The Hidizs XO is the new ultraportable amp/DAC adapter for smartphones and computers designed by Hidizs.
The XO Pro has a CNC aluminium body and very sleek design, with a LED indicator that has several color patterns, which can be indicate a different digital filter (selected through the large dedicated O-shaped button) or the sampling Rate of the music being played. The colors come out also from the sides of the XO (where several, small H shaped holes are etched).
The Hidizs XO is super tiny: it measures 55 mm * 24.5 mm * 9.35mm , so it is slightly shorter than the S9 Pro and slightly wider. It can fit any situation, and its clip can be perfect for pockets. It’s only 11 grams in weight.

The Hidizs XO features two ESS9219C DAC chips and supports MQA format up to 16X, PCM 32bit/384kHz and DSD258.
Just like the S9 Pro, the Hidizs XO has two headphone outs: balanced (2.5mm) and single ended (3.5mm).
The output power is rated at 78mW@32Ω per channel in single ended mode, and 195mW@32Ω per channel in balanced mode. SNR of the device is also quite high: 118 dB in single ended mode, 119 dB in balanced mode.
The Hidizs XO is capable to power portable headphones, IEMs and some (efficient) full size portable headphones.



Connectivity

The Hidizs XO has a USB Type C input and can connect to Windows and Mac OS computers, as well as Android and iOS smarthpones. It’s plug and play, no installation of external drivers is required.
The XO doesn’t have an integrated battery and powers up when connecting to its source device.
Included in the box is a short Type C-to-Type 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 tested the XO with my Windows 11 PC and Google Pixel 7 Pro Android smartphone.



Sound Quality

I have tested the Hidizs XO Pro with my Etymotic ER4P, Momentum over-ear and Hifiman R9 and even Edition XS.
The XO presents a very clear, slightly bright sound signature. Against the built-in headphone out of my PC and smartphone, it provides much more headroom, much better level of detail, higher treble energy, better bass definition. The sound is more spacious.

The bright character of the XO makes it especially good to match dark headphones like the Hifiman R9 and Sennheiser Momentum.
The first combination is particularly amazing, sounding better than hooking the same headphone to much more expensive and powerful amplifiers (such as DNA Stratos). The R9 is a dark headphone, with rolled off top end, and with the Hidizs XO it ends up sounding extremely balanced, detailed, and extremely good for a combination that costs under 400 USD as a whole.

With Sennheiser Momentum, the overall sound is similarly balanced but less detailed, because the Momentum scale less as far as details/transparency go.
Etymotic ER4P don’t match very well with the XO, because the brightness of the headphone and the device add up and there is too much treble energy. Anyway, even so, connecting the XO with the ER4P shows that the no noise floor (hiss) is picked by such an efficient IEM.
The Hifiman Edition XS poses an excessive load for the Hidizs XO to handle, resulting in an underamplified sound (poor instrument separation, screechy treble): it simply tells us that the headphone is too much for such a tiny device.

The XO has two optional digital filters, which are selected and identified with lights: Blue Light is supposed to reduce the by 20-30%, while Red Light should reduce by 30-40%. With my tests, though, while I did notice mainly an increase in bass fullness, using digital filters with combinations of XO and trebly headphones did not change the overall character enough. In the end, I would prefer to select my headphone carefully rather than playing with digital filters.



Bottom Line

The Hidizs XO has several positive points: it has much more powerful and cleaner output compared to a standard device (PC, smartphone); it’s small, light and easy to wear; it is extremely cool (its light patterns make it feel alive). It can reach high volumes and low distortion with several portable headphones, and can also work with full size headphone that aren’t too demanding (such as the Hifiman R9).
Matching the XO with headphones that have a subdued top end can create a special sinergy, and end up producing highly budget-efficient portable systems.

