HIDIZS XO

I must begin this review with an apology to Hidizs! I received the product reviewed here several months ago. Unfortunately, moving to a new house and preparing to start a new job delayed the publishing of this review.
As I began to compose this review of the Hidizs XO dongle DAP and amplifier, I started counting and realized that I have purchased a lot of their products over the years.

It all started when I had a pair of the Blon-03 IEM's (which you may remember were all the rage a number of years ago, said to be the latest, low-priced "giant killer" IEM on a number of headphone forums and YouTube reviews).
Sometime later, after I purchased the EarStudio ES-100 Bluetooth DAC/amplifier, I really wanted to try the BL-03's with the ES-100's 2.5 mm balanced output. Looking on Amazon.com, I found the perfect cable, at a very reasonable price, made by an unknown (to me) Chinese company called Hidizs. The cable came, nicely packaged and of good quality, and it did the job.
More of their products followed. Based on a rave evaluation from the website Audio Science Revue, I purchased the Hidizs S9 Pro dongle DAC, which sounded great. I especially like the industrial design: metal around the edges and glass on the front and back. It looked and felt like a high-quality product, at a very reasonable price.

Much later on, as Hidizs began to expand their product lineup, I was intrigued by their tiny AP80 Pro X digital audio player and matching amplifier, and gave it a try, as well. The sheer "cuteness" of that diminutive player combined with the matching DH80 DAC/amp, yielded remarkably fine sound quality.
The combo impressed me enough that when I learned that the company was looking for customers to review their new XO, MQA capable dongle DAC and amplifier, I wanted to give it a try. I was particularly interested because I still have the company's older S9Pro DAC/amp combo dongle, and wanted to see how the two of them compared.

The usual disclaimer: Hidizs supplied me with a sample of the XO product in exchange for this unbiased review.
There are already lots of reviews of the XO on Head-fi.com, many of them duplicating similar information such as the manufacturer specifications, un-boxing photos and so forth. In this review, therefore, I'll focus on my listening impressions, and some comparisons that I haven't seen elsewhere.
I tested the XO with two different IEM's, the Campfire Andromeda (2019 version), and Hidizs' very own MP145 planar magnetic earphones. I was also very curious to try the XO driving my Audeze LCDi4 planar magnetic IEM's, but they require equalization to sound the way they should, and I didn't have the time to install and configure a systemwide equalizer on my 14 inch, M3 MacBook Pro. When I do have the chance to try that, I will append the results to this review.

Physically, the XO is slightly shorter but substantially wider than the older, S9 Pro. The additional width possibly results from the fact that the XO places its two headphone jacks next to each other, whereas the older S9 Pro stacks its outputs vertically, necessitating a somewhat awkward bulge at the output end of the dongle.
Anyway, the build quality of the XO seems fine. I do like the rose gold color, although I have some concerns about how the finish will hold up when placed into your average jeans pocket with coins, keys, and other such common objects. Additionally, the XO also feels the tiniest bit heavier then the S9 Pro, although both of them are extremely light in weight.
If you are interested in a detailed comparison of the technical specifications of both dongles, visit this page on the Hidizs web site, scroll down about 2/3 of the page, and you'll find a chart with detailed comparisons of the two products.

I'll just highlight the fact here that both of them have a USB-C data port, along with two headphone outputs: 2.5 mm balanced, and 3.5 mm single ended. Because I ordered my Hidizs MP145 earphones with a 4.4 mm, balanced connector, I was happy that several years ago I purchased a ddHifi DJ44b adapter, that converts a 4.4 mm balanced plug into a 2.5 mm balanced plug. Problem solved!
Sources included high resolution MQA and and FLAC files from Tidal on my iPhone 14, connected using Hidiz's OTG USB-C to Lightning cable, and Tidal tracks connected to my M3 MacBook Pro via USB-C. Speaking of cables, I was disappointed with the build quality of the USB-C male-to-male cable that Hidizs supplied with the XO. The metal collar slides back and forth because of a sloppy glue job. In my experience, not typical of the build quality of Hidizs products.
So, how does everything sound?

