Hidizs S9Pro


100+ Head-Fier
HIDIZS S9 PRO: Pocket-Sized Hi-Fidelity Tool
Pros: ● Small, light pocketable size USB DAC/Amp dongle.

● LED indicator for detecting sample rate of an audio file format.

● Clean and neutral sounding with impeccable almost uncoloured tuning.

● Up to par bass response.

● Sufficiently lush and balanced texture midrange

● Shimmering, detailed and airy treble.

● Detachable connector.

● Powerful output on both balanced and unbalanced headphone jacks with almost desktop-grade performance.

● Quite impressive on handling build-up heat on such a small device.

● Can even process a DSD256 file format and even DSD512, what a processing little beast.
Cons: ▽ No hardware volume key button.

▽ An absence of built-in battery on which turn this dongle device into a parasitical power-craving set. (But in a silver lining, it deliver an excellent sound quality)

▽ Sorry MQA lovers, MQA unfolding is not supported on this device.

"Necessity is the mother of innovation"

The removal of the headphone jack in the smartphones was supposedly the end of the analogue technology that traces back to the late 19th century but the 3.5mm was standardised only in the 1970s with the introduction of Sony Walkman. And 3.5mm SE becomes the staple connector to all multimedia devices including smartphones. With this so-called "courage" path of that company, a move initiated the removal of the beloved analogue jack of their phone started this movement and most companies follow this suit (Even one company making a mockery out of it but afterwards they follow suit as it was a "necessity" for the improvement of their product to be more competitive in the market).

The removal of headphone jacks seems to be a blessing to some enterprising audio companies. These audio companies decided to offer a working solution on this issue of scarcity, a Hi-Fi DAC/amp in a USB pen drive form factor. I was already aware of the existence of these contraptions since 2017 and Audioquest Dragonfly Black was the first device that I've encountered but I digress.


Speaking of enterprising audio companies, Hidizs is one of the companies that were very active and constantly projecting their presence in the current audio market. Hidizs was established in 2009 and it was founded by Mr. Tamson who happens to be a member of a local underground rock band during his college days in his home country and also an audio enthusiast who has a dedication of creating Hi-fi portable gadgets like DAPs and other audio accessories. Along with his fellow colleagues in the audio community scene and some of them have extensive knowledge and experience in audio fidelity engineering, they put up their own dedicated Research and Development in their own company to provide a better product at an affordable price. The Hidisz Sonata HD was the first product that I've encountered from them and their AP80s are among the most popular items for budding portable audiophiliacs.

Let me remind you that this is my first product review on a USB DAC/Amp dongle and I try to simplify my review to be understandable to all readers and sufficiently detailed despite my limited knowledge regarding this subject.


Hidisz S9 Pro is a USB DAC/Amp dongle, this is a flagship model of their USB dongle line-up. It's a variant of the Hidisz S9 with some improvements in power output.

It has a small rectangular form factor which has similar sizes with some USB pen drives. The rectangular-shape casing is made of CNC milled aluminium alloy with a glass-like panel of its surface and it's quite very light and somehow durable, able to withstand a few accidental falls. My colour variant of S9 Pro has a silver-finished coating that looks really attractive and of high quality.


Both of side ends have different kinds of port, a USB type-C socket and its opposite side was a pair of headphone jacks of different output, one is 2.5mm balanced ( I actually wish for 4.4mm but due to the constraints of small sizes its impossible) and a unbalanced 3.5mm single-ended termination.

The 3.5mm output was rated up to 100mW at 32 ohms (2 Vrms) and up to 200mW at 32 ohms (4 Vrms) which is quite powerful already to most IEMs out there and even to some power hungry cans (a fellow audio enthusiast who happens to be my online mate claims that it can even drive a Fostex T40RP III which have those power demanding planar magnetic transducers). It still wonders to me how Hidizs managed to make it work despite its minuscule size.


It is also noted the S9 Pro has colour-coded LED light for sample rate and bit depth.

Here are some of the colour indicator:

GREEN - PCM 16-32bit /44.1-96 KHz

BLUE - PCM 24-32bit/192 KHz

RED - PCM 24-32bit/384 KHz

WHITE - PCM 24-32bit/768 KHz

YELLOW - DSD 64-128

VIOLET - DSD 256-512

I have some types of audio file formats in my digital collection, most of them are of lossless format. I've also tested them in the Hiby Player Music app in USB exclusive mode.

Inside of S9 PRO chassis, Hidisz implemented a high performance, flagship-grade ESS DAC ES9038Q2M which I'm very familiar with as it is also implemented on my F.Audio DAP, and this type of ESS DAC is also found on some desktop DAC/Amps like from McIntosh, Burson and Topping. ES9308Q2M is a reference DAC specifically for audiophile-grade portable and desktop devices like DAPs, A/V receivers, mixer and pre-amp consoles. It is also noted that the ES9038Q2M has a powerful Saber 9602 headphone amplifier to deliver the best possible audio volume. Looks like that I have a very strong relationship with the ESS as most of my LG phones and a lone DAP have ESS DACs on their internals so I consider myself as an ESS DAC enthusiast (just kidding).

Another thing to remember about S9 PRO that it doesn't have a built-in battery and to power it up, it siphons off on the battery power of the device sources and it is really quite a nasty, insatiable parasitical audio implement that devours a substantial amount of power if you play some tracks with a sample bitrate of 24bit/192 KHz PCMs to DSDs file formats. And also there is the absence of hardware volume key that you will use on your transport device's volume key buttons and even software of the app you are using. It should be also noted that this thing does really warm up after a few minutes of using it but not to the point that it is a hot iron-like heat.

As for its packaging and inclusions, S9 PRO was packed in a small-size black box and its inclusions are the following:

  • Hidisz S9 PRO USB Dongle
  • Type-C to USB-A adapter
  • Transparent USB dongle holder with cloth clip.
  • A thick Type-C to Type-C short cable with a silver colour insulated coating
  • Some paperworks such as instruction manuals, Q.C. card, a card discount voucher and serial number card.
  • A pair of Hi-Res audio logo sticker (to make hi-fi sound have added even more fidelity and resolution…just kidding)




If you are an iPhone user, the Lightning connector to USB-C is sold separately and it is available at the Hidisz Store.

Another helpful advice is if you put the Type-C connector, make sure that the one that you are inserting with has a Hidisz logo on its casing or else it won't work.

So I've only tested the S9 PRO to my Android smartphones and a macbook (connected it to a Type-C Thunderbolt slot) and all of them work flawlessly. It works on apps in Android OS such as UAPP (USB Audio Player PRO) and Hiby Music Player app.


In general sound quality of this item, Hidisz S9 PRO seems to have a balanced-neutral to reference-neutral sound signature (depends of the ear/head gear that you are using which should have at least a "neutral" type tuning either warmish-neutral to neutralish-bright) as it has an ample texture in all parts of frequency sound spectrum with just a tad of upper mid peaks and presence (some source-zealots will probably interpret it as a "Saber Glare")


S9 PRO has intended a very impressive bass response in both quality and quantity. It has this precise, articulate and has a good impact as it really stays very static within its frequency range without a hint of smudges that might spillover to other parts of the sound spectrum.