The AP80 Pro-X is a portable digital audio player made by Hidizs. This player is the bigger brother of the AP80, upgrading from ES9218P to ES9219C DAC chip in order to improve performances and extend format compatibility to Tidal MQA. Furthermore, the AP80 Pro-X has a 2.5mm balanced headphone out in addition to the standard 3.5mm headphone jack for single ended headphones.
The AP80 Pro-X has an extremely small footprint and can be carried very easily as an additional device. It’s one of the smallest stand-alone players on the market.



Controls

The AP80 Pro-X offers many physical controls in order to not take it out of the pocket during usage. On one side, there are the play/pause button, the song skip (prev/next) controls and the volume wheel, which also works as power button.
The controls are overall sturdy, with the execption of the wheel which is a bit flimsy.



Connections

At the bottom, the AP80 Pro-X has the two headphone outs (balanced and single ended) and a USB-C connector, with which it can be used as external DAC (controlled externally from a smartphone or from a PC), or which can be used to connect the AP80 Pro-X to an external DAC/amplifier.
On the left side, there is a micro-SD card slot, if the user wants to store music on the AP80 Pro-X.
Finally, the AP80 Pro-X can work as Bluetooth DAC/amp, sending music streams and controlling it wireless from an external device.



Sound Quality

The AP80 Pro-X has a full sounding, darkish signature. Unlike many portable devices, vouched for a U-shaped frequency response to make bass and highs more forward (thus sounding aggressive), the AP80 Pro-X has a warm sound and natural treble roll off. Such traits are reduce the possibility of sibilance, and work great with a wide variety of headphones/IEMs, although they will have some issues with others.
The full tonality is e with with flat / bass light /bright earphones, such as Etymotic ER4-P, Hifiman RE800, Hidizs own MS2. On the opposite end, with Sennheiser Momentum the midbass is too much, and the gentle treble roll off of the player is summed to that of the headphone itself, resulting in treble energy being too tamed.



Bottom Line

Who’s going to benefit form the a player like the AP80 Pro-X?
First of all, people who have a new generation smartphone (which lacks headphone jack) and would like to keep using their wired high-end portable headphones/IEMs, without the hassle of using a Type-C/3.5mm adapter (or Thunderbolt/3.5mm adapter in case of iPhones): the AP80 Pro-X can be operated independently or, even better, as a Bluetooth external DAC/amp (as I do), taking advantage of your favourite smartphone music player app and sending the music directly to it.
Second: obviously, people who have a balanced portable headphone (with compatible 2.5mm connection).
Third: if, in presence of a smartphone with a headphone jack, the output is too low for the chosen headphone, as the AP80 Pro-X is more powerful (while offering fine tuning thanks to the wheel) than a regular smartphone.
Last case, when owning neutral or lean-sounding high-end IEMs/earphones/headphones, which, as said, will benefit from sinergy with the AP80 Pro-X.

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.

This is my review of Hidizs Mermaid MS2. Listening to them has been a great surprise, as they are a very good sounding IEM for an extremely affordable price.
Note: Hidizs has kindly sent me a pair of Mermaid MS2 for this review. While appreciate their kindness, this will not influence my opinion in any way.



Structure and Fit

The Mermaid MS2 are a hybrid IEM, which use two drivers per channel. The low frequencies are taken care of by a 10.2mm large dynamic driver, which manages to produce full bodied bass frequencies, while the middle and high frequencies are managed by a balanced armature driver, which, thanks to its fast impulse response, can render tiny details and separation layers precisely. This hybrid nature exploits the best of the two technologies to cover the full spectrum, and confers the IEM a quite high sensitivity (112 dB), thanks to the inherently high efficiency of balanced armature drivers.

While not small, the MS2 is very ergonomic and sits perfectly in my ears. I am positively surprised by this because, frequently, several other multi-driver hybrid IEMs I tried feel quite big in the ears (as an example, Dunu DN-2002 and 3001), because of a large housing, but this is not the case.

The MS2 comes with a quite wide selection of single flanged silicon eartips. Personally, because of the shape of my ears, I prefer to use comply foam tips or dual flanged tips that I have bought separately. Regardless, what is important here is to reach a correct seal (for sound) and have a comfortable fit (for the user).



