100+ Head-Fier
Hidizs SD2's Review
Pros: Tiny Footprint
Balanced sound with a slight emphasis on the lows
Works well with sensitive IEM
Cons: Slightly smaller soundstage
Design (Not phone case friendly)

Hidizs is well known for their source and recently they released a banger which is very well received within the community, namely the MP145, i personally have tested and reviewed the MP145 and i definitely agree with the community. I have with me today the latest dongle from Hidizs, which is targeted at those who are new to the hobby, or audiophiles who are looking for a dongle that will take up a very small footprint.
Packaging is the usual Hidizs style of packaging, comes with a type C to A adapter, C to lightning adapter and in my opinion, very high price performance ratio and we will get to that in a while.
Build quality is solid and the unit itself does have a bit of a “mecha” kind of look to it. I would say it is unique looking, however, the design itself does have a bit of a “bug”, in the sense where i am unable to use a phone case when i want to use the SD2, other than that, everything else is fine.

  • DAC: ES9270.
  • Frequency response: 20Hz-40kHz.
  • DSD: Native DSD64/128.
  • PCM: Supports up to 384 kHz/32-bit.
  • Output option: SE 3.5mm.
  • 32Ω output power: Up to 70 mW+70 mW SE 3.5 mm.
  • Sample rate indicator:
    • Red colour: PCM 44.1-48 kHz.
    • Blue colour: PCM 88.2-384 kHz and DSD.
  • External material: Aluminium alloy + resin.
  • Transmission interface: C-type interface.
  • Supported system: Android, Windows, Mac OS, iPad OS.
  • Distortion: PO (3.5): 0.0015%.
  • Signal-to-noise ratio: PO (3.5): 118dB.
  • Separation: PO (3.5): 64dB.
  • Dimensions: 34.5×20×10mm.
  • Net weight: 6g.
Gears used for this review
  • Hidizs MS5
  • Letshuoer EJ07M
  • Aune AR5000


My review is solely based on what I hear via my equipment and I never consider my reviews to be objective in any way rather a subjective approach. Do take into consideration that everyone’s ear anatomy is not the same, so the psychoacoustics perception might be different as well, but i believe it will not stray too far

Battery Drain
  • SD2 is quite power efficient based on my test, i did not specifically measure the power draw but based on my observation
  • SD2 is plugged into my iPhone 15 at 100% battery, the volume is being set at +- 40% and i connected the Hidizs MS5 to it and let it loop through the playlist from 10pm until the next morning 7am
  • That’s about 9 hours and the battery on my iPhone 15 is at 30% when i checked the battery%, that is quite efficient in my opinion based on my observation
  • In line microphone support
  • Low power consumption
Sound Impression
Tonality wise, SD2 is slightly warm and overall quite musical to my ears. The lows are slightly elevated based on my listening impression, treble on the other hand is just right to my ears, without any peaks or over emphasis. For the asking price, it is definitely a good dongle in my opinion.

Listening Impression with the following gears
Hidizs MS5

  • Bass is punchy and tight, mid bass especially
  • Sub bass has slightly better extension
  • The highs are slightly tame and it is not as energetic as it used to sound, this pairing will please those who find MS5 too hot on the treble
  • Male vocal has slightly thicker texture and sounds fuller
  • Female vocal is full sounding as well
  • Not so much changes in terms of detail retrieval
  • Overall, a very good synergy pairing the MS5 with SD2, this is also probably it is their own in house IEM
Letshuoer EJ07M
  • A very balanced sounding IEM with a boost on the sub bass region, pairing it with the SD2 does have slightly better extension
  • Both male and female vocal also have better texture and body to it
  • Bass exhibits good control and doesn‘t sound overly boosted
  • Not much changes on the detail retrieval as well
  • Soundstage is slightly better in terms of better height,depth and width perception
  • EJ07M is not hard to drive, but SD2 is good enough if you want something that’s good sounding and convenient to have when you’re on the go. It definitely have more than enough power for efficient IEMs
Aune AR5000
  • AR5000 is a dynamic driver headphone from Aune, there’s a slight warmth in terms of tonality of AR5000, punchy bass and smooth treble, but on certain track, the note weight can be a little thin
  • Although the SD2 might seem a little under power on paper, but it is actually quite sufficient to power the AR5000 as it is not a hard to drive headphone, it somehow made the note weight a little thicker due to the slight emphasis on the lows
  • The low end is slightly elevated due to the added warmth, treble is smoother yet it doesn’t compromise in terms of resolution
Comparison (Fiio KA11)
  • Fiio KA11’s design is also minimalist in my opinion, a single short cable with DAC embedded, but when used with your phone, there will be something dangling as i mentioned earlier it’s similar to an Apple Dongle
  • The tonality of KA11 is less coloured in the sense where it’s warm but the treble does not lose its details
  • A lot more power compared to SD2