Sub bass is slightly a bit prominent in overall bass region for it has that rumble and reverberation that discernly feel it. Bass synthesizers on some Synth-pop tracks are well-outlined and crisp. Mid bass has an ample texture to give a sufficient note weight on bass guitars, bass kicks and bass-baritones. That density gives a resonant and weighty sound of a bass guitar that even plucking, slapping and strumming are clearly heard. Bass kicks have an enough pounding and sustaining sound thus double bass kicks of some complex metal tracks are executed in a meticulous way. Bass-Baritone vocals have an adequate guttural recital.


Certainly that it has an excellent linearity and almost flawless midrange quality with an exuberant, transparent and pristine within its character. Both male and female vocals exhibit an organic and life-like presentation. Male vocals are firm, broader and deep in all categories of vocal types. Female vocals sound very pleasant as it has this euphonic, mesmerising and soothing feel in contralto to mezzo-soprano voice while sopranos have this silky, shining with expansive spatial range and yet melodic.

Presentations of instruments are accurately reproduced especially on strings as it gives a crisp with well-defined overtones on guitar either rhythm and acoustic ones, a vibrant and lustrous sound of a violin on every bowstroke on its strings. Piano tones seem to have a lively, rich and eloquent sound. A brisk and dynamics on percussives like snare drums as it has that sharpness, precise and penetrating sound. And finally the woodwinds like saxophone and fife have that warm, lustrous and incisive in a higher note and brass instruments like trumpets and horns have this metallic, brilliant, blaring and austere in lower note register.


As I mentioned that S9 Pro has some reference-neutral characteristics, it has some emphasis on treble region that gives that analytical, dry and airy sound at the expense of being too lean but S9 Pro doesn't even sound lean and inadequate.

In fact, It has a substantial texture and definition in this particular part of the frequency range spectrum.

Treble has an almost spotless, lucidity, shimmer and crisp quality that defines its detail quality and tones of harmonics.

Cymbals strikes have that snap and elan as it has a glistening, metallic and a sizzle that has good extension towards the brilliance region with sparkle and air. Hi-hats appear to have that shorted buzzing and shrill which is its natural sound characteristic.


S9 PRO is very proficient in projecting its technical capabilities. It has a wide sound field that gives a sense of expanse within its headroom, excellent height reach and good depth value for the distance range between front to rear. With these impressive spatial proportion, It does give that immersive 3D-feel on how it give an accurate spatial cues on placement of instruments and vocal positioning, with a very specific and distinguished on layering forte on interpreting each distinct frequency and dynamic character along with significant separation of each element that even a very complex track like multi-instrumentals scores will absolutely play it effortlessly with no hint of congestion and chaotic sounding.

It is also adept at delivering a clear, well-detailed and resolving capabilities in a pitch black background sonic canvas. Harshness and grainy noise floor is practical absent on this one.



  • It has a bit larger chassis and more solid build with matte coating finish. It has a 3.5mm SE and USB Type-A port which is contrasting to a more modern features of S9 PRO like 2.5mm balanced and a type-C por but if you want to use it in smartphones specifically android, you need that proprietary adapter and USB OTG cable which is quite a hassle to set it up in my opinion.
  • It has a mild U-shaped sound signature and manifests a natural timbre but it is a bit softer in presentation and less detailed compared to S9 PRO. Bass is a unrefined and vague in presentation, Mids is in a neutral and transparent state and treble is even more even unpolish as it shows some coarseness, grainy and metallic due the boosted upper mids. Sample rate and bit depth of Dragonfly Black is somehow capped to 96 KHz PCM and doesn't even support native DSD capability but it can do MQA rendering.
  • Technical aspects on this one clearly shows its age, it is totally outclassed by the S9 Pro by a mile from staging to resolving capability. A few notable advantage of Dragonfly Black was it plug & play mode that it can be use to all music apps in Android and will act as a headphone amp while S9 Pro is more specific and limited as you can use only on few music apps like UAPP, Hiby Music Player app and Neutron app.

To conclude this review, USB Hifi Dongles like the Hidisz S9 Pro became an important and logical implement as the continuous abandonment of the venerable headphone jack by most smartphone companies seems to be an inevitable and it is indeed a future tool for mobile audio enthusiast who wants to experience a high fidelity musical experience that is portable and ease of use.

For sure that this USB Hifi dongle is quite voracious and glutton on sucking up some battery life on the device on which Hidizs S9 PRO is connected, but as for sound performance it is unequivocally deliver an almost-desktop grade DAC/Amps sound quality with a clean, accurate sound reproduction and brimming with good details and solid macrodynamics.

Will I ever recommend this one to some budding audiophiles? I will definitely endorse this one without batting headphone and hesitation.

HIDIZS S9 PRO is still available for purchase and if you are interested to purchase it, just click the link there below. You can also check out there the detailed specification of this product.

◆○ LINK ○◆

"Titillate the sounds of your guilty pleasure".



Some Tracks Tested: ( * = 16-bit FLAC, ** = 24-bit FLAC, *'* = MQA, '*' = DSD, *'= .WAV)

Alison Krauss -When You Say Nothing At All *

Jade Wiedlin - Blue Kiss**

Led Zeppelin - When The Levee Breaks **

Mountain - Mississippi Queen *

Queen - Killer Queen **

Guns N' Roses - Patience *'*

Eric Clapton - Tears in Heaven '*'

Sergio Mendes- Never Gonna Let You Go '*'

Pearl Jam - Daughter **

Roselia - Hidamari Rhodonite *

Assassin - Fight (To Stop The Tyranny)*

Celtic Frost- Visual Aggression *

New Order - Blue Monday *

The Corrs- What Can I do (unplugged version) *

Jimi Hendrix Experience - Voodoo Child *

The Madness- Buggy Trousers *

Metallica - Motorbreath **

Mariah Carey- Always Be My Baby *

Destiny's Child - Say My Name *

Malice Mizer- Au Revoir *

Mozart - Lacrimosa *

New York Philharmonic Orchestra - Dvorak- Symphony 9 " From the New World." *

Eva Cassidy - Fields of Gold (Sting cover)*

Michael Jackson - Give In To Me *

Exciter - Violence and Force *

Diana Krall - Stop This World **

Debbie Gibson - Foolish Beat *'*

The Sisters of Mercy – Lucretia My Reflection**

Suzanne Vega – Luka **

Lauren Christy – Steep *


I am not affiliated to HIDIZS nor receive monetary incentives and financial gains as they provide me a review unit for an exchange of factual and sincere feedback from yours truly.

Once again, I would like to thank EMMA LI for providing this review unit. I truly appreciate their generosity towards me and other reviewers.