Aesthetically, the MS2 can come in a dark color palette or, like in my case, a marine-light blue color palette, which I find gorgeous. The Mermaid MS2 is designed to be worn upside down, passing the cable over and behind the ear.
The removable cable has an almost pink color, it’s a high quality braid of 2 braided silver wires and 2 braid OFC wires, and it’s extremely flexible, which adds to the overall comfort and absence of microphonics. The cable connectors to the earpieces are 2-pins per channel and, just like the 3.5 mm jack, looks very sturdy.


Sound Quality

The MS2 is energic, full bodied, natural sounding and detailed.
On the bass side, while it lacks the ultimate depth, it has the right amount of midbass to be both powerful and create the “foundation” for the remaining parts of the spectrum, and to not feel rubbery nor cavernous (no excessive resonance). While “deep bass” is desirable (also because of the difficulty to achieve it), the midbass (and more in general, what is in the middle) is more important because it has many more chances to ruin the sound if rendered incorrectly.
The midrange is natural, slightly warmish, an area around 2 kHz might be very slightly recessed (probably, just in comparison to the midbass and lower midrange) but it never sounds distant.
The high frequencies are very slightly accentuated, improving clarity, layering and spatial capabilities, without showing any hints of sibilance.
The overall picture is that of a vivid, present, balanced sound.



Bottom Line

Hidizs Mermaid MS2 is a wonderful earphone. It has very good tonal balance, it is neutral, smooth and pleasant to listen to. It’s a great all arounder with all music genres.
As already stated, it’s very ergonomic. On the website, it’s stated that the dark colored version and the blue-marine colored version have some differences in fit, so, having tried the latter, I would definitely go with that.
The Mermaid MS2 is built like a tank, comfortable, beautiful and uses great materials. The removable cable is fantastic in quality and flexibility.
Furthermore, it comes with a high quality carrying case (which, to me, looks true leather).
All these features at under 100$ were unthinkable until few years ago, which make it a bargain and a safe purchase even at higher budgets.

DUNU has a significant history in producing multi driver, hybrid IEM's, which I am very fond of, because of their amazing sound and quality vs price ratio.
I have already shown my love for the DN-2002 and DK-3001, among my absolute favourite IEM's ever.
The biggest complaint I have been reading about them, has been the size and comfort: to house their complex combinations of drivers, DUNU had to make some compromises in the size of the housing, which is a bit heavy for the ears of some people. I usually tame comfort issues by using comply foam tips, which are much more comfortable than silicon tips; still, smaller in-ear monitors are generally more comfortable, regardless of the tips used.



The new DUNU Falcon-C is a single dynamic driver In-Ear Monitor, which borrows from the sound signature of the DK-3001, while making the design simpler in order to achieve a smaller and ergonomic earphone.

As its bigger brothers, the Falcon-C has a removable cable. In the past I wrote that I would have prefered a better connector for the removable cable of DUNU's (and other producers') earphones, it's finally been upgraded.

<strong>Sound Quality</strong>

The Falcon-C is a powerful sounding IEM, energic, slightly U-shaped, but tonally intense.
It has high speed, fast decays, and the capability to be toe-tapping, involving, using the bass-vs-treble balance as a mean to add up to the sense of pacing.
Just like its bigger brother (the DUNU DK-3001), it's a "special" U-shaped frequency response, meaning that the powerful bass and extended highs are not burdening the midrange, which is actually very vivid and makes vocals full, never recessed.