Final Thoughts
The SD2 is a good device overall in terms of sound, however, the unconventional design does have a little problem for users with a phone case, or thicker phone case. I need to remove the case or switch to a thinner case whenever I want to use the SD2, but I did think of a workaround by using it with a type c female to male adapter, which kinda defeats the intended purpose which is small footprint. At 40$ including the iOS adapter, I think for the overall sonic performance and convenience, I have no issue recommending the SD2, other than the minor quirks that I mentioned earlier, it is a good little device overall.

*A big thanks to Hidizs for sending this over for the purpose of this review. I thank them for their support as always

Head over to their official webstore if you are interested in getting one:

Hidizs SD2 Official Webstore - Non Affiliated

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500+ Head-Fier
Hidizs SD2 Review
Pros: -Price to performance
-Build Quality
-Design (may also be a con)
-Pretty good output for sensitive iems @ such a low cost (may be a con to some)
-Balanced neutral sound is great for the price
-Very clean and resolving
-Won't drain your phone battery too quick
-Nice dynamic presentation
-Pocket friendly
Cons: -Design (may also be a pro)
-Only offered in 3.5 single ended
-No more cons with this price to performance
Hidizs SD2 Review
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Hidizs SD2

Hello audio lovers, I have with me today a fine little dongle dac from the audio brand Hidizs named the Hidizs SD2. I am always looking forward to any Hidizs release, as Hidizs is always bringing something new to the table. Just recently I reviewed the Hidizs S9 Pro Plus (S9 Pro Plus Review) and gave it very high marks for its solid build, sleek and slick design and wonderful sound. So, I was thrilled to learn that Hidizs was trying to tackle a sort-of untapped area of the market. The SD2 is a tiny device constructed at a 45-degree angle that connects directly to your mobile phone, tablet or to your computer etc. through the type-c port. Not many devices take on this form, and if they do, they don't have 70mW of output and they don't have such a high quality dac chip and on, and on. Of course, Hidizs was going to outfit the SD2 with some very good tech and abilities. Nothing is ever just… Vanilla, with this company.


In top of the Hidizs S9 Pro Plus, I've also reviewed a number of earphones from Hidizs. I reviewed the Hidizs MS5 (MS5 Review), the Hidizs MS3 (MS3 Review), Hidizs MS1 Galaxy (MS1 Review) as well as the wonderful Hidizs MP145 (MP145 Review). I felt that none of these iems were misses. Each one is well thought out, with its own personality and flavor. Each set has a unique design and each stakes a claim in their respective price points. Every brand hits a snag every once in a while, but I haven't really seen that yet from Hidizs over the course of the last couple years. With all that said I'm happy to review the Hidizs SD2, let's give it a look…

Non-Affiliated Purchasing Links:

-Retail Price: $39.99
Special Price: $31.99 (Limited to 200 units)
((5% exclusive discount code: CHRIS5OFF))
Purchase here: Hidizs.net

[Amazon Link] (20% discount code: CHRISLOVESD2)
Purchase here: Amazon

Gear used for testing

-Hidizs MS3
-Hidizs MP145
-Celest Phoenixcall
-Simgot EA500LM

Hidizs SD2 Review Pic (34).JPG

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Unboxing / Build / Design / Internals


Not much to report here. You get a small black box that when opened reveals the Hidizs SD2 in all its glory. Apart from that Hidizs added a usb-c to usb-a adapter. They also kindly added in a usb-c to lightning short cable for older IOS users. Not much more to add folks. As expected.

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Build Quality

This is an area that surprised me. Very light, coming in at only 6 grams the SD2 will not weigh down your usb-c port in our device. Let's just get that worry off the table. Also, in no way was I expecting an all-aluminum body, but that's exactly what the SD2 has. Hidizs also went with a hard plastic trim around the SD2. It is very well built and sturdy. The male usb-c is plenty long enough to fit in most phone cases and so you shouldn't be burdened by a device that cannot even plug into your phone. The 3.5 single ended female port sits at a 45-degree angle from your phone. I didn't know how nice this was until I used it. Hidizs did a nice job here. You'll notice an indicator light which tells you some info that I'll explain later. Honestly, there isn't much else to say. It's built like a brick folks. Very nice Hidizs.