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Headphoneus Supremus
Pros: Power vs size, clean output
Cons: A physical link is not the most convenient connection while walking
The Hidzs S9 Pro is an ultraportable amp/DAC adapter for smartphones and computers.
It uses ESS9038Q2M DAC chip, in order to support up to 32bit/768kHz (for PCM) and up to DSD512. It has two headphone outs: balanced (2.5mm) anmd single ended (3.5mm). It has a USB Type C input for connection.
The S9 Pro has a screwless aluminium body and a stylish LED indicator which lights up in different colors, depending on the sample rate of the music being played.
The Hidizs is really tiny: it measures 59 mm * 18 mm * 8mm , so it can be fit pretty much everywhere, and it only weighs 11 grams. In order to achieve such small footprint, it has no battery by itself, so it needs to be powered by the controlling device through its connection.
For its small size, the Hidizs S9 Pro is remarkably powerful, rated at 100mW@32Ω. In comparison, my older dongle (Tempotec HD Sonata Pro) was rated only 60mW@32Ω and was still much more powerful than the a Blackberry Keyone headphone out.

Hidizs S9 Pro


The Hidizs S9 Pro comes with a short USB-C to USB-C cable (for Android connectivity) and a USB-C to USB-A adapter (for PC), while a Lightning cable for connection with a iPhone is not included.
I could test the S9 Pro with my Windows 11 PC and Blackberry Keyone Android smartphone.
The provided USB-C to C cable is a bit of a weak link, as it was loose with my Blackberry USB Type C port.
Connecting the S9 Pro to the PC or phone is plug and play, and once the headphone is inserted in S9 Pro headphone jack, it’s ready to be recognized as the new audio output.
Not having a battery on its own, the Hidizs S9 Pro contributes draining the phone’s battery. How faster would depend on the capacity of the phone’s battery itself. On my Blackberry Keyone, for example, charge would last about 20% less.

Hidizs S9 Pro jack

Sound Quality

I have tested the Hidizs S9 Pro with my Etymotic ER49, Hidizs MS2 and Sennheiser Momentum over-ear.
With the external DAC, against the built-in headphone out of my PC and smartphone, the main advantages are the more impactful bass, higher definition and slightly wider soundstage, and slightly higher treble energy. Moreover, in passages where the phone would clip, with sustained bassy passages (e.g. in electronic music), where more current is required, especially with the more power demanding Sennheiser Momentum, such passages are effortless with the S9 Pro.
The increased soundstage is tied to both the cleaner output and the additional power, which can make impulse response a bit faster.
When increasing the volume, it grows linearly in all frequency departments. While many headphone jacks tend to attenuate treble slightly, probably for energy saving reasons, the S9 Pro does not, increasing the perception of additional treble detail with the increased volume, and maintaining a sensation of cleanness across the spectrum.

Over the Tempotec (although I don’t have it anymore, so I need to go by memory) the main difference is that the Tempotec simply sounded “louder” than the headphone jack, so I felt underwhelmed, while the S9 Pro has a more refined output, as described above.

The Hidizs S9 Pro noise floor is low enough for my IEMs (and even more so my Momentum), although it’s possible that some hiss might be picked up with super sensitive IEM (e.g. 119dB sensitivity).

Hidizs S9 Pro MS2

Bottom Line

Tnhe Hidizs S9 Pro is useful for people who need a high quality and both powerful headphone output, either because their smartphone doesn’t have one, or because they would like to improve the output power and cleanness of their device (being it a smartphone or PC). Finally, it’s a great choice for people who have a balanced headphone.
Having a neutral sound signature, it would pair well, tonally, with pretty much all kind of headphones; as such, it’s a definite upgrade over any smartphone/PC headphone jack, at the cost of connecting it as additional link between the device and the headphone itself.

Hidizs S9 Pro Momentum
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My Hidizs S9 Pro update: It's the same despite different cable combos and plugging-in my pair of BQEYZ KC2 into 3.5mm jacks on various phones phones compared to both the 3.5mm and 2.5 balanced outputs on the S9 Pro, but I think the KC2 is source sensitive and doesn't like whatever's coming out of the dongle DAC-AMP.

Basically I'm hearing background hissing static-y noise as songs/tracks fade out with the way the static noise fizzles out being different at the end of each track.

Hasn't happened on any of my other earbuds & IEMs when paired with the S9 Pro. Hopefully I can enjoy the KC2 with the Cayin RU6 I'm planning to get sometime soon.

P.S. I paired the BQEYZ KC2 with my pair of Fiio UTWS 3 tonight and the end-of-track hissing static was absent so that's good. Apparently my pair of BGVP Zero also has this problem with the Hidizs S9 Pro so I'll update you guys here again if I find more cases like this.


100+ Head-Fier
Small but powerful
Pros: Power, size, portability, detail, clenaliness,
Cons: Power consumption, a little hot in the treble, may cause fatigue,

Let me start out by saying that I am not someone who has tested a lot of dongle style audio devices. I have a few Apple Dongle DACs, and have tried a few of the Creative Labs and similar solutions for laptops quite some time ago, but that is about it. But let’s face it, dongles are in fashion at the moment, with releases from all kinds of companies and at all kinds of prices, from the Apple option at less than 10€ (or even cheaper from some other random brands), all the way up to over 300€ or maybe even more.

I am actually a happy user of the Apple Dongle, it has proven to be of very good quality for its price (which is why I have ended up with multiple units) but there are a few situations in which the tiny device just can’t cut it. This is mainly with over ear headphones, which I rarely use away from my desktop devices anyway, but there are also some IEMs that benefit from having a little more power, especially if we consider the fact that the EU version of the Apple Dongle is only half as powerful as the US version.

So, my review of the Hidizs S9 Pro is really only going to be my opinions on this little portable device in my intended use scenario, without much comparison to anything similar. If you want detailed specs on the S9 Pro, with a full set of measurements etc, along with a very good review (in my opinion), you can check out the review by CqTek which is 2 reviews below this one or available on his site here: https://hiendportable.com/hidizs-s9-pro-english-review/

My use case…

My main reason for looking for something like the S9 Pro is to have a very transportable device that I can keep in my bag (ok, man purse) and give me something that has a similar sound signature to the Atom and THX set ups that I (usually) use for detailed listening and comparisons when reviewing.

Without going into sound preferences, basically I just wanted something as clean and detailed as possible, while being as small and compact as possible. I also wanted something that I could plug into my DAP to be able to have the same sound reference without being tied to my phone or tablet, more on that in a moment.

As I said, I don’t have much experience with dongles so I spent some time checking out reviews of all kinds of solutions. I don’t think that there was a single one that had all positive reviews, which is to be expected, and some of the most praised were ones that had some kind of “house sound”. Again, my search was for something that didn’t really have a sound, just pure old gain, in order to evaluate IEMs and not necessarily relax and listen.

The S9 Pro seemed to fit this description along with a few other contenders and was actually the cheapest option out of those that were easily available here.

Anyway, I think that is enough random chat, so on to the actual product.



