HiBy FC4 USB DAC/AMP Dongle Review 




HiBy was established in 2011 and is specialized in research, development and sales of Hi-Fi grade portable audio products such like DAP’s, USB & BT DAC/AMP’s and earphones. HiBy has also an experienced software team that has developed HiBy OS which is also one of the most widely used professional portable audio Operating Systems (OS) on the market.

The motto of the compamny is “MAKE MUSIC MORE MUSICAL”.

The HiBy FC4 that I will now review for you is the latest USB DAC/Amplifier Dongle of the company that utilizes an ES9218PC Dual DAC design and both 3.5mm Single Ended and 4.4mm Balanced outputs. Moreover, it offers some interesting features such like a FPGA Based Dual Independent Crystal Oscillator Re-Clocking, PCM up top 768kHz & Native DSD256 support, Hardware Volume Controls + RGB Status Indicator, MQA up to 8x unfold and many more.






I would like to thank HiBy for providing me the FC4 USB DAC/Amplifier as review sample. I am not affiliated with HiBy beyond this review and these words reflect my true and unaltered, opinions about the product.



Price & Availability:

The actual price fro the HiBy FC4 USB DAC/Amplifier is 89.00 US$. More information’s can be found under the link bellow;




Package and Accessories:

The HiBy FC4 came inside a relative small and compact sized square shaped cardboard box in black color that features product related brandings on its surface.


The box contains the following items/accessories;

  • 1 x HiBy FC4 USB DAC/Amplifier
  • 1 x Type-C to Type-C interconnect Cable
  • 1 x USB Type A to Type C interconnect Cable
  • 1 x Print Material (User manual / Warranty Card/ Certificate)





Design & Build Quality:

HiBy FC4 is a solid looking product with a modern industrial deign language, which has a rectangular shape with rounded corners that offers a nice grip when hold in your hands. The device has an All-Metal Body with dimensions of 65.3*22.1*11.9 mm that weights only 21.7 grams. On the top of the USB DAC/Amplifier dongle is the HiBy FC4 branding in yellow color.

Here is also a multicolor RGB status indicator that lights up in different color depending of the actual file format/status.

  • Green: MQA
  • Blue: MQA Studio
  • Magenta: MQA Rendering
  • Yellow: ≤48k
  • Aqua: 64k-192k
  • Orange: 352.8k or above
  • White: DSD Red: Paused

At the bottom of the HiBy FC4 are the 3.5mm Single Ended and 4.4mm Balanced headphone outputs. The 3.5mm Single Ended output supports headsets with CTIA-spec TRRS Standard.

On the rear side of the device are two fixing screws and the Motto of the company that is “MAKE MUSIC MORE MUSICAL”.

The left surface of the FC4 is equipped with a 30-step physical hardware volume button, which is a nice addition that I prefer over a digital volume control.

On the top of the FC4 is the USB Type-C digital input interface of the device in order to connect it with your Phone, Tablet or PC.

The overall build quality of the HiBy FC4 is rock solid same like all other products of the company that I have reviewed in the past.





Technical Specifications:

  • Model                         : HiBy FC4
  • DAC                            : 2 x ES9218
  • Analog Outputs          : 3.5mm Single Ended / 4.4mm Balanced
  • Digital Inputs              : USB Type-C Interface
  • Output Power             : 1.9Vrms @ 32Ω 3.5mm SE / 3.3Vrms @ 32Ω 4.4mm Balanced
  • THD+N                       : 0.0008%@ @ 32Ω 3.5mm SE / 0.0006% @ 32Ω 4.4mm Balanced
  • Noise                          : 1.7μVrms @ 32Ω 3.5mm SE / 3.3Vrms @ 32Ω 4.4mm Balanced
  • SNR                           : 120dB @ 32Ω 3.5mm SE / 123dB @ 32Ω 4.4mm Balanced
  • Dynamic Range          : 120dB @ 32Ω 3.5mm SE / 123dB @ 32Ω 4.4mm Balanced
  • Crosstalk Rejection    : 72dB @ 32Ω 3.5mm SE / 98dB @ 32Ω 4.4mm Balanced
  • Frequency Response : 20-90 kHz 3.5mm / 4.4mm Balanced
  • Supported Formats    : PCM up to 768kHz/32bit, up to DSD256 native
  • Deice Dimensions      : 65.3*22.1*11.9 mm (without cable)
  • Weight                        : 21.7grams (without cable)