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Now, the design has been an area of much concern. I can't say that I didn't have the same concerns either. Granted those concerns were gone once I started using SD2. At any rate, the SD2 is simply a small square brick that plugs into your device. It kind of hangs there and the fear is that if hit the right way could destroy your phone's usb-c port. This is a legitimate concern depending on how you use the SD2. What I do is attach the SD2 to my phone and then put my phone in my front pocket upside down. I never even had a slight issue folks. It sits in my front pocket perfectly. Nothing snags it, nothing came close to breaking it either. Anyway, the SD2 has a futuristic look to it as both sides have an almost sci-fi theme going on. It's a cool look. Also, it comes in three different colorways, Black, White, & Gray. Obviously, mine is the black version. It's a dope looking little device. I know it won't be everyone's cup o’ tea, but I can dig it.


Moving onto the inside of the Hidizs SD2 is where things begin to get interesting. Hidizs used an ESS9270 dac chip which I come to find out is a very well talented chip. It has fantastic compatibility as users of Windows, IOS, Android and Harmony OS users can enjoy this little guy. The SD2 can achieve up to 32bit / 384khz PCM and DSD 128. This chip has an inbuilt Sabre amplifier which can get you up to 70mW @32ohms of output power through the 3.5 single ended jack. It has a THD+N 0.0015%, an SNR (signal-to-noise ratio) of 118 db's, and Crosstalk separation at roughly 64dbs. It is promoted to have a 20hz to 40khz Ultra-wide frequency range. It's able to support many different audio apps sound effects and EQ. This chip is actually equipped with a patented 32bit Hyperstream II Quad DacTM. That all said, another nice thing is that this device has the functionality to bypass Androids SRC integrated audio processing which can assure you that you are actually getting bit perfect audio quality. Not that we haven't seen these specs before because we certainly have. However, at this price it is not the norm my friends. I am overly satisfied with this little dongle dac and what Hidizs chose to use for its chip.
Revolutionary Multi-Purpose HiFi Audio DAC & Amplifier

Introducing the Hidizs SD2, a versatile HiFi Dongle DAC Type-C to 3.5mm Adapter equipped with the independent ES9270 chip.Supporting up to 32 bit 383kHz PCM decoding and native 128 DSD decoding, it delivers powerful performance. Seamlessly decode and play lossless Hi-Res music, making it a user-friendly, simply plug-and-play gadget for music enthusiasts. -Hidizs Promotional

Hidizs SD2 Review Pic (21).jpg


I've pretty much covered everything that isn't sound related. I would say the best features of the Hidizs SD2 is the angle of the 3.5 port, the good output power for such an inexpensive dongle dac. Having up to 70mW is more than enough for sensitive iems to bring them to good fidelity. I was even able to drive the Hidizs MP145. More on that in a bit. The SD2 also gives the user the ability to use a microphone if your cable has one. I never used this and so I cannot speak on it but the SD2 gives full controls. Hidizs also states that any mic attached can convert the sound to hi-res audio. Another nice feature is the sample light indicator which will inform you of the sample rate of the files you are listening to. Red color means PCM 44.1-48kHz and the blue color shows PCM 88.2-384kHz & DSD128. I've already spoken on the SRC bypassing which is fantastic. The specs are very good across the board. Again, not stuff we haven't seen before. But also again… not at this price.

In-line Control and HD Microphone Support

The Hidizs SD2 not only supports in-line control but also features a high-definition microphone. Plugging it in enables SD2 to convert microphone audio streams to 24-bit, 48 kHz, ensuring clear voice transmission. It serves as an essential portable mini audio decoding device, enhancing audio experiences and delivering Hi-Res music in various usage scenarios. Hidizs Promotional


I'll be pretty quick but the Hidizs SD2 is basically created to drive sensitive iems or headphones. No you aren't going to be able to drive less sensitive headphones and iems either. However, just about every iem that I own was easily driven with the SD2. I should also add that I had some decent headroom too depending on the set. Heck, I even drove Hidizs own Hidizs MP145 to good fidelity. Obviously, the MP145 does like a bit more juice to bring it to its potential but it sounded great with good dynamic range and macro-dynamics with the SD2 over 3.5 single ended. As you saw, the grmear I used was the Hidizs MS3, Hidizs MP145, Celest Phoenixcall and the Simgot EA500LM. Whay did I choose these sets you ask? Well, for one I wasn't going to exclude Hidizs iems and honestly, I just love the sound of the Phoenixcall and the EA500LM attached to the SD2. They are really great pairings. At the end of the day, the SD2 is able to drive comfortably most any iem with relative ease. Maybe some planars and sets like the Final E4000/E5000 will be a tougher thing to drive, but apart from those I think you'd be okay with whatever iem you own.

