Fosi Audio K5 Pro Review




Fosi Audio K5 Pro DAC/AMP Review




Fosi Audio is a Chinese company is specialized reliable and easy-to-use Budged HiFi solutions such like DAC’s, Preamplifiers, Bluetooth Amplifiers and Speakers. The K5 Pro that I will now reviews for you are the latest Gaming DAC & Headphone Amplifier of the company that is suitable for the use with Active Speakers, PC’s, MAC computers, Smartphone’s and Tablets or with Gaming devices such like a PS5 and Nintendo Switch.

The K5 Pro features Texas Instruments NE5532 Op-Amp chip and offers digital connectivity over USB Type-C, Optical and Coaxial inputs and converts it to analog audio signals over the 3.5mm AUX and RCA outputs. Moreover, it is equipped with a MIC (Microphone) input and has independent hardware volume, bass and treble controls.



I would like to thank Fosi Audio for providing me the K5 Pro as review sample. I am not affiliated with Fosi Audio beyond this review and these words reflect my true and unaltered, opinions about the product.



Price & Availability:

The actual price of the Fosi Audio K5 Pro is about 75.99 US$. More information’s can be found under the link below;



Package & Accessories:

The Fosi Audio K5 Pro came in a rectangular box with some brandings and their motto “HiFi Made Fun” on the top.


Inside the box of the Fosi Audio K5 Pro are the following items:

  • 1 x Fosi Audio K5 Pro DAC & Amplifier
  • 1 x USB Type-C Cable
  • 1 x Headset Microphone Two-in-one Adapter Cable
  • 1 x Optical Cable
  • 1 x User Manual


Design & Build Quality:

The Fosi Audio K5 Pro is a pretty small yet powerful desktop type Gaming & HiFi DAC/Amplifier that shows a robust build quality with its metal housing. The device has dimension of approx 112x95x30mm and weights about 251 grams.

The surface of the metal housing has a grey finish and the sides do have a curved shape.

On the front of the Fosi Audio K5 Pro is the control panel with USB, Optical and Coaxial LED status indicators and the some brandings on the top. Here is the 3.5mm headphone output that doubles as line out port and the 3.5mm MIC (Microphone) input.

The Bass, Treble and Volume knobs are quite precise, while they do feel a bit too close to each other. I really like the ability to fine adjust the bass and treble manually, which is in my opinion a pretty nice feature. However, both the bass and treble knob are in most cases useful if you turn them till 3 o’clock, while anything further starts to create an unwanted distortion.

BTW, please not that the 12 o’clock position is the default setting for both the Bass and the Treble knob. The volume knob doubles as a power button to turn on the device by pressing it for approx 2 seconds. What I do miss and would really wish on the K5 Pro could be a gain adjustment switch/knob, which could be pretty useful while listen to sensitive In-Ear Monitors.

At the rear side of the device are two screws, the USB Type-C, Optical and Coaxial inputs and the RCA Left/Right outputs. The USB Type-C port works as both Power and Digital input interfaces.

At the bottom of the device are fours stands made from some sort of rubber material.

All in all, the build quality of the device is pretty good and fulfills the expectations from a product at this price level.





Technical Specifications:

  • Model                         : K5 Pro
  • DAC                           : unknown
  • Compatibility              : PC, Mac, PS5, PS4, PS4 Pro, Nintendo Switch, Smartphone’s
  • Amplifier                     : Texas Instruments NE5532 OP-AMP
  • Output Power             : 1000mw@16Ω, 500mw@32Ω, 80mw@300Ω
  • THD                            : ≤0.003%
  • SNR                           : ≥ 110dB
  • USB In/Out                 : USB Type-C (Data/USB DAC/USB Audio)
  • Digital Inputs               : USB Type-C, Coaxial, Optical
  • Analog Inputs             : 3.5mm Line-In, 3.5mm MIC
  • Analog Outputs          : 3.5mm Single Ended, RCA
  • Sampling Rates          : USB 24 bit/96 kHz / Coaxial/Optical Up to 24 bit/192 kHz
  • Impedance                 : Headphones between 16-300 Ω
  • Power Input                : DC 5V via USB-C
  • Dimensions                : 112x95x30mm
  • Weight                        : 251grams



Amplification & Audio Parameters:

The Fosi Audio K5 Pro is equipped with 3.5mm Single Ended headphone output that shows a THD      (Total Harmonic Distortion) of approx ≤0.003% and a SNR (Signal to Noise Ratio) that is at ≥110dB, which are values that are pretty good for such a well priced device.