First, the Hidizs XO is an excellent match with the Hidizs MP145 planar magnetic earphones. Listening to tracks like "Harbor Lights" by Boz Skaggs (which is a great headphone showpiece), the studio reverberation of the Fender Rhodes electric keyboard sounds cavernous, and the shaker (percussion) that travels back and forth between the right and left channels during the intro seems to move way outside the listener's head. The XO driving the MP145's also does a fine job separating instrumentals and voices. Nothing sounds smeared or blurry. Basking in the Eagles' beautiful "I Can’t Tell You Why," Timothy Schmidt's angelic tenor is front and center, while the background vocals are intimate, distinct and detailed without any harshness. And again, the sense of acoustic space is impressive; this combo sounds immersive and huge. The same goes for "Chan Chan" from Buena Vista Social Club, especially when the muted trumpet solo begins and you can really feel the acoustics of the surrounding studio.

On the low end, I often use the song "Snowbound," from Donald Fagen's album, "Kamakiriad," with its plunging, swooping six string electric bass lines, as a test of how well earphones or speakers can render low bass notes. Lesser equipment will emphasize a thumping mid-bass, blurring the pitch and obscuring the gutty, string sound of the instrument. While the combination of the MP145's and the XO clearly fattened up the low end on this track to some degree, I didn't find it offensive and the bass guitar still sounded like a bass guitar.

Up to this point, I've been describing my experiences with the XO connected to the MacBook Pro. Although the sonic qualities of this combination were similar with the XO attached to my iPhone 14, also streaming high resolution tracks from Tidal, I did run into a vexing issue. Using the up and down volume buttons on the iPhone, I found volume adjustments to be far too great with each button press. For example, the jump upward from "a little too soft" to "way too loud" just took a single press on the volume up button on the phone. Of course, every earphone and headphone will present a different load to the XO, so this volume "problem" may be specific to the earphone in question, in this case, the MP145. Volume adjustment increments were much more reasonable using my 2019 Campfire Andromeda IEM's, although I wasn't as enamored of the sonic results that this combo produced. There was something a little dull and lifeless to the presentation. Note, however, that these differences may be attributable to the Andromeda being driven by the single-ended output, since I don't have a balanced cable for them.

I'll go a bit further here and say that I wish that Hidizs had included hardware volume adjustments on the XO, and left out the flashing, multicolored LEDs on the sides of the dongle. (The pattern of flashing lights changes with each press on the "X" button on the dongle.) I suppose some people will find this little light show to be fun, but, as I said, I'd rather have hardware volume adjustment. This, by the way, is why I just placed an order for the recently released Hidizs S8 Robin DAC/amp, which does have a volume knob. I hope to review that unit when I receive it.

In the end, paired with the right earphones the Hidizs XO is a great sounding DAC/amplifier worthy of your consideration, especially when matched with the Hidizs MP145's. If you can live without hardware volume adjustment, it's worth checking out.

Introduction​

Hidizs is very popular in the Chi-Fi industry and they have been experiencing a very nice period thanks to their positive reviews on the MP145, MS1 Galaxy and other IEMs in their lineup. Not only that, they have also received some praise for their dongle DACs, and in this review I am going to cover the Hidizs XO.

Disclaimer: the Hidizs XO was sent to me by Hidizs free of charge after being selected for the “Hidizs Product Feedback Insights Program”. This review represents my personal opinion on the set and it is by no means a promotional or paid content.
At the time of the review, the Hidizs XO was on sale for around 59$ at Hidizs’s official webshop.
I wanna thank Hidizs for this opportunity as I get the chance to try one of their products and give my honest feedback that will hopefully be helpful for the brand and the community.