Hardware & Software Features:

The HiBy FC4 is a pretty small ultra compact USB DAC/Amplifier dongle that offers some interesting Hardware & Software features such like 2 x ESS Technology’s 9218PC Digital to Analog Converter, Dual Independent Crystal Oscillators and HiByMusic App support.


A) DAC, AMP & Independent Crystal Oscillators:

The HiBy FC4 features ESS Technology’s latest power efficient ES9218PC Digital to Analog Converter (DAC) Chip for mobile devices that offers some nice specs such like a Signal to Noise Ration (SNR) of 120dB @32ohm and a Total Harmonic Distortion (THD+N) of about 0.0008% over the 3.5mm Single Ended output and a even better result of 0.0006% @ 32ohm over its 4.4mm Balanced (TRRRS) output interface.

The build-in amplifier offers a decent level of output power with up to 1.9Vrms @ 32Ω over the 3.5mm Single Ended and 3.3Vrms @ 32Ω over the 4.4mm Balanced analog output, which is quite impressive for such a small device.

The FC4 features also FPGA-based dual (45.158MHz and 49.152MHz) independent crystal oscillators in order to effectively lower the jitter and to provide the whole audio system a high precision, low jitter clock source.



B) Hissing:

The HiBy FC4 offers a very clean output over both the 3.5mm Single Ended and 4.4mm Balanced outputs, when I have tested the device with sensitive IEM’s such like the Campfire Audio ARA. The clean/dark output makes it possible to concentrate to the micro details that are reproduced in a pretty good manner for a USB DAC/Amplifier dongle at this price level.


C) Supported Platforms & Formats:

The HiBy FC4 is a very easy to use USB DAC/Amplifier that offers a driver free plug-and-play function. Supported are devices with Android OS, iOS, Mac OS and Windows 10 Computers.

The FC4 supports file formats up to PCM 768 kHz/32bit and Native DSD support up to DSD256.


D) HiByMusic app:

The FC4 is supported by the HiByMusic app, which has a USB exclusive mode that offers access to some interesting features such like bitperfect audio output over your smartphone’s or Gain Control of the integrated Amplifier section of the device.





Equipments used for this review:

  • DAC/AMP’s                           : HiBy FC4, Lotoo PAW S1
  • Sources                                 : Samsung Galaxy Note10 Plus, Asus TUF FX505DU
  • Headphones & IEM’s           : Meze Audio ADVAR, Moondrop Variations, FiiO FD7






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)
  • 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.B. King – Riding With The King (Tidal Hi-Fi)
  • Dave Gahan – Kingdom (Tidal Hi-Fi)
  • U2 – Sunday Bloody Sunday (Flac 16bit/44.1kHz)
  • Bro Safari, UFO! – Drama (Deezer HiFi)
  • Armin Van Buuren – Vini Vici (Flac 16bit/44.1kHz)
  • Really Slow Motion – Deadwood (Deezer HiFi)
  • Massive Attack – Angel (Flac 24bit/48kHz)
  • Jo Blankenburg – Meraki (Spotify)
  • Lorde – Royal (Flac 24bit/48kHz)
  • Toutant – Rebirth (Deezer HiFi)
  • Gogo Penguin – Raven (Flac 24bit/192kHz)
  • Portishead – It Could Be Sweet (Spotify)
  • No Doubt – Hella Good (Flac 24bit/48kHz)
  • 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)s
  • Liquid Tension Experiment 2 – Acid Rain (Spotify)
  • Yosi Horikawa – Bubbles (Spotify)