Compared to the DUNU DK-3001 (which more than twice as expensive), the Falcon C has similar musical flow and balance between ranges of frequencies, but the DK-3001 have more control in the higher frequencies (slightly tilted, but never sibilant) and clearer layer separation.
The Falcon-C is slightly tilted in the upper midrange to middle treble, so that vividness is also accompanied by some sibilance in certain cases. Certain cymbals, especially on poorly recorded music, as well as certain singers with very sharp "s", can sound a bit too hot. This issue was more noticeable before burn in, but got much more controlled after 40-50 hours of listening.
Compared to other neutral, bright sounding IEM's, like Etymotic ER4, the Falcon-C sound more realistic, have similarly rendered treble, and have fuller, more natural bass, perhaps less deep in frequencies than ER4, but overall more tuneful with the rest of the music.

The soundstage of the Falcon-C is intimate, and in tune with the midrange vividness, making it especially tuned for rock, metal, jazz and generally music played by small groups. Classical music would take advantage of larger sounding headphones, which would render better the spatial localization of large orchestras.



<strong>Conclusion</strong>

The DUNU Falcon-C is a very comfortable IEM, that feels small in the ear, and have very appreciable sonic qualities. It's realistic sounding, fast, detailed, ideal for several music genres. It takes obvious inspiration from the sound signature of the DK-3001. While not being quite up there in overall sound quality (the DK-3001 is a giant, and is much better than severall over 1k Euro headphones), it's much more "portable", comfortable, and never causes phisical discomfort. The removable cable is very good, the new MCX connector is sturdier than the one used before, promising much longer durability.
I would advice it to everybody that doesn't listen mainly to poor recordings prone to sibilance, like rock from the 60s/70s: it's, for all other purposes, a very convincing portable headphone for the go, and in the 200$ price range, it offers several desirable qualities for a very reasonable price

One year and half ago, I reviewed the Dunu DN2002 and found them to be one of the best sounding IEM’s for the price. They were very neutral, rich sounding, both in terms of tonality and detail retrieval.
Their biggest quirk was a large housing for the hybrid driver design, discomfortable to several users, especially in the ability to keep the seal between the eartips and ear canal. The problem could be solved by using foam tips, but they would still feel quite large and heavy. The sound, though, was amazing.

After several months, DUNU finally put the DK3001 in production, with a different driver assortment compared to the DN2002: where the DN2002 are composed of two dynamic drivers and two balanced armature drivers for each channel, the DK 3001 use 3 balanced armature drivers and one dynamic driver for each side.
DUNU is not new to experimenting with so many creative solutions in terms of driver combinations, and this sets them apart from most manufacturers.
As a start, the DK3001 is a bit more comfortable than the DN2002, the housing is more balanced, although still quite large.

In terms of sound signature, the DUNU DK3001 are a side step to the DN2002. The DN2002 has slightly rolled off highs, excellent midrange, and very good bass response. The DK3001 has more bite. The DK3001 is a slight U-shaped take over the DN2002 signature. It has, primarly, more aggressive-energic high frequencies, and more powerful bass. They retain the sense of naturalness and warmth of the DN2002, but everything is a bit more tilted, rhytm inducing, toe tapping. The general sense of satisfaction is drawn by both the fullness and the “kick” coming from the bass liveliness and treble richness. The more powerful high frequency output, compared to the DN2002, translates to a crisper perception during the listening sessions. Still, the higher volume is perceivable without being sibilant: this means there aren’t any spikes in the lower / middle treble, which would have proven unpleasant. The treble response must very extended, rolling off only at very high frequencies, and gently. I guess the three balanced armature drivers taking care of the midrange and treble frequency range, allow for fine tuning and lack of regions that can get out of control.

Usually, I wouldn’t regard a “U” shaped headphone much, because in most cases, this would mean “sucked-out midrange”, and hollow signature. But the DK3001 is so organic, natural sounding and the additional crispness and bass impact over the DN2002 are more akin to adjustments. I would say both are on a similar level, where the DN2002 has a lower profile approach, naturally letting the music flow and almost disappearing, while the DK3001 give it push and could actually be preferable due to the stronger sense of “feeling” the music, the additional sense of speed, transparency, refined treble and slightly more comfortable housing.