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Technical Specifications​

• Size → 55mm * 24.5mm * 9.35mm
• DAC Chip → ESS SABRE ES9219C x 2
• Compatibility → MQA up to 16X (requires software support, recommended to use HiBy Music, DSD (Native DSD64/128/256), PCM (up to 384kHz/32bit)
• Output type → single ended 3.5mm jack, balanced 2.5mm jack
• Frequency Response → PO(3.5): 20Hz-40kHz (±0.12dB) / BAL(2.5): 20Hz-40kHz (±0.12dB)
• THD + N → PO(3.5): 0.0015% / BAL(2.5): 0.0005%
• SNR → PO(3.5): 118dB / BAL(2.5): 119dB
• Crosstalk → PO(3.5): 76 dB / BAL(2.5): 118 dB
• Output Power → 78mW + 78mW@32Ω 3.5mm SE, 195mW+195mW@32Ω Balanced 2.5mm
• Supported systems → Android, Windows, Mac OS, iPad OS, iOS (if you have older iPhones, though, you’ll have to buy a Type-C to Lightning adapter separately)
• Net weight → 11g

Packaging​

The box is very small, it has a very simple design and contains:

• The Hidizs XO dongle
• A Type-C to Type-C cable
• A Type-C to USB-A adapter
• User manual and warranty card
• Two small “Hi-Res Audio” stickers

Design and Build Quality​

The Hidizs XO is a true beauty in its (Rose Gold, in my case) metal chassis: it’s pleasant to look at, it’s very lightweight and its size also makes it easy to fit in small IEMs’ cases.
There are two RGB LED strips on the sides, on which Hidizs spent some effort (and words), since it’s a highlighted feature on the official product page on Hidizs’ website.



There are two physical buttons on the front:

• The X button: used for changing the RGB LEDs’ colors/effects;
• The O/rounded button: used for applying a sound filter (even though the difference is almost unnoticeable) which is recognizable by the color of the outer RGB LED ring.

Performance​

Power consumption and temperature
The XO is not the most efficient dongle out there, even though this doesn’t only depend on the output or the RGB lighting (which for sure, when active, leads to higher battery drain).
One of the main issues is that the temperature increases pretty fast after some minutes of listening; this leads to more energy dispersion due to the heat, hence more power consumption and lower efficiency overall. Summer will definitely be a stressful test bench for the XO, since the operating temperatures will be much higher.
Having a dedicated gain setting option would have been optimal since one could decrease the gain with very sensitive IEMs in order to have less energy consumption and lower temperatures (hence, better efficiency with certain loads).

Sound
In terms of sound, the XO is relatively neutral with a very soft touch of warmth. It’s not the most resolving, accurate or analytical dongle DAC out there for sure, but delivers an overall nice and kinda musical sound that pairs well with almost every IEM.
Soundstage is quite expansive, detail retrieval is nice and the overall instrument separation is in line with the price range. There isn’t anything dirty going on even when very sensitive IEMs are plugged in, and the overall sound is slightly smoothened in the extreme upper and lower end in a pleasant way (hence not the most transparent/clinical or the driest I’ve heard).

Pressing the physical rounded button should slightly change the sound since there are two filter presets, but I found the two settings basically indistinguishable. Let’s say that Hidizs has put much more attention on the lighting, on the build quality and the overall appearance rather than on the sound filter.
Unfortunately, there also isn’t any button nor any combination of buttons that can be used to select a different gain setting, which is a missed opportunity.

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Some comparisons:​

Hidizs XO vs Truthear SHIO
The SHIO sounds slightly more neutral, more transparent, a little more analytical and detailed. It feels like a more capable product in terms of small nuances and it’s a bit more powerful as well. Not only that: the SHIO drains less battery (in both the gain modes through both the outputs), it doesn’t heat up like the XO and also has two gain levels, a feature that is missing on the Hidizs XO.
Build quality and lighting are of great quality on the XO, no doubt, whereas SHIO looks and feels cheaper even though its performance is slightly superior overall.

