Hidizs S9Pro

"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")



BASS/LOWS:


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.



MIDRANGE:


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.



TREBLE/HIGHS:


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.



GENERAL TECHNICALITIES:


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.



PEER COMPARISONS:


AUDIOQUEST DRAGONFLY BLACK (2016)

• 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 *




P.S.


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.

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.



Connections

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.



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).



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.

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.



Presentation…

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.



Functionality…

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.

Power…

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.



Sound…

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.



Conclusion…

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)