The presentation of the S9 Pro is nothing spectacular. It arrives in a simple black box with some text on it, inside which we find the dongle in a foam cutout. Underneath the top layer of foam we get the included accessories, consisting of a user manual, a transparent clip, a short USB-C to USB-C cable and a USC-C to USB A adapter.

All the necessary bits are there and it is well packed, but again, it’s not really anything exciting for the price.

Build and aesthetics…

The S9 Pro is smaller than I expected it to be, which is good. After seeing photos online, I expected it to be larger than it actually is, which is still bigger than something like the Apple Dongle but is small enough to store in an IEM case quite easily.

The build of the actual unit is ok. Again, I wouldn’t go crazy and say that it is great, although there is nothing really wrong with it. The aluminium frame is nice but the glass covers on each side, which actually feel like perspex more than something like gorilla glass, do move and creak quite a bit when pressed with any kind of moderate force. Really there is no reason to actually press them with any kind of force, so I guess this is just me being picky, but it doesn’t exactly scream “high quality build”.

The included cable is also ok. It seems to be well made but the length is not quite right for my use case. I find that if I connect it to a device (phone, tablet, etc) and place the S9 Pro behind it, the cable is a little too long and sticks out a bit much at the bottom. The cable also came folded in the box, so it has a built in bend to it at exactly the half way mark. However, if I place my device on a stand, the cable is not quite long enough for the S9 Pro to reach the table, so it hangs from the USB port. Again, this is only relevant to my personal use case, it is impossible for a manufacturer to include a cable that is a perfect length for everyone (this applies to all devices, such as headphones, IEMs, amps, etc.).

The clip serves its function well, allowing you to clip the S9 Pro to your pocket or whatever, but if you are using the included USB cable and attaching this to your phone, it means that your phone can only be within 10cm of wherever you clipped the S9 Pro. This can be solved by using a different USB cable but I have found that not all of my USB cables actually work with the S9 Pro and the included one only works one way around. I haven’t investigated this more, so I don’t exactly know what is special about it but it’s worth noting.

Anyway, there is not much more I can say about the build and aesthetics of the device, I think it can be recapped the same way as the “Presentation”, it’s ok but nothing spectacular.



There is nothing really to explain as far as functionality. You plug the USB cable between the S9 Pro and the device you want to connect it to and that’s it, off you go.

My plan, as I said a moment ago, is to be able to use this with my Android devices but also (mainly) with my DAP which is a Shanling M2X. The reason I like the M2X is because it is my preferred size and it is not Android, it lets me get away from the online world while still being able to stream to it. However, the bad news is that my M2X is still at “the doctor”. I had issues with the volume wheel and they replaced it with a new one. The second one had the same issue so I sent it back (to China) again and they have sent me a new one again. Unfortunately this has still not arrived and I have been without the M2X since February!

But all is not lost, I do have the little brother of the M2X, the M0, which is actually a great little device that I keep in my bag also. It may not be the easiest DAP to use because of it’s size but it does (almost) everything its bigger brother can do. This includes two way LDAC communication, and by connecting the S9 Pro to it, I have been able to use certain IEMs with bluetooth that don’t really place nicely with my other bluetooth solutions, such as the B2 Dusk. It has also let me check that the S9 Pro will in fact work with the Shanling (non-Android) DAPs.


This is the strong point of the S9 Pro, it is a very powerful device for its size. Ok, 200mW balanced and 100mW unbalanced might not seem like a lot when we are used to talking about desktop (or larger portable, battery powered) devices but it is the difference between being able to enjoy the sound from headphones and certain IEMs on something this small or not, as the case may be with something like the Apple option (which I believe is around 30mW).

I have used the S9 Pro this week to drive the B2 Dusk, the iSine LX, HE400se, HD6XX and a few others, all getting plenty loud enough for my usual listening levels from the SE output, however, I would suggest moving over to the balanced output for things like the HE400se and HD6XX, as I don’t listen very loud and I was near full output and the sound certainly seemed to suffer. Unfortunately I didn’t have a 2.5mm cable available for these headphones so I haven’t been able to test them out of the balanced output.

The negative side to this much power is that it also consumes a lot of power. I haven’t really done any detailed tests of battery life on my Android devices (I can’t afford to let them run out of battery completely), but using it powered from the M0 while the M0 was receiving LDAC from my phone, I only got around 2 hours out of the M0. When using the M0 in the same way but without the S9 Pro, I can easily get more than 4 hours out of it (and more when playing local files with BT off). Obviously this will all depend on what you are running from the S9 Pro and how loud you like it. For this test I was running the B2 Dusk at my usual listening levels from the SE output.



Ok, the difficult part.

I am not going to do my usual rant about how difficult it is for me to compare clean SS amplifiers, so I will just get on with it.

The sound is very clean, what could easily be described as cold and analytical. In comparison to my JDS Labs Atom (which is currently being fed by a Modi 3+), I would say that the S9 Pro seems to be a little brighter. This could just be me imagining things, but it seems that the treble areas can be a little hotter on the S9 Pro (when listening to the same tracks with the same IEMs at the same volume level, etc.). Would I pick it out in a blind test, I would like to think so, but I probably couldn’t, at least at my normal, low, listening levels.

Other than that, I would say that it accomplishes what I set out to achieve with the purchase of this dongle, it is clean, powerful (for a dongle) and does not seem to impact the sound in any negative way with any of my IEMs. I do feel that my planar magnetic headphones seem to be a little more “alive” when connected to any of my desktop solutions, but that is to be expected, there is really only so much available power we can expect from a tiny bus powered device. The HD6XX also does not sound great out of this dongle, it gets plenty loud enough for me but sounds a little compressed.



I like the S9 Pro, it meets my criteria and does exactly what I wanted it to, but I am not in love with it.

I don’t think that I would choose this as my main listening device, I don’t find myself wanting to use this instead of any of my desktop devices. In fact, I would probably put it in the same group as my THX789, it is not my favourite amplifier but it is a very useful amplifier. I use the THX when I am listening for specific things or comparing specific items, but I don’t find myself sitting down and choosing the THX for a long relaxed listening session, the Hidizs S9 Pro makes me feel the same sort of way. It’s true that it can produce some fatigue on longer sessions.

I am certainly hoping not to go down the dongle rabbit hole but I do think that I will continue to look for something that is portable and more “pleasurable”, although that will probably come in a much bigger (and probably more expensive) package than the S9 Pro.

(this review, along with all my reviews, is also available in Spanish on my blog and on Youtube, visit www.achoreviews.com to see it)


Desktop performance in a dongle
Pros: Desktop power
Ultra clean sound
Sounds awesome in single ended also
Great dac
Great build
Great price
Cons: Gets warm
Eats up power ( worth it )
S9 pro

desktop class performance.

powerful, clean, clear and transparent sound, neutral but full and just right. Lows mids and highs sound great.

balanced and unbalanced outputs

- 3.5mm & 2.5mm connection

- Portability


100mW@32Ω 3.5mm SE / 200mW@32Ω 2.5mm Balanced.