The K5 Pro is a pretty powerful DAC/Amplifier thanks to the use of Texas Instruments NE5532 OP-AMP chip, which is able do produce 1000mW@16Ω, 500mw@32Ω and up to 80mw@300Ω.

The device has a relative audible background noise if you listen to it with an In-Ear Monitor. Headphones on the other hand seem to be more tolerable, especially harder to driver planar headphones such like the HiFiMAN Edition XS.


DAC Function & Sampling Rates:

The Fosi Audio K5 Pro is compatible with a wide variety of devices and offers a easy to use “plug and play” functionality for PC’s (Windows 10 and above), MAC Computers, Android Smartphone’s and Tablets. The K5 Pro works also with Gaming devices such like a PS5 and Nintendo Switch.

The Fosi Audio K5 Pro supports sampling rates up to 24 bit/96 kHz over the USB Type-C input, while the Coaxial & Optical outputs do support sapling rates up to 24 bit/192 kHz.



Equipment’s used for this review:

  • Sources                     : Fosi K5 Pro, ASUS TUF FX504GD, Samsung Galaxy S22 Ultra
  • IEM’s                          : 7HZ Timeless AE, BQEYZ Winter
  • Headphones             : HiFiMAN Edition XS, Moondrop Void



Albums & tracks used for this review:

  • Adele – My Little Love (Spotify)
  • Randy Crawford – On Day I Will Fly Away (Flac 16bit/44.1kHz)
  • Hayley Westenra – Odyssey Album (Dezzer HiFi)
  • Dionne Warwick – Walk On By (Flac 16bit/44.1kHz)
  • Sarah McLachlan – Angel (Flac 24bit/48kHz)
  • Sertap Erener – Aşk (Flac 16bit/44.1kHz)
  • Edith Piaf – Non Je Ne Regrette Rien (Flac 16bit/44.1kHz)
  • Diana Krall – So Wonderful (DSF)
  • Aretha Franklin – I Say A Little Payer (Flac 24bit/96kHz)
  • Sonya Yoncheva – (Giuseppe Verdi) II Trovatore, ActI (Flac 24bit/96kHz)
  • George Michael – Don’t Let the Sun Go Down on Me (Flac 24bit/192kHz)
  • David Bowie – Heroes (Flac 24bit/192kHz)
  • Elton John – Rocket Man ((Flac 24bit/96kHz)
  • Barry White – Just The Way You Are (Flac 24bit/48kHz)
  • Isaac Hayes – Walk On By (Flac 16bit/44.1kHz)
  • Sting – Englishman in New York – (Flac 24bit/48kHz)
  • Eric Clapton – Wonderful Tonight (Flac 24bit/96kHz)
  • B. King – Riding With The King (Tidal Hi-Fi)
  • Dave Gahan – Kingdom (Tidal Hi-Fi)
  • U2 – Sunday Bloody Sunday (Flac 16bit/44.1kHz)
  • Muse – Hysteria (Flac 24bit/96kHz)
  • Rush – YYZ (Flac 16bit/44.1kHz)
  • Red Hot Chili Peppers – Nobody Weird Like Me (Flac 24bit/48kHz)
  • Bro Safari, UFO! – Drama (Deezer HiFi)
  • Rok Nardin – Berserks (Spotify)
  • Bear McCreary – Valkyries “God of War OST” (Deezer HiFi)
  • Armin Van Buuren – Vini Vici (Flac 16bit/44.1kHz)
  • Daft Punk – Doin’ it Right (Flac 24bit/96kHz)
  • Jo Blankenburg – Meraki (Spotify)
  • Lorde – Royals (Flac 24bit/48kHz)
  • Massive Attack – Angel (Flac 24bit/48kHz)
  • Toutant – Rebirth (Deezer HiFi)
  • Gogo Penguin – Raven (Flac 24bit/192kHz)
  • Gogo Penguin – Murmuration (Flac 24bit/192kHz)
  • Alboran Trio’s – Cinque Lunghissimi Minuti (Flac 16bit/44.1kHz)
  • Portishead – It Could Be Sweet (Spotify)
  • Max Richter – On the Nature of Daylight (Flac 24bit/96kHz)
  • Charly Antolini – Duwadjuwandadu (Flac 24bit/192kHz)
  • Ferit Odman – Look, Stop & Listen (Flac 24bit/192kHz)
  • Chopin – Nocturn No. 20 In C-Sharp Minor (Flac 16bit/44.1kHz)
  • Fazıl Say – Nazım Oratoryosu (Live) (Flac 16bit/44.1kHz)
  • Vivaldi – Le QuarttroStagioni “The Four Season” (Deezer HiFi)
  • Otto Liebert& Luna Negra – The River (Flac 24bit/192kHz)
  • Lunatic Soul – The Passage (Flac 16bit/44.1kHz)
  • Deftones – My Own Summer (Shove it) (Flac 16bit/44.1kHz)
  • Metallica – Sad but True (Flac 24bit/96kHz)
  • Opeth – Windowpane (Flac 16bit/44.1kHz)
  • Megadeth – Sweating Bullets (Tidal Hi-Fi)
  • Rush’s – Leave That Thing Alone (Flac 16bit/44.1kHz)
  • Slayer – Angel of Death (Spotify)
  • Liquid Tension Experiment 2 – Acid Rain (Spotify)
  • Yosi Horikawa – Bubbles (Spotify)




