Fosi Audio K5 Pro Review — Gaming DAC Amp that packs a punch

Damian Cooper
11 min readApr 10, 2024
This is our Fosi K5 Pro

You’ve just had a terrible meeting with either your boss or one of prospective customers (or both) and you just wanna relax in the hotel and listen to some music (or play some games) and let all your worries float away into the abyss of happiness but… you can’t because don’t have the right equipment. Not anymore, sit down, grab a cup of coffe and discover the power of the Fosi Audio K5 Pro, a gaming DAC amp that elevates your audio experience, whether for gaming or relaxation, with unmatched quality and versatility.

Introduction: Unveiling the Fosi Audio K5 Pro

In the world of gaming and music, the quest for the perfect sound is endless. Enter the Fosi Audio K5 Pro, a DAC+AMP combo that promises to transform your audio experience. Whether it’s a tough day at work or a moment of leisure, this device stands ready to immerse you in a world of auditory bliss.

What’s a DAC and do we need it?

Digital-to-Analog Converters (DACs) play a crucial role in our digital age, converting digital audio files into the analog sounds we love. The evolution from vinyl and tapes to digital media has made DACs indispensable for pure, unaltered sound quality.refers to a digital-to-analog converter. It converts digital information into an analog audio signal. The music you hear through a CD player or on your smartphone is an analog signal that originated from a digital file.

The popularity of DACs surged in the early 1980s with the advent of compact discs. CDs enabled digital recording in studios, offering a more convenient alternative to the analog recordings that necessitated a tangible copy.

Looks sleek on your table

In the past, when vinyl records and cassette tapes were the primary means of listening to music, DACs weren’t necessary. This is because the music was always in analog form, from recording to playback.

However, analog technology has its limitations, particularly as newer devices often require digital connections like 3.5 mm jacks or USB cables to play our favorite albums. Thus, to bridge the gap between analog audio and digital technology, digital-to-analog converters have become essential for enjoying music without compromise.

There are stand-alone DACs, but we will talk today about a DAC with a built-in amplifier. But let’s talk about what DACs bring to the table.

Benefits of DACs

  • better sound quality
  • reduced noise
  • less distortion
  • lower latency (very important during your MM3 sessions on discord!)
  • higher sound detail (you know you can benefit hugely from that while gaming, don’t you?)
  • potential for equalization
  • more control over the sound
  • it’s small and portable
  • a gaming DAC usually splits microphone and headphones
  • can be used with multiple devices (smartphones, PCs, Macs, TV sets, gaming consoles
Fosi K5 Pro use case

All in all, a digital-to-analog converter (DAC) enhances audio experiences, allowing listeners to not just hear fundamental sounds such as footsteps and gunfire but also to identify their direction and distance. By processing audio signals more effectively than standard built-in sound cards, DACs minimize latency, guaranteeing that critical in-game sounds are heard in real time. They are just like high-end stand-alone sound cards that you can carry with you, period.

So, let’s talk about a very good entry level DAC — Fosi Audio K5 Pro.

The Specs

>Input : USB Type-C, Optical, Coaxial, Microphone

>Output : 3.5mm Headphone, RCA

>PC-USB supports input sampling rate: Up to 24Bit/96kHz

>Optical/Coaxial supports input sampling rate: Up to 24Bit/192kHz

>RCA Output Level: 2V

>Power Supply:5V

>Power Input Interface: USB Type-C

>THD: <0.003%

>SNR: ≥110dB

>Frequency response: 20Hz-20kHz (±3dB)

>PC-USB support operating system: XP/W7/W8/W10/MAC/linux

>Distortion: 0.001%;

>Amp output maximum power: 1000mw/16Ω, 500mw/ 32Ω, 300mw/64Ω, 150mw/128Ω, 80mw/300Ω

>Headphone matching impedance: 16–300Ω

>Size (L*W*H): 4.4*3.7*1.2inch (112*95*30mm)

>Net Weight: 0.551b/251g

What’s in the Box?

This is what you get in the box

I’m really fond of the innovative cables that numerous companies are starting to produce. They feature a versatile adapter on one end which is detachable, allowing the choice between USB-C or the inclusion of a USB-A adapter as necessary. Additionally, the inclusion of an optical cable in the package was a pleasant surprise. It’s impressive that they’ve decided to include this as well. The package also contains a headphone-mic splitter, a handy piece of hardware for those with existing gaming headsets. This splitter separates the microphone and headphone signals. and this setup allows for a straightforward connection to the dual 3.5mm inputs on the Fosi Audio K5 Pro, effectively preparing your gaming setup for immediate use.