Excellent build and feel

Quality material

Absolutely worth the cost ( around 110$ )

Comes with USB C to USB C cable

Yellow: DSD64/128

Purple: DSD256/512

Blue: PCM176.4/192(Khz)

Red: PCM 352.8/384(Khz)

White: PCM 705.6/768(Khz)

Green: PCM 44.1/48/88.2/96(Khz)

No hardware volume button

Eats power from battery and gets warm

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500+ Head-Fier
The Path to Fidelity
Pros: Great sound.
- Excellent fidelity.
- Plenty of power from both outputs.
- Very good measurements.
- Very useful clamp accessory.
Cons: The device gets warm with use, more so when the volume is high.
- Fade In when starting playback.
- USB cable could be improved.

Hidizs is not giving fans a break. After the fire at the AKM plant in Japan on 20 October 2020, many of the audio devices that used AKM chips have had to move to another manufacturer, due to the difficulty of finding them. This is the case of the S9, which used an AK4493EQ as a DAC. The new S9 Pro uses Sabre's ESS9038Q2M, one of their flagship chips for mobile devices. The external design is largely the same, but the specifications have been improved. Channel separation is higher, harmonic distortion is lower and power is higher, especially in its balanced mode. All other properties are the same. Thus, this new dongle supports DSD521 and PCM32/768, it also has ASIO support and can run on Windows 10 without drivers. Let's have a look at the performance of this new product.

Hidizs S9 Pro 01_r.jpgHidizs S9 Pro 02_r.jpg


Hidizs, offered me this model, in exchange for writing an honest review. I want to make it clear that all my opinions written in this review have not been conditioned by this fact, nor will I ever write anything that I do not really think or feel here. I will only write about my personal opinion in relation to the revised product.

Hidizs S9 Pro 03_r.jpg


  • DAC: ES9038Q2M
  • DSD native DSD64/128/256/512
  • PCM support up to 768kHz/32Bit
  • Build quality: CNC aluminium alloy integration (black, silver)
  • Transmission interface: Type-C
  • Rated output power (SE): 100mW@32Ω
  • Frequency response (SE): 20-50kHz
  • Signal-to-Noise Ratio (SNR) (SE): 120dB (@32Ω)
  • Channel Separation (SE): 80dB (@32Ω)
  • Total harmonic distortion+noise (SE): 0.0012% (@32Ω)
  • Rated output power (BAL): L&R 200mW@32Ω
  • Frequency response (BAL): 20-50kHz
  • Signal-to-Noise Ratio (SNR) (BAL): 119dB (@32Ω)
  • Channel separation (BAL): 118dB (@32Ω)
  • Total harmonic distortion+noise (BAL): 0.0006% (@32Ω)
  • Recommended headphone impedance range: 8-300Ω
  • Dimensions: 18x59x8mm
  • Net weight: 11g
  • Compatible with 3.5mm and 2.5mm balanced headphones.
  • Compatible with headphones with microphone.
  • Works without battery. Plug and Play.
  • Compatible with: Windows, Mac OS, iPad OS, Android, iOS.
  • Note: For iOS users, Lightning OTG cable has to be purchased separately.

Hidizs S9 Pro 04_r.jpg


The Hidizs S9 Pro comes in a sober, medium-sized black box, whose size is 128x83x50.5mm. It is sealed with transparent cellophane. On the top side there is a realistic photo of the device in the middle. The brand logo is in the bottom right corner and the product description in the top left corner. Here, there are also the Hi-Res and DSD logos. The ink of the lettering is silver, with holographic reflection. On the back side, the lettering is only silver and small, but it describes all specifications in both Chinese and English. A little further down, behind a dotted line, is the Hidizs address, a grey sticker with barcodes and the model. Finally, there is also the brand's web address. After lifting the lid, the S9 Pro is encased in a black mould and lined with dark cardboard. With the help of a cloth strap, the device, which is protected with cellophane, can be removed. Underneath the mould, there is also a black cardboard divider that protects the rest of the accessories. In summary, the contents are as follows:

  • Hidizs S9 Pro.
  • Transparent methacrylate case, with clip.
  • USB Type-C male to Type-C male cable.
  • USB Type-C to regular USB adapter.
  • Instruction manual.
  • Warranty certificate.
  • Serial number card.
  • E-Gift Card.
  • 2 Hi-Res Audio logo stickers.

The presentation is fairly sober, with no fuss, and the size of the box and device are proportionate. The accessories aren't many, but among them is the clip-on case, which is a perfect fit, even if it's not the prettiest or sturdiest piece to go with the sleek S9 Pro. On the other side of the scale, there's the USB cable, which is the same as previous products and is still no better in terms of stiffness and memory effect. I would recommend a better cable, with higher quality, cross-section and manageability. Perhaps a braided cable would be a better option.

Hidizs S9 Pro 05_r.jpgHidizs S9 Pro 06_r.jpg

Construction and Design

The S9 Pro is a narrow and elongated piece, measuring 59x18x8mm, made of a high-density aluminium body. The larger sides are glazed. On the top one, there is the Hidizs logo and an LED, located at the bottom, near the USB connector. On the lower side is the Hi-Res logo and a description of the device, in small gold letters.
The shape of the device is like a rectangular box, narrow and elongated, with rounded corners. On the audio output side, however, there are two small, low parallelepipeds attached to the base. Thus, the face of the headphone jacks is larger. These are the 3.5mm SE and the balanced 2.5mm. The connectors are not gold-plated. On the opposite side is the USB Type-C connector.
The S9 Pro has been manufactured using CNC technology, which gives it a premium, elegant and sophisticated look, befitting its class.
Sabre's ESS9038Q2M, a flagship chip in the mobile series, is used as the DAC.
The design is quite simple, only the particular shape of the connector face differentiates it from a simple parallelepiped. The glazed surfaces and the operating LED enhance the appearance and functionality. But it is not a particularly striking or revolutionary design. It is very well made, small and light. You don't need much more for a dongle, unless the connectors were gold-plated.

Hidizs S9 Pro 07_r.jpgHidizs S9 Pro 08_r.jpg


The S9 PRO is compatible with Windows, Android, Mac OS, iOS/iPad OS. It does not come with a Lightning OTG cable, which must be purchased separately. For Windows 10, it is compatible without the need to install additional drivers. However, the ASIO driver from the previous S9 model can also be installed. As usual, the use of ASIO drivers is always recommended. It is also compatible with DAPS that support this type of dongles.

Hidizs S9 Pro 09_r.jpgHidizs S9 Pro 10_r.jpg


The operation is the usual for this type of device, connect, detect and run. In Windows, when it starts playing, it works with a very fast fade.
The existing LED indicates the sample rate, as follows:

  • Green: PCM 44.1/48/88.2/96(Khz)
  • Blue: PCM 176.4/192(Khz)
  • Red: PCM 352.8/384(Khz)
  • White: PCM 705.6/768(Khz)
  • Yellow: DSD64/128
  • Purple: DSD256/512

As a wireless tablet, it is necessary to connect a USB Type-C cable with a suitable connector for the source you wish to use at the other end.
During operation, it should be noted that the body, especially on the glazed sides, becomes a little warm, especially when the volume is increased. In a low voltage regime the temperature is not bothersome. But taken to the limit, as when I took the measurements, i.e. at full power, the heat reached by the device is high, even worrying. I assume that, even so, it is within the "normal" operating range, without suffering any damage.