Hidizs XO vs Type-C Apple Dongle
There’s really no competition when it comes to power output, so it doesn’t make any sense to compare them under this aspect. The Apple Dongle, though, sounds very good in terms of quality, with a more linear and transparent sound compared to the XO.
The XO wins in terms of soundstage and overall detail retrieval, but it’s also slightly warmer than the Apple Dongle, hence a bit more colored and musical.
The Apple dongle has no issues with heating (it isn’t very powerful, though, so that also plays a role) and it’s basically a cable, while the Hidizs XO has a full metal chassis, RGB lighting, a balanced output (the Apple Dongle only has an unbalanced output) and looks way more premium.

Hidizs XO vs Fosi Audio DS2
The Hidizs XO is warmer, and slightly smoother in the upper end with a tad more low-end body. The DS2 is a bit brighter instead and more transparent, sounding slightly drier than Hidizs’ dongle.
In terms of power and efficiency, the DS2 can reach higher volumes and it does that without becoming very warm/hot after some minutes of listening, a thing that happens instead on the Hidizs XO and that leads to more power consumption than the Fosi DS2.
Both are built very well, they are very lightweight and portable, both feel solid in the hands and both sport an added 4.4mm jack port for the balanced output, along with the unbalanced 3.5mm port. The Hidizs XO has RGB lighting but doesn’t have any volume control buttons, and the sound filters are basically identical in terms of sound. Another important difference is the fact that the XO sports a 2.5mm balanced port, whereas the Fosi DS2 features a more common and safe 4.4mm output (2.5mm outputs aren’t very appreciated because 4.4mm connectors are generally less delicate on the long run).
The XO is not a bad dongle but the Fosi DS2 is a product with an overall higher value for money, even though they sound slightly different in terms of sound approach..

Fosi DS2 vs Hidizs XO
The Hidizs XO is warmer, and slightly smoother in the upper end with a tad more low-end body. The DS2 is a bit brighter instead and more transparent, sounding slightly drier than Hidizs’ dongle.
In terms of power and efficiency, the DS2 can reach higher volumes and it does that without becoming very warm/hot after some minutes of listening, a thing that happens instead on the Hidizs XO and that leads to more power consumption than the Fosi DS2.
Both are built very well, they are very lightweight and portable, both feel solid in the hands and both sport an added 4.4mm jack port for the balanced output, along with the unbalanced 3.5mm port. The Hidizs XO has RGB lighting but doesn’t have any volume control buttons, and the sound filters are basically identical in terms of sound. Another important difference is the fact that the XO sports a 2.5mm balanced port, whereas the Fosi DS2 features a more common and safe 4.4mm output (2.5mm outputs aren’t very appreciated because 4.4mm connectors are generally less delicate on the long run).
The XO is not a bad dongle but the Fosi DS2 is a product with an overall higher value for money, even though they sound slightly different in terms of sound approach.

A very personal take on this dongle and its target market​

I think Hidizs tried to attract two kinds of customers with a single products:

• Audiophiles/audio gear hobbyists with the balanced + unbalanced outputs and nice technical specs
• Those who are attracted by RGB lightings (i.e. gamers and similar users)

I don’t really dig when things are mixed up because the final result is usually an in-between that works just ok for both kinds of users instead of excelling.

If Hidizs wanted to make something appealing to gamers, then a very good idea would have been making a dongle with unbalanced output and TRRS support so that gamers could also microphone input, and they could also have the RGB lighting that was implemented on the XO (which is definitely cool).
If they instead wanted to aim to the hobbyists that search for the best dongles around, then they should have put a bit more effort at making the XO more efficient, with a better temperature management and less battery drain (less effort on the lighting, more effort on the overall performance).

Final Thoughts​

The Hidizs XO is among the most compact and lightweight dongles out there, enclosed in a high quality metal chassis and featuring both balanced and unbalanced outputs, which lead to a versatile and powerful source.
The RGB lighting is the icing on the cake, but it really looks like Hidizs put too much effort on a feature that drains more battery on a dongle that isn’t already very efficient. In fact, I would have understood the RGB lighting if the product was targeted to gamers, but this one aims to those who listen to music and prioritize quality, power and efficiency on the move, and the lighting doesn’t really improve the overall experience.