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Sound Impressions

I'll be pretty short here as there is only so much one could say about the sound quality. The Hidizs SD2 comes across warmish-neutral with a very clean response. Folks, this really surprised me. I don't know what I was expecting but I wasn't expecting something as refined. What you have is a very balanced, almost linear sound across the mix without any real color doctoring your iems. I don't hear any one area claiming dominance over the frequency to my ears. I hear a more organic quality to the timbre (depending on your iems/headphones) which is less colored than other dongle dacs. It's a natural sound in this way. Like I said, maybe slightly north of neutral as there is a very slight warmth which to me sounds very realistic and great for the price. Also, this is a smooth sounding dongle dac which has far less of an abrasive note edge. I hear no glare or shout added to my iems and I don't hear added sibilance.

Bass Region

The bass region comes across a hair north of neutral adding only a slight shade of warmth to the sound but not overly emphasized. It is still in good balance with the midrange and treble. This device will not add to the quantity of any iem (at least not that I noticed) but it's got a nice transient swiftness and short decay which comes across tight, punchy and realistic.


The midrange is another area that has nice transients. Snappy, controlled yet doesn't come across dry. I heard no real difference in note weight for any of my iems but if I had to comment on it I'd say the SD2 has a lean profile with very good presence against the rest of the frequency. The midrange has very nice clarity too. I noticed the SD2 will not cast any veil across the mix or congested the sound field at all. The SD2 will help a warmer and thicker sounding set to come across slightly cleaner, tighter and less veiled in this area, to a degree. The midrange has a more forward presence with good dynamics and a nicely technical replay as well. Yet just the same, the SD2 has a musical quality to it too. The midrange has an openness to it (depending on your iems/headphones) which can evoke a sense of air to the sound.

Treble Region

Listening to the Hidizs SD2 and using the Celest Phoenixcall I never felt the treble was any more emphasized. Instead, it came across snappy, with nice bite and decent extension. Obviously the SD2 cannot compete with much more expensive dongle dacs etc. But I still find the treble resolving to a degree. Well, as much as one can tell. It isn't the easiest thing discerning sound Differences between source devices. However, the SD2 is nice. I never hear anything too sharp in the treble, and just the same I also wouldn't call it relaxed or reserved. I think the balance across the mix holds true in the treble region and so one could say that it's a good part to a good whole.

Hidizs SD2 Review Pic (11).jpg


The soundstage seems to be pretty wide. As far as I can tell. There is most certainly an open feeling to my music. That's without question. In no way do I hear my iems sounding more congested. It isn't stuffy either, not in the slightest. Hidizs did a nice job of making sure there was adequate separation giving a sense of air between instruments and vocals. Again, as far as I can tell. Obviously, your iems and headphones will affect the sound as well so keep that in mind when I'm explaining the SD2. So the stage is open & wide with good spatiality for such a low cost. Imaging seems to help rather than hinder my iems ability to properly lay out a psycho-acoustically rendered stage. Also, I wouldn't call the SD2 a detail oriented dongle dac, but in the same breath I find the SD2 is actually pretty well detailed. Especially paired with a more detail oriented iem or headphone. Honestly I am very impressed folks. Really the SD2 does a whole lot better than I would've ever thought. Very nice.

Hidizs SD2 Review Pic (35).JPG

Is it worth the asking price?

This is one of the easiest questions to answer. Absolutely the Hidizs SD2 is worth every penny of the price that Hidizs is asking. One thing which jumps out at you when spending time with the SD2 is the sound value for the money. Truly for the simple cost of Mcdonalds for four you can own a truly hi-res listening experience that can fit in your pocket with relative ease. I really mean it that I take this little guy with me all over the place. It is just so convenient and simple, all the while the SD2 is also more complex when you look at all the features that are on offer. To be 100% honest, the SD2 is a no-brainer if this type of device makes sense for your life. Absolutely the Hidizs SD2 is worth every penny.

