, whereas audio interfaces are used externally.

Both converts digital to analog or analog to digital signals. But interfaces are also used for recording or mixing.