Hidizs S9 Pro 11_r.jpgHidizs S9 Pro 12_r.jpg


The measurements of the S9 Pro are excellent. Even its power output is clearly higher than specified. Without load, the single-ended output exceeds 2V (2.1V), while the balanced output almost doubles this value (4.1V).

No load SE

As already mentioned, the unloaded output reaches 2.11V @ 1kHz, with very good cleanliness.


15Ω SE

With a 15Ω load, a clean voltage of 1.37V @ 1kHz is reached, which means a power of 130mW and a current of over 90mA, a very high figure indeed.


33Ω SE

But if there is one thing that makes this S9 Pro stand out, it is its performance at 33Ω, its voltage at 1kHz is the same as at no load, which means that the output impedance is close to zero. The cleanliness of the waveforms means that distortion is very low. The power measured at 1kHz, is 130mW, which is well above the specification (100mW at 32Ω). Excellent.


100Ω SE

Nothing to complain about at 100Ω, where the voltage values are the reference values with no load, resulting in a power of 44mW. It is not necessary to calculate the power with higher loads, since, due to the very low output impedance, with loads higher than 33Ω, the maximum output voltage will always be 2.1V. So with a simple count you will be able to know the other power ratings up to 300Ω.


No Load BAL

The unloaded balanced output reaches 4.11V at 1kHz, with excellent cleanliness.



As the current limit of the device is 90mA, due to the balanced output, the maximum it can deliver is around 1.35V, which provides 130mW.



Stretching the volume while observing a clean signal, with this load I have achieved a voltage of 2.75V at 1kHz. It's a little under 90mA, but well over the specified power, reaching 230mW. It's a blast.


100Ω BAL

At 100Ω, the output is already 4.1V at 1kHz, which is 170mW.


Frequency Response

As can be seen in the graph below, the frequency response is completely flat between 10Hz and 20kHz, only dropping slightly less than 1dB towards 40kHz. Crosstalk is also not visible at different volumes and the frequency responses overlap. As it should be.

Hidizs S9 Pro.png


Going back to Sabre's now classic and widely used ES9038Q2M DAC, Hidizs proposes a device whose sound has a neutral and open profile, not overly bright, not overly analytical. I have several devices with this DAC and generally, its profile is not cold. On this occasion it is not either, and it is perhaps the most natural sounding of all the Sabre DACs I own. Although, it is also true that this is not only characteristic of the Hidizs implementation. Be that as it may, and contrary to what I would have liked to find, based on the sound of the Hidizs DH80S, the analytical side of Sabre is not, on this occasion, as prominent as in that model. And this is nothing against the sound of this model, it's just a particular interest of my taste for this kind of sound. But back to the S9 Pro and its sound description, we are faced with a device with a clear flat response and a very low impedance, which means that it will never alter the sound of the connected earphones, respecting 100% the profile of each of them. So one of the words that could define the sound of the S9 Pro is fidelity. Starting, as usual, in the low end, the S9 Pro has a big and concise bass, with plenty of air, something that gives it plenty of room to reproduce, gaining in depth and width. The sound is powerful, but there is a certain softness to it, generated by that level of spatiality. In no case does the level of resolution feel limited by this aspect, leaving its capacity for analysis and definition intact. The separation of planes is clear and the speed of execution allows the bass to be concise and agile, in headphones whose response allows it. In this way, the S9 Pro will be able to extract very good results from headphones with powerful bass.
The open, clear, soft, but concise aspect rises in the central zone. Neutrality is based on that mix of level of resolution, analytical ability, openness and amount of air. The balance is a compendium of all these good characteristics and this is how the S9 Pro's mids are drawn. The result is a rich, again airy area, with a good sense of separation, but without offering a bright sound, where vocals come across as very natural and rich in timbre, with an eminently realistic tone. The instrumentation is according to the same description, offering a concise and rather pure sound, but in a rather sober way that does not incite to spectacularity. This is how one could say that the sound does not arouse passions, but those who believe in the purity of good workmanship will be delighted with this device, since, as I have already emphasised, fidelity without artifice is its best virtue.
Coming to the high end, this is perhaps the most analytical part of the S9 Pro and is where pairing it with the most resolving headphones will be very positive, in order to extract the most juice from a potentially very crisp, clear, separated, fast, defined treble with a good dose of sparkle. At this point, with the help of the balanced output, it is possible to enjoy the purity of the Sabre DAC's sound and its best performance without ever losing balance. Thanks to the S9 Pro's ability to pair with any earphone due to its very low output impedance, synergy with any earphone is assured. And with the good ones, it will be very easy to realise that the amount of air it can bring to the sound is quite large. This results in a very well ventilated soundstage, with clear separation and precise, natural positioning, without the three-dimensionality being perceived as unrealistic or forced. Also, thanks to the innate ability of Sabre's DACs and Hidizs' implementation, the level of detail and nuance extraction will be high, but without being overwhelming or disrespectful to the balance and smoothness of the sound that accompanies the rest of the bands.
Finally, the high power of this new model will be an added attraction to bring our headphone collection to a high level of sound, paired with any source, be it a smartphone, a PC, a laptop or a compatible DAP. With that extra voltage, its two 3.5mm and 2.5mm outputs, the S9 Pro will be pretty much all you need to enjoy music at a high level.

Hidizs S9 Pro 13_r.jpg


E1DA #9038D

The classic E1DA dongle, in its 3.5mm SE output version, has been designed to get the best measurements and maximum power. In my measurements it has given a value of 160mW at 33Ω, which exceeds the 130mW at 33Ω, measured in the S9 Pro, a real barbarity. On the downside, it has no balanced output and its decoding goes up to PCM 384kHz/32bits, DSD256. The S9 Pro goes up to 768kHz/32Bit and DSD512. Its size is slightly smaller and flatter. The price is also lower, but the packaging is very simple and there are no accessories. It only has a small operation LED. Both use the same DAC and their sound is quite similar. In my listening using the comparator it was very difficult to find any differences between the two devices. Their presentation, profile, tone and timbre are very similar. I noticed that the bass texture of the #9038D is rougher, somewhat richer, offering a bass with more depth, slightly more pronounced. The S9 Pro, on the other hand, is slightly smoother. In the mid-range I'm not really able to distinguish much distance either. What I have been able to appreciate, or thought I did, is that the greater power of the E1DA seems to give it a slightly higher level of transparency, clarity and space than the S9 Pro. But the positioning of the voices, their tone, instrumental recreation, timbre and many of the sonic aspects are still very similar. However, it was in the high end that I found the biggest differences between the two devices. If up to now, the E1DA seemed to have an advantage over the S9 Pro, in the high end, in definition and detail extraction, the Hidizs proves superior, offering a sound with more sparkle and less flatness than the #9038D. Thus, the S9 Pro seems to have a more dynamic feel, more evident nuances and a more vivid sound in this high range. These aspects may even appear in female vocals, benefiting from this brightness to be better positioned, more evident, present and palpable, in the Hidizs. Thus, while the E1DA offers a more powerful bass range, the S9 Pro offers a superior richness in the upper range. In terms of soundstage, as I have already mentioned, the #9038D is a little cleaner and wider, but the definition of the high end matches this aspect.
Having discussed the sound differences, it is worth noting that the Hidizs has a balanced output, with its higher power, in addition to the conventional 3.5mm SE. This is something that could tip the balance towards the S9 Pro, without a doubt, as it makes it a more versatile device and also more capable at decoding high-resolution files.