Hidizs SD2 Review Pic (47).JPG


I want to thank Hidizs for providing the Hidizs SD2 for a full review and feature at mobileaudiophile.com. It is alway an honor to check out the audio devices from this brand. Ya know, I waited a little while for the hype dust to settle to actually publish this review. This enabled me to take my time and really get a feel for this little device. My takeaway is this; There really isnt another device out there which can do what the SD2 can do, sound as good as it does and cost this little. This is an easy rec from me folks. So, thanks again to the awesome people of Hidizs Audio and I do hope this review has helped you to make a purchasing decision.

Other Perspectives

Please don't simply take my word for it. Take some time and read and watch other reviews as it’ll help you get a good understanding of the SD2 from many other perspectives. Not everyone has the same likes & dislikes, hearing abilities, and many other variables that can dictate how each person hears their music. This ultimately can lead to slightly different thoughts. So, please check some others out. With that, I think I’m done. Please take good care, stay as safe as possible and always…God Bless!

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mars chan
mars chan
Nice review :slight_smile:


New Head-Fier
Hidizs Sd2 (An affordable sound game changer)
Pros: ~ Very durable and quite compact in size
~ warm & engaging Sounding device
~ Good power output from this form factor (70mw@32Ω)
~ Battery consumption rate was quite low
~ Good technicalities are offered for the price
~ Low background noise floor
Cons: ~ Absence of physical volume control button
~ Only suitable for IEMs (Not for hard to drive)
~ Airy extension of the treble is somewhat lacking
~ Dynamic punch was a bit thin
~ not very suitable for neutral lovers
~ design seems a bit cheap (subjective)
★ Introduction :-

has been launching their audio gear for a long time in the market. I believe that they've managed to maintain a fairly strong position in the affordable price category. They almost all dac amp and dap are basically Ess based . But some of these dac amps like S9 pro red copper and S9 pro plus Martha have a good reputation. Sd2 dongle is their new budget friendly offering with Ess dac chip is used in this device. I'll try to highlight all aspects of the device in my review.



# Disclaimer :-

At the beginning of the review I would like to thank Hidizs for sending me the Sd2 dongle. I've no financial agreement with Hidizs for this review, so my opinion is completely personal.

★ Box content at a glance :-

The packaging of the Sd2 dongle was quite satisfactory because the necessary accessories are available out of the box so there is no need to buy anything extra.

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1. Sd2 dongle DAC x1

2. Type-C to lightning cable x1

3. USB A to C adapter x1

4. User Manual x1 & Warranty card x1

★ Specifications :-

: 34.5×20×10mm

Dac section : ES9270

Port type : 3.5mm Single-End

Input interface : USB - Type C

Frequency response : 20Hz-40kHz

Supports : PCM(32 Bit/384kHz) and
Native DSD 64/128

SNR : 118dB (SE)

Separation: PO (SE) 64dB

Output Power : 70mw@32Ω (SE)

Harmonic Distortion THD+N : (@32Ω)

Output level : SE - 2Vrms (max)

★ Design & Build Quality :-

The construction material of the Sd2 dongle is made of plastic composite , but this plastic build looks a bit cheap when held in the hand. But its side frame has been given a very nice finishing and hidizs branding on both sides along with a small led indicator which basically lights up in different colors based on the sample rate, but the interesting thing is that the device is very compact in size so it fits very well with the type c port of the phone and can be kept in the pocket when connected to the phone. It is advised to use it carefully while traveling or there is possibility of breaking the type c port of the phone.