The headphones used for testing

  • Audio-Technica ATH-M50X (closed-back)
  • Sony WH1000 xm3 (closed-back, higher bass)
  • Sennheiser HD 555 (open-back)
  • Iphone regular IEM
Useful info for you

Hardware used to test the DAC

  • a PC with onboard sound card + Xonar DGX
  • MacBook Air
  • MacBook Pro
  • Iphone 13
  • Iphone SE 2020

Mind you, I had to go with the original Apple OTG Lightning-USB adapter (a rather costly one), because 3rd party units just wouldn’t work. Apple, is another of your software tricks to limit 3rd party accessories use?

The Tech Inside

Exploring the technical specifications reveals the Fosi Audio K5 Pro’s versatile connectivity options, including USB-C, optical, and coaxial inputs, each supporting different sampling rates. The device caters to a wide range of audio fidelity preferences: for USB-C connections, it offers a 24-bit rate up to 96 kilohertz, while for optical and coaxial connections, the sampling rate increases to 24-bit up to 192 kilohertz, providing enhanced audio clarity. It accommodates headphones with impedance ranging from 16 to 300 ohms, underscoring its compatibility with a broad spectrum of headphones, from lower to very high-impedance models.

The output power varies significantly across the impedance range, from 1,000 milliwatts at 16 ohms to 80 milliwatts at 300 ohms. This range proved sufficient to power all my headphones to a level that was audibly rich yet comfortably volumed, highlighting the device’s capability to drive headphones with varying power needs effectively.

The sound experience

I delayed writing this review as I got carried away testing numerous headphones with it. The Fosi Audio K5 Pro is an ideal match for any affordable headphones you own, enhancing them to deliver a remarkable auditory experience. However, with cheap headphones the sound effect will not be that impressive, yet still much better than original. When comparing the output directly from my MacBook Pro, iPhone, or even my old Sennheiser HD555, the performance of this device stands out impressively for its ability to enhance clarity and uplift the overall audio experience with mid-range headphones.

Each pair of headphones showcased a significant improvement, when used with the Fosi Audio K5 Pro. Among them, the Sony WH1000 xm3 stood out because of their notably enhanced bass and enjoyable sound quality.

Small like a pack of bigger cigarettes

These headphones presented a brighter, more lifted, and fuller sound, making them exceptionally enjoyable with the Fosi Audio K5 Pro. I found great joy in hopping between songs, each time greeted with a smile, starting with the energetically charged “Enjoy the Silence” by Depeche Mode and finishing the session with “Random Access Memories” from Daft Punk. The track was infused with reverb and airiness, qualities that were distinctly amplified through each headphone I tested.

The standout feature of the Fosi Audio K5 Pro lies in its adjustability, with bass and treble controls on the front panel, making it exceptionally versatile for any audio content. Normally, I prefer my settings unaltered, yet pairing the Fosi with budget headphones and having the flexibility to modify bass and treble levels proved to be a game-changer, enhancing the audio quality of every pair of headphones I tested. The bass and treble knobs feature a notch at the 12 o’clock position to indicate when they are set to their neutral off positions. However, an area for potential improvement is the alignment of these notches; they are not perfectly vertical on both knobs. This slight misalignment impacts the device’s perceived quality, particularly for those with a keen eye for precision. While this is primarily an aesthetic concern, it stands out to individuals attentive to detail.

At very high volume levels, there’s a minor presence of white noise in the background, though this occurrence is infrequent and usually negligible, as the music or audio content typically masks it. This slight noise is not noticeable at regular listening volumes and does not significantly impact the overall audio experience

Moreover, the power output of the device was notably strong. Headphones with lower impedance levels were audibly louder, and it efficiently powered the Sony WH1000 xm3 headphones to a commendable high volume, showcasing the unit’s robust amplification capabilities.

I tend to repeat Sony’s headphones in this review, but that’s because I almost fainted when listening to powerful songs with some enhances bass there. However, my gaming Audio-Technica ATH-M50X headphones turned out to love the Fosi as well, but I use them mostly for gaming. And let me tell you, this DAC really delivers when gaming, but that’s its primary target audience — the gamers, isn’t it.

The gaming experience

The bass and treble controls on the device provide a significant advantage for tailoring the sound output to your preference, crucial for balancing audio frequencies according to the characteristics of your headphones. These adjustments are particularly beneficial when dealing with headphones that might either lack bass or treble or have overly harsh highs. The ability to swiftly modify the bass and treble settings ensures you can fine-tune the audio for the most enjoyable listening experience. This is very important in QuakeWorld for instance: the bass overload can really deceive you and hide all those other sound cues you’re desperately trying to hear. In such cases, the ability to dial back the bass and increase the treble directly from the device enriches the audio experience, making subtle sounds like footsteps in games more perceptible. This on-the-fly adjustment capability is invaluable, eliminating the need for external software solutions that can become outdated, unsupported, or cause system instability.