Hidizs S9 Pro 14_r.jpg


This little device is one of my favourite dongles. I think there is little else that comes close in performance and sound for the price. It is clear that the Hidizs S9 Pro does not have many of the features of the 5K (Bluetooth, control APP, control buttons, in-body clamp, battery). However, it does have a higher level of decoding (768kHz/32Bit and DSD512), compared to the 24-bit/96kHz, no DSD playback in USB DAC mode of the 5K. On the other hand, in power they are very similar, with the S9 Pro at 33Ω being more powerful due to the SE output (130mW vs 110mW). However, the Qudelix is more powerful due to its balanced output, reaching 260mW at 33Ω, compared to 230mW at 33Ω for the Hidizs. The 5K has no ASIO drivers and its DAC is the Sabre Dual ES9218P. Both devices have an output impedance of less than 1Ω.
If with the previous device the differences were small, between these two, the sound is once again very similar. Not surprisingly, it is once again Sabre vs Sabre. And the fact that the Qudelix has a Dual DAC allows it to compete with Sabre's top of the range DAC. After several hours of comparisons, my feelings are subtle in this respect. A priori, I find the Qudelix a little more analytical, where the smallest details and nuances seem to be revealed more easily. However, I get the sense that the S9 Pro sounds more defined and higher resolution, offering a darker background, a little more separation and air. In the low end of the S9 Pro, there is a little more punch and speed, when playing the lower range. Lower notes seem to be reproduced more concisely and tightly on the Hidizs. On the other hand, the 5K's vocals are a little more present and closer, sounding a little more complete.
As for the scene, slightly cleaner and wider on the S9 Pro, with a bit more air and separation, plus that slightly darker background.
It is a difficult choice between two great dongles. But the preference for one or the other should be based on two aspects: if you want to play music with the highest fidelity and quality, I would choose the Hidizs S9 Pro, because of its ability to play PCM up to 768kHz/32Bit and DSD512 and because its sound is slightly superior. But if you want to use Bluetooth and exploit all the capabilities that the Qudelix offers with its APP, it is clear that the choice will be the 5K. And on this I can't fool anyone.

Hidizs S9 Pro 15_r.jpg


The fight for the best dongle is fierce. There are more and more models, they are cheaper and they sound better and better. And Hidizs is following the path described above. The S9 Pro is cheaper than the S9, even more powerful. In addition, they have opted for a superior DAC. As a result, its sound has great fidelity and is on a par with more expensive and larger devices. Even with the level of power and the dual audio output (SE and Balanced), the comparison with other similar or superior devices starts to be odious. For example, the S9 Pro is superior in power to the DAP HiBy R3 Pro and with our Smartphone, we don't need anything else. Is it getting to the point where Dongles are displacing DAPS? It is clear that in terms of sound, yes, and they are cheaper, as they are simpler devices, lacking many elements (screens, batteries, card reader, more complex firmwares...). And in the real scenario, where everyone has a mobile phone, potentially, they also have a very high quality sound system, just by adding an S9 Pro. And that's a big advantage.

Hidizs S9 Pro 16_r.jpg

Earphones and Sources Used During Analysis

  • HiBy R3 Pro
  • Xiaomi Redmi Note 8 Pro
  • Hidizs MS2
  • Reecho SG-03
  • BGVP ArtMagic VG4
  • ISN H40
  • NS Audio NS5 MKII Extra Bass
  • Tin HiFi T4
  • TFZ Live X
  • Rose QT9 MK2
  • Ikko OH10
  • BQEYZ Summer
  • Takstar Pro 80
  • NiceHCK EBX21

Hidizs S9 Pro 17_r.jpg


  • Construction and Design: 90
  • Packaging and Accessories: 80
  • Connectivity: 91
  • Operability: 75
  • Sound: 91
  • Quality/Price: 93

Hidizs S9 Pro 18_r.jpg

Purchase Link:


You can read the full review in Spanish here:


Hidizs S9 Pro 19_r.jpg
Thank you for your words.
I am sorry to comment that I do not have the Shanling UA2. Well, actually I don't have any Shanling, nor have I been able to test it on any Tour in my country. :sweat:
  • Like
Reactions: niron
@niron The Shanling UA2 is similar, but I believe the looks & build quality on the S9 Pro is noticeably better. The Fiio KA3 is virtually the same as the UA2 in performance and price (a smidge lower than the S9 Pro) but personally I trust Fiio over Shanling so take your pick. ¯\_(ツ)_/¯
  • Like
Reactions: niron
@Results45 Thanks, already picked up the Shanling UA2 and it's just great. Now considering to upgrade my dongle to Cayin RU6.


500+ Head-Fier
Hidizs S9Pro – more power, more drive
Pros: high power output, balanced output, durable, sounds good
Cons: no control buttons

About a week ago Hidizs has announced the launch of a successor to its highly popular balanced S9 USB DAC/amp that is already on pre-order state. We have reviewed the original S9 some time ago and defined it as highly recommended for those who want to upgrade smartphone/tablet/laptop sound and squeeze out much more juice from music quality.


New version gets PRO suffix due to some significant changes in HW that increases output power and improves other characteristics of this small but mighty device. While the exterior left untouched, main differences are hidden under the hood and here is the table that compares all generations of “S” series units:


This table discloses the main improvements and changes in new S9Pro. For us, the most important is the output power that has increased from 90 to 100mW @ 3.5mm SE output and from 120 to 200 mW @ 2.5mm BL output. Hell lot of additional power on balanced port. Not sure how Hidizs has managed to do that while maintaining similarly small package. Perhaps, shifting from AKK5593EQ to ESS9038Q2M made it possible and also improved other sound spec-related values. For now, it seems that S9Pro is one of the most powerful USB stick-type of DAC that doesn’t rely on its own battery. Just think – it is more powerful than AP80Pro (190mW on 2.5mm BL) with larger dimensions and LiON battery inside which is completely enough to drive 150Ohms overheads…


Anyway, now about S9Pro full specs:


What we have noticed just now is that specs declare that S9Pro is compatible with mic equipped earphones. Good to know that when such device is connected to a smartphone you would still have a possibility to accept calls and have a conversation without switching to internal phone mic or loudspeaker. Although, we would still check how can it be possible when S9Pro is occupied by something like HiBy Music app in exclusive USB audio mode. Usually, such mode won’t let other sounds from the system mixer to pass through… Not enabling this mode would solve such problem but the sound might be affected by the system processing. We would give our feedback on this further in this text.