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★ IEMs Used :-

~ Simgot EA1000

~ Hidizs MP145

~ Dunu Kima Classic

~ Hidizs MS1 Galaxy

~ Qoa Gimlet

~ Simgot Ew100p

★ Sound Aspect :-

Sd2 is basically warm sounding dongle dac. Yes, exactly! The warm sound signature of the Sd2 dongle DAC can complement neutral or bright IEMs nicely, providing a balanced sound performance. However, it may not deliver optimal performance with headphones due to its limited driving capability. The IEMs that I've driven this dongle have shown good performance, even without having to worry about the power output, it has been able to drive all of them with full potential. The thing that was most noticeable after plugging the earphone into the device was the sound stage and separation. It was able to deliver each musical note with a fair amount of weight without any notes sitting on top of the others, But it doesn't overpower the instruments and doesn't feel dull. That's why sound quality seems to be intact.But its sound has a lot of fun factor, basically it provides bass boosted sound where texture is lacking i.e. increases the bass thump more. However, this was more noticeable in the case of bass heavy tracks, where there was a lot of excess but lack of quality.
The mids of Sd2 are usually quite clean & detailed and seem a bit forward, but here I noticed a tendency to make the body of the mids a little thin in the presentation of both male and female vocals. I believe they will be unhappy if given priority to mids.
Its treble section seems to strike a balance between cleanliness and aggression, but the absence of sparkle can be a drawback for those who prefer a more vibrant treble experience. It caters well to treble sensitive people but may not be to everyone's taste.
The biggest strength of the device would be its technicalities which make it quite admirable at this price. Its staging was wide and at the same time the depth was very good also imaging was excellent because it can accurately portray the motion nature of each instrument and even small micro and macro details without any problem. So those who are gamers, they'll be more benifited from here undoubtedly.Only the issue of dynamics seems to be a shortcoming. If it was a bit thicker, then a fuller bodied sound would have been obtained. In one word, the height and weight of the notes of the sound can be expressed very well.

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★ Comparison :-

~ Tanchjim space lite
(45$) vs Hidizs Sd2 (40$)~

The Space Lite offers a balanced and neutural sound signature with excellent clarity and detail retrieval. The bass is tight and well-controlled, providing a solid foundation without overpowering the mids and highs. The mids are smooth and articulate, rendering vocals and instruments with accuracy and realism. The highs are crisp and extended, adding sparkle and air to the overall sound With the ability to create an excellent sound stage. However, I noticed some weakness in the imaging capability and micro details seemed a bit weak. On the other hand, Sd2 provides a balanced blend of bass emphasis and good treble extension, However, Sd2's imaging was precise with the presence of descent micro details which would put it a step ahead of tanchjim space lite,Although power output is higher than sd2 (98mw@32Ω) but if someone prefers almost neutral tonality and gives more priority to mids, bass and treble are almost on point then space lite is for them. The Sd2 is an ideal choice for those who like fun and engaging, bass heavy sound signature.

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★ Conclusion :-

The dongle dac market is currently very competitive. Most of the chifi brands that have popular off-the-shelf DAC chips are using their own philosophy to bring good dongles to the market. Hidizs is also on their list. Sd2 basically ess based dac, its sound is not sharp or aggressive like ess house sound, sound wise it has given warmish & musical tonality at the same time compact size has made its usability easier. Sd2 will be an excellent option for those who are looking for a good warm sounding dongle dac at an affordable price and those who give importance to portability more, It will satisfy them well.


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I've provided the purchase link below for your convenience👇👇

Hidizs website (link is not affiliated)


Amazon store
(link is not affiliated)


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Md Ismail Hossain
I'm itching to try this one


New Head-Fier
Small But Powerful DAC/AMP - the Hidizs SD2 Mini Review from a Casual User
Pros: + SD2 provided clearer, louder audio compared to my cheap dongle.
+ Detailed sound with distinct instrument separation
+ Small and portable form factor, impressive audio quality with minor drawbacks.
+ Just 39.99 USD, price to performance is excellent
Cons: - Overpowering bass in bass-heavy tracks
- Sharp frequencies noticeable in some instances
- Audio during gaming sessions sometimes painful
- Having the SD2 directly plugged into the phone port while doing exercises, running, etc may damage USB-C port
- Device tends to warm up after prolonged use, uncomfortable if in pocket.
Here’s my review of the Hidizs SD2 DAC/Amp but there’s a catch: I'm not deeply entrenched in the audio hobby, and I don’t know most of the numbers and technical jargon that are usually mentioned when it comes to audio devices. So my goal here is to review this from a casual user’s standpoint.

Tested on:
  • PC
  • Mi pad 5
  • Xiaomi 13T
Tested with:
  • Truthear Hola IEMS
  • Phillips SHP9500 headphones
In the box you get:
  • The SD2 device itself
    • Compact plastic design with metallic accents.
    • Futuristic faceplate with indicator light.
    • 45-degree angle audio jack to reduce USB-C strain.
  • USB-C to USB-A adapter
  • Lightning to USB-C cable
  • Documentation.
With all that said, the SD2 offers a drastic improvement in audio quality for casual audio enjoyers who don’t have a