I still think the XO is a great device, but there are even better dongles in their price bucket and if Hidizs managed to address the few mentioned issues, this could have been an even better contender (especially considering their original listing price).

This is my first dongle to give my impressions of.
I'm approaching this from the angle of a dongle novice. I have mainly used dongles as a way of using wired iems on my phone and as such I didn't use the HIDIZS XO with any other sources.
First I'd like to thank HIDIZfor sending my the XO for evaluation, they haven't tried to influence my impressions in any way and as such these are my thoughts

Here's what HIDIZS have to say about the XO



DUAL ESS SABRE ES9219C DAC & Independent Crystal Oscillators
Get double the audio performance and the most accurate clocking for both DACs, through the synergy of the Dual ESS SABRE ES9219C DAC chips, and high-precision independent crystal oscillator, for the purest audio experience, and reproduce real music with unprecedented accuracy!Outstanding DAC parameters: 32bit/384kHz PCM, DSD256, +121dB DNR, -114dB THD+N, ultra-low power consumption, high integration, and substantially better performance than previous iterations.Remarks: The above official data is provided by ESS company.

The XO MQA Dongle is only the size of a USB and weighs only 11 grams. Contains two outputs, enough to drive mobile phones, iPads, and PCs. The output power is strong but not excessive, single-ended 78mW+78mW@32Ω / balanced 195mW+195mW@32Ω. The XO MQA Dongle perfectly balances sound quality and battery life.


The XO is not a new product and has been on the market for a couple of years I'm actually reassured by this too many products appear the disappear soon after.

The Dongle I receiveis an attractive rose gold colour, made out of aluminium. I have to say I like the RGB flashing lights a little too much. The light have many different combinations I rather like the rainbow multicolour rendition.


On initial release the dongle was $99 its now retailing for $59 which I think is a fantastic price for the functions available.

On plugging the XO into my phone (Samsung Galaxy S24Ultra) I mistakenly plugged the cable the wrong way round which meant no sound because the HIDIZS logo needs to be plugged into the phone USB-C port.
Once connected I was greated with a very ckean nuetral sound signature, organic in presentation with a rather surprising wide soundstage.
The 3.5mm se connection drive my IMR ACOUSTICS DARK Matter dual DD iems flawlessly giving a very solid bass and smooth mids the soundstage open with good layering.
Next iem I chose to pair was the Mangird Tea a very sensitive iem the delivery was so smooth and satisfying that I think this will be the pairing I will be using in future the combination was all I could wish for when on the go on public transport or out and about. The bass was dynamic with good articulation, the mids were open and sweet with the treble just about perfect for my tastes. The 3.5mm connection was so good that I don't feel the need to use the balanced connection which for me is held back by the old 2.5mm size which would mean I have to use a converter to 4.4mm as all my balanced cables are the larger termination.
The Balanced output does deliver a substantial increase in power delivery for harder to drive iems. The sound quality didn't really sound any different to the 3.5mm se to my ears.

There is full control of the XO via the Hiby app which takes the hassle out of stabbing at the tiny button in the dongle. The app is very easy to use to access the different sound signatures which do change the signature slightly attenuating the treble response. Which one you prefer will be subject to your personal preferences and the iem attached.

Compared to my limited collection of dongle the XO performed admirably easily matching the Hiby FC4 with a similar sound signature. I Discounted comparing the Cayin RU6 as its not a fair comparison due to its r2r configuration and much higher price bracket.

Conclusion
Overall I was very impressed with the HIDIZS XO for its cost and will be using it as my travel companion with my phone and the Mangird Tea for quality music enjoyment on the go.
https://www.hidizs.net/products/hid...BEHxxgQ540SQw93-4dVdw6fyn6Qacenl1xxrV95Nym8uA