The Sound:

The HiBy FC4 is pretty powerful USB DAC/Amplifier Dongle that has a mildly warm tonality and overall smooth presentation. The lows of the FC4 reproduced in a dynamic, tight and surprisingly controlled manner. The midrange has a fairly balanced tuning that offers a good linearity fro the lower midrange towards the upper midrange area. The treble range on the other hand has a pretty smooth and controlled character that shows a moderated sense of extension.


This review has been written after a burn-in period of 50 Hours. I have used the stock short profile USB Type-C to USB Type-C cable that came inside the box of the FC4 and have paired the device mainly with my Samsung Galaxy Note10+ & Asus TUF FX505DU. My sound impressions below are based on my pairings with the Meze Audio ADVAR, Tin HiFi P1 MAX and Moondrop Variations IEM’s.


Bass / Midrange / Treble / Soundstage

The HiBy FC4 shows a pretty comfortable and pleasant to listen to subbass presentation with a slightly hint of warmness. It was able produce a decent level of subbass depth and rumble, especially when paired with IEM’s like the FiiO FD7 or Moondrop Variations. The subbass rumble in songs like Lorde’s “Royals”, Massive Attack’s “Angel” and Photek’s “The Hidden Camera” was quite satisfying.

The midbass region on the other hand sounds punchy rather than boomy and doesn’t show any remarkable negative situations like a midbass hump or muddiness that overflows to other frequency areas. Midbass character is successful with almost any type of genre and shows for example, an impressive level of authority and quickness while listen to drum intros with the Meze ADVAR in songs like Michael Jackson’s “Billie Jean”, No Doubt’s “Hella Good” and Opeth’s “Windowpane”. Other instruments such like bass and electro guitars are reproduced with an excellent grade of body and realism that I didn’t expected from such a small and well-priced DAC/AMP dongle.

The HiBy FC4 shows a relative close to neutral midrange presentation with a slightly amount of coloration that is not overdone. The level of clarity/transparency and airiness is above average, while the grade of resolution fulfils my expectation form a product at this price level.

Both male and female voices are reproduced in a fairly natural and realistic manner, which is one of the remarkable highlights that the FC4 offers. Female vocals are shown in general with a small amount of coloration, and do sound silky smooth and intimate thanks to the well-adjusted upper midrange response. There are no negative situations such as sibilance and or harshness, and I really enjoyed the female vocal presentation of the FC4 especially when paired with some of my favourite single Dynamic Driver IEM’s like the Meze Audio ADVAR and FiiO FD7. Male voices on the other hand such like Sting, Elton John, David Bowie and Isaac Hayes do sound relative realistic and emotional, while I would wish a tad more depth and body in the lower midrange area.

When it comes to the instrument presentation of the HiBy FC4, I can say that they are shown in general in a moderately warm, buttery smooth and fairly natural character, along with a good amount of detail retrieval, especially for such a well-priced audio gear. Instruments like pianos and violins do sound mildly bright yet controlled, while a contrabass is reproduced in a pretty realistic and natural manner.

The treble range of the HiBy FC4 has a mildly bright and pretty close to neutral tonality. The general presentation of this area can be described as smooth, relative airy and fatigue-free. I quite enjoyed the gentle and buttery smooth treble tuning of the FC4, while it would wish a bit more presence and brilliance in this area. The transitions from the upper midrange towards the lower treble region are quite controlled in moments when instruments are played with higher level of distortion.

Percussion instruments like snare drums and cymbals in genres like metal music do sound quite crisp and lively when paired with IEM’s such like the Moondrop Variations and Meze Audio ADVAR. Other instruments such like a hi-hat is fairly pronounced and countable, while crash cymbals are shown with a fairly quick and controlled decay.