My advice though: turn down bass for Quake and other FPS shooters.

And this DAC can split your mic from your headset with the enclosed splitter cable — do that ASAP if you are on a headset to improve your discord sessions even more!

Bullet Points

  • good build quality
  • solid power input
  • very portable
  • elevated each pair of headphones I tested with it, including IEMs
  • easy to use, no drivers required, just plug and play
  • bass and treble controls are very welcome here
  • great value for money
  • elevates your sound experience in gaming, especially with sound cues and 3D
  • from an audiophile perspective, it may not include the most advanced decoding technologies available, but as indicated on its front panel, this device is designed as a gaming DAC, and it fulfills this purpose admirably
  • the control knobs are positioned closely together, making adjustments to each one potentially cumbersome.
  • a microphone volume control knob would be a great addition.

I got the Fosi K5 Pro, but should you too?

“Hold on… If DAC is the answer, you’re home…”

The Fosi Audio K5 stands out as a commendable compact device, boasting versatility with its support for Coaxial, Optical, and USB-C inputs, allowing for effortless switching among them.

Although I typically don’t lean towards using Bass and Treble adjustments on Amplifiers, I found these features significantly enhance the audio quality, even for the most affordable headphones and IEMs.

It’s capable of driving headphones up to 300 Ohms, powering (mind you, DACs are also dependent on the sound signal, a cheap 50 USD headphones will sound significantly worse) all IEMs and headphones I was using.

The device comes with a microphone splitter, facilitating an easy connection for gaming headphones and effectively separating microphone audio from game audio, which enhances your sound experience while gaming even more.

While it may not deliver the musicality of higher-priced options, its value becomes very apparent when considering its cost.

I have minimal criticisms regarding the Fosi Audio K5 Pro Gaming DAC. The knobs on the front are positioned closely together, which requires a bit of attention to avoid accidentally adjusting the wrong one when making changes. However, I prefer this compact design to a larger unit that would take up more desk space. I’d also love to have a knob to control mic volume.

The sound quality it delivers is impressive, capable of elevating a good pair of headphones to great and a great pair is pretty awesome. However, its sound signature tends to be on the clinical side, characterized by a bright and somewhat hard-edged tone, rather than a warm output. It doesn’t match the dynamic or musical depth of higher-priced devices, but considering its affordability, such a critique seems overly stringent.

The ability of the Fosi Audio K5 Pro to enhance the performance of every budget headphone I tested to a level that left me more than satisfied with the listening experience is commendable. My delayed review, due to the sheer enjoyment of using this device, speaks volumes of its quality.

After finally going after my friends’ advice — I can see there’s no turning back for me now as I will stick to using DACs from now on, both for gaming and music listening. I’m head over hill in DACs.


  • How does the Fosi K5 Pro upgrade gaming audio? It processes audio signals more efficiently than standard sound cards, reducing latency and enhancing sound detail, crucial for gaming.
  • Compatibility with headphones? Yes, it supports headphones ranging from 16 to 300 Ω, catering to a broad spectrum of users.
  • Unique features of the Fosi K5 Pro? Integrates DAC and amplifier, offering better sound quality, versatility, and the convenience of portable design.
  • Ease of setup? It is user-friendly, requiring no special drivers, and supports plug-and-play functionality.
  • Smartphone connectivity? Absolutely, it’s compatible with various smartphones for an enhanced mobile audio experience.
  • Importance of a DAC? A DAC is vital for converting digital audio files to analog, providing a purer and more authentic sound experience.

👊And if you are ready to elevate your sound, use the code QUAKEWORLD at checkout to claim your small % discount!👊

No enemy will catch off-guard now

If you don’t like it, it’s fine, you can always use fresh links to the Direct link to Mechkeys site I got it from.


And remember, this is just one gamer’s point of view — no sponsorships, no ads, just straight talk from someone who’s been in the QuakeWorld trenches. This was my own opinion and the manufacturer didn’t influcence me in any way. Your mileage may vary, so take my words as a starting point, not gospel. Happy gaming!



Damian Cooper

+25 years of gaming exp | Gaming Peripheral Reviewer | Mice | Mousepads | Keyboards | IEMS I DACs I Monitors I FPS Gaming