Packaging and design:

Nothing much has changed in terms of packaging. It is still logistic-friendly small matt black box but instead of silver outlines new box has glossy product picture on the facing side. Box is stiff and comes undamaged after a long trip from China to other parts of the world. Internal box structure consists of two compartments where the device is located on top in a special soft insert and all accessories are stored underneath. Contents are:
  • S9Pro DAC/amp
  • transparent plastic holder / clip
  • USB type C -> USB type C cable (65см)
  • USB type C -> USB type C cable (15см)
  • USB type C -> USB A adapter
  • leaflets, cards…

Design of this unit has not changed either, therefore we would comment ourselves next:

S9Pro is a small unit (close to AA battery size) but still shows quite complicated design. It’s shell is made of aluminum (CNC) whereas both front and back sides are covered with glass panels. Such approach is inherited from other Hidizs products and resembles the design principles of this brand.


Personally, we like such approach which adds the value to the device in terms of overall feel. In fact, S9Pro feels very solid and durable while looking pretty for its combination of aluminum and glass. There are no buttons and no screen, side edges are left free of any elements. USB type-C port is located at the bottom edge and both SE & Balanced ports are situated one over the other on the thickest part of the shell — its top edge.


The only indication that S9Pro has on board is represented by semi transparent Hidizs logo under the front glass panel. Not only it gets lit upon incoming power supply, but also its colors are synchronized with the sampling rates of played tracks.


Plastic clip / holder that comes as a part of the bundle is really great accessory. It securely holds S9Pro at place, protects it from physical impacts and allows to attach it to clothes. It doesn’t limit the connectivity or usability of this device. Both short and long cables are similar — soft and flexible transparent braid, aluminum type-C connectors and banding protection at both sides. USB type-C -> USB A adapter is applicable whenever someone wants to connect to laptop or PC.


Device in use:

Since S9Pro has type-C to USB A adapter along with type-C cables – we can try it with laptop/PC as well, not only with Android smartphone. In case of a smartphone everything is straight forward: use type-C to type-C cable to connect devices, HiBy Music App to send audio data over USB. S9Pro gets recognized as USB DAC and there are no problems whatsoever. S9 LED color would resemble track quality:
  • Yellow: DSD64/128
  • Purple: DSD256/512
  • Blue: PCM176.4/192KHz
  • Red: PCM 352.8/384KHz
  • White: PCM 705.6/768KHz
  • Green: PCM 44.1/48/88.2/96KHz

The only small inconvenience here is the absence of control buttons on S9Pro. Volume is being regulated on a smartphone for USB device and might be at its maximum upon initial connection. It might be harmful for sensitive, low impedance IEMs. So, just keep in mind to set the appropriate volume level after connecting S9Pro to smartphone before hitting playback.


In case of Windows 10 laptop/PC – S9Pro gets natively supported as USB DAC but there would be a dedicated ASIO driver that was announced by Hidizs and should become available for download a bit later. Initial S9 already has this driver and S9Pro is on the waiting list. ASIO drivers would give the most sound quality while native Windows 10 driver would have the lowest audio lag possible.

S9Pro shell gets warm during operation but not much, around 32C with SE output and 37C with BL output.



Tested with Xiaomi Redmi Note 8Pro, Lenovo Y500, Hidizs MS2 SE and Hidizs MS2 BE, Audio-Technica ATH-M50.

Repeating the success of its predecessor, S9Pro can easily be compared to best representatives of entry level DAPs — significantly better than vast majority of smartphones with their weak sound output and similarly better than even most of the laptops. Smartphones can’t perform with such clarity, can’t retreive this much resolution and its dynamics lacks power.

S9Pro is much better in resolving lower range, retrieving good amount of textures and its mid bass performance is way ahead. Extension of the lower end gets increased, lows gain in clarity and give a feeling of volume. It is much better separated from mids. Although, lower end is is not accented in S9Pro and this unit definitely not tending to dark signature.


Resolution on mids is somewhere close to AP80Pro DAP, maybe slightly less obvious… Slight tendency to bright delivery is present, making a bit more accent on female over male vocals. Still male voices sound pretty thick and natural. Great amount of details retrieved from upper mid range. S9Pro on mids is definitely sounding more transparent and rich than muddy and mixed result of the same track coming from a smartphone.

Treble is also handled much better, it is more clear, crisp and airy. Extension is greatly increased, making the entire sound picture brighter and detailed on the upper end. Small amount of sibilance is present with some sensitive IEMs but absent with overheads. In general, this range is accurate and in a good balance with mids and bass.


Similarly to S9, Pro version can greatly improve every aspect of the sound on a smartphone or laptop that don’t feature dedicated, good quality DAC. Both devices sounds more natural and at the same time deliver more details with better extensions and stronger dynamics. This goes to both output types, while 2.5mm BL is twice as powerful – making stage slightly wider and instrument separation slightly better.

Finally, yes – we have check whether HiBy Music app would allow other sounds to pass to USB device in USB exclusive mode: no, it won’t let it pass. Therefore, in order to use mic and talk over S9Pro – USB exclusive mode is not used and audio quality might get worse due to Android OS mixer being used.


Compared to Hidizs S9:

S9 and S9Pro have common exteriors, similar philosophy, compatibility and features. Although, sounding slightly different. Since S9Pro has significantly more powerful 2.5mm BL output – it has better drive and dynamics that results in more punchy mid bass. Slightly more bright and colder picturing makes upper end more detailed and crisp. Instrument separation seems to be slightly better and stage a bit wider. At the same time, S9 is still a good unit since it is thicker on mids and tends more towards lows.


Compared to Hilidac Beam 2:

The main advantage of Beam 2 is MQA support (if you are still not disappointed with it). It has slightly more power on BL output but doesn’t support this much of PCM or DSD as S9Pro does. Sounds pretty much similar, with slightly wider stage but more prone to sibilance and even brighter. The main disadvantages: more expensive and both outputs are located on the side which makes it less convenient to store in a pocket.



With the release of the initial S9, Hidizs has proven than even a small power-dependent USB DAC can be powerful enough and sound as good as most of the entry-level DAPs. Now the successor, S9Pro – sets the new standards on the market for such tiny audio companions in terms of maximum output power and driving ability as a consequence. This also results in unexpectedly reach sound, large amount of textures and details, good extensions at both ends, sufficient dynamics and enlarged stage. All of that produced by a small unit, enclosed to durable aluminum chassis that does not require charging and doesn’t weight anything… Perfect and small, with large sound!

Permanent promocode at Hidizs store for 10% discount: ZMCR10

Hidizs S9Pro on pre-order: LINK
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