The HiBy FC4 shows a sufficient performance in terms of separation and placement of instruments and vocals. The soundstage is not super expansive but the sense of depth and wideness is pretty good for such a reasonable priced USB DAC/Amplifier dongle.






HiBy FC4 versus Lotoo PAW S1:

The Lotoo PAW S1 is one of my favorite USB DAC/Amplifier dongles both in terms of hardware, design and musicality. The FC4 and PAW S1 are pretty similar when it comes to the dimension (PAW S1 66*22*13mm vs 65.3*22.1*11.9mm FC4), while the FC4 is a bit slimmer.

Both do come with 3.5mm SE & 4.4mm Balanced outputs and do have physical hardware buttons. The Lotoo PAW S1 offers a small OLED screen to access gain and other features, while the FC4 has no screen but the HiBy Music App. The PAW S1 offers up to 120mW @32ohm of output power over the 4.4mm balanced output, while the FC4 is much more powerful with 320mW @32 ohm.

The HiBy supports 32bit/768kHz PCM decoding and Native DSD support up to DSD256, while the Lotoo PAW S1 is limited to 32bit/384kHz PCM decoding and Native DSD up to DSD128.

When it comes to the sound, I can say that the Lotoo PAW S1 is the device with the warmer tonality and higher sense of general frequency coloration. The PAW S1 gives a more dynamic/energetic impression, but feels also a bit uncontrolled in direct comparison to the HiBy FC4 that offers a more balanced, natural and relaxed sound profile that is closer to neutral.

The subbass of region of the PAW S1 is slightly more pronounced, which shows a higher sense of depth and rumble. The HiBy FC4 sounds more linear and controlled in this area, while both devices do offer a similar performance when it comes to clarity and decay. The midbass region of the FC4 shows less coloration and offers a slightly better sense of transparency and resolution. Both the FC4 and the PAW S1 do offer a fairly similar performance in terms of layering in this area.

The midrange of the Lotoo PAW S1 has a warmer tonality and shows a more forward oriented and energetic presentation. The HiBy FC4 on the other hand has a more balanced, spacious and airy midrange atmosphere. The lower midrange of the FC4 is slightly less pronounced and shows less body and depth compared to the PAW S1 when I do listen to male vocals and instruments such like an acoustic guitar or to organs. The upper midrange of the PAW S1 is more energetic and slight more detailed compared to the FC4, which offers a better sense of control and naturalness when I do listen to female voices or to instruments such like a flute or piano.

The HiBy FC4 shows a smoother and more balanced treble tuning that is ideal for longer listening periods. The Lotoo PAW S1 on the other hand shows a higher grade of colorations (brighter tonality) both in the lower and upper treble register. The PAW S1 sounds energetic and offers a higher sense of resolution an extension, while it is prone for sibilance and over sharpness especially when I do listen to soprano vocals or to cymbals and snare drums especially in metal music.

The HiBy FC4 has the upper hand when it comes to the separation of instruments thanks to its more specious and airy soundstage atmosphere that offers a better sense of depth and wideness.





The HiBy FC4 is a compact USB DAC/Amplifier in form of a dongle that offers some interesting Hardware & Software features. It comes with 2x ESS 9218PC DAC’s, Dual Independent Crystal Oscillators and offers HiByMusic App support. But what really surprised me was its sounds character and overall performance in this area, which is stands out with a mature, versatile and balanced tuning that shows pretty good synergy with almost any earphone that I have listen with this device.




Pros and Cons: 

  • + Natural & Balanced Sound Profile
  • + Decent Level of Control and Resolution
  • + Powerful Output (320mW @ 32ohm)
  • + Hardware Volume Button
  • + Great Value for your Money
  • – Resolution and Extesion of the Treble Region
  • – Lightning Cable Sold Separately
  • – No Protective Case



Thank you for the Read!




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2 Responses

  1. name says:

    Fix that DSD246 🙂

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