There is something that I would see from Dunu, though, and it’s related to the connectors used by the removable cable plug/socket design: MMCX connectors, in the past, gave me some problems, getting loose over time (for example with my TFZ earphones). In my experience, a 2 pin connector would be more reliable in the long run.

This is the only fault I can really find in this product, which is otherwise stellar in its price bracket and can compete, and kill, models costing twice as much.

The SOtM sHP-100 is a portable dac/amplifier combo designed for computer audio. It's built on the same principles as their sMS-100 music server, which means tiny size, ease of transport, and good value for money.
Some of the most meaningful specifications follow:
 
DAC Chip: Cirrus Logic flagship CS4398
USB Class 2.0 input, using a XMOS multi-core RISC processor, support for 24bit/192kH playback and DSD x64, x128
Optical, Coaxial inputs with AKM AK4113 chipset and support for 24bit/192kH playback
Analog Output: LME49720 and TPA6120A2 opamps
ALPS volume potentiometer

The sHP-100 uses special ASIO driver which can be downloaded on SOtM website. The installation is quite straightforward, only requiring to pay attention to one thing: if using Windows 8 (or later version),  the user must install the drivers in compatibility mode, by clicking on the setup.exe file, selecting properties -> Compatibility mode tab, “Run in compatibility mode for” checkbox, and choosing Windows 7 in the drop down menu.

The sHP-100 is a perfect solution for work environment, it's low profile and I personally use it at my office desk, with my Sennheiser Momentum. It's much better than listening to music from the computer from a headphone out (I find it untolerable) as well as a mobile phone, and looks/questions from collegues tend to disappear very quickly. It’s also much easier and low profile to operate than a high end DAP, which would need to be controlled by hand (and not within the computer). Out of curiosity, I have even tried Xiaomi's pistons (which a collegue kindly lent me for the occasion) and they sound much, much better, with much better separation, clean (and pulsive bass), and an overall interesting, toe tapping sound. The Sennheiser Momentum are obviously much better and retain their character, but improve strongly in stereo separation and imaging, compared to my regular portable usage (which involves two very good sounding Android phones, the Moto X 2014 and Photon Q, both of them I rate much higher than any iPhone).

The sHP-100 has a neutral character. It’s a character that’s very flexible, allowing for the sound to be fine tuned by other elements in the audio chain (in my case, the headphones). It doesnt have any kind of peak in the treble (no sibilance), nor any excess in the bass area. The bass is clean and quick, it doesnt have the ultimate punch, but in this regard it’s not worse than DACs like Metrum Octave Mk2, jKenny Ciunas, Yulong D200, Mytek 192.
While not having the same magical midrange of certain Metrum DAC’s, and some other analogue-sounding DAC's, it has a smooth, pleasant balance, and doesnt sound recessed. It's also free from the kind of digital glare found in Sabre DAC's. Due to its neutrality, it doesnt interfere with the frequency response of the headphones and this aspect makes it very adaptable, since no frequency range overpowers the other.
I have been using the portable battery with it, but to the the improvement was not major with the Sennheiser Momentum (and Momentum 2.0, which I also tried for a brief period with it). It's possible that the perceivable gain from adding the battery PSU (or a regulated PSU) varies depending on the headphones used: the Sennheiser Momentum and Momentum 2.0 are very easy to drive; on the other extreme, having tried my HifiMan HE-1000 for fun, I found some better definition and bass heft with the battery usage, but those require a monster amplifier (I normally use the MacIntosh MHA-100), and the overall amplification section is just not enough. Better tailored choices for what the sMS-100 ìs (and to appreciate the improvement of a battery) could be the Audio-Technica AD2000 or Grado RS-1, which are more demanding than my portable Sennheisers, but still reasonably easy to drive by the SOtM amplification circuitry.

For home usage, it could be a great choice to pair the sHP-100 DAC output (which is the highest point of the sHP-100), with something like a Stax Lambda system, or SRS-005II system, for very high quality sound on a budget.