The Sound:

Please note that this review has been written after a burn-in period of about 70 hours. My sound experience below are based over the 3.5mm Headphone output paired with In-Ear Monitors like the BQEYZ Winter and 7HZ Timeless AE and headphones like the Moondrop Void and HiFiMAN Edition XS. The Bass and Treble knobs have been set to 12 o’clock, which are the default settings of the K5 Pro.

Bass / Midrange / Treble / Soundstage & Imaging:

The Fosi Audio K5 Pro has an efficient level of subbass depth and extension, while this area has a relative smooth and slightly warmish tonality. It is not very dominant and shows an average amount and emphasis in the default setting. The depth and rumble of this area can be easily increased if you turn the bass knob towards 3 o’clock, while it starts to create unwanted distortions especially with In-Ear Monitors if you increase it a bit further. The midbass region is produced in general with good amount of body and impact, while the level of resolution and clarity fully meets my expectation from a DAC/Amplifier at this price range.

The midrange of the Fosi Audio K5 Pro has a tad warmer than neutral tonality and shows fairly soft and smooth in its presentation. It offers a good level of resolution for a product at this price level when I do listen to a wide variety of genres. The midrange is not too laid back or to upfront. Both vocals and instrument are reproduced with an adequate grade of depth and fullness in the lower midrange area with the default knob setting (12 o’clock). However, you can easily increase the sense of body of this region when you turn the knob till 2 o’clock without to make it sound unnatural or muddy.

The Fosi Audio K5 Pro has a close to natural tonality upper midrange tonality that shows a better grade of clarity and detail retrieval compared to the lower midrange area, since female vocals have are reproduced with a higher sense of transparency and resolution. Instruments like guitars are tad warmer than neutral, while pianos are bright but fairly controlled in the upper midrange register. The upper midrange sounds in general quite transparent and spacious, while the transitions towards the lower treble area are in fairly controlled.

The treble range on the other hand is fairly pronounced and energetic, while the general tonality is moderately bright. The level of airiness that is created in the treble range is on an adequate level. The lower treble range of the Fosi Audio K5 Pro sounds a tad more highlighted and detailed compared to the upper treble region. Instruments like crash cymbals are shown with average intensity sharpness, while the hits are in general fairly controlled.

When it comes to the soundstage of the K5 Pro, I can say that it offers a sufficient sense of depth and wideness, where instruments and vocals are placed in a relative accurate and realistic manner, especially with respect to the price of this small Desktop type of DAC/Amplifier.



The Fosi Audio K5 Pro is a pretty small and easy-to-use DAC/Amplifier solution with a good built quality, wide variety of in- & output options and an above average sound performance that will satisfy both Gamers and Audiophiles with a limited budget. The microphone input and the option to fine adjust the Bass and Treble intensity are some remarkable additions.



Pros & Cons:

  • + Above Average Sound Performance for its price segment
  • + Above Average Sound Performance for its price segment
  • + Small & Lightweight
  • + Wide Variety of In- & Output Options
  • + Bass & Treble Knob
  • + Price Performance Ratio


  • – Slightly amount of white noise at higher volumes (audible with sensitive IEM’s)
  • – Bass & Treble Knob creates distortion when you crank it to much
  • – Nothing remarkable for such a reasonable price


Thank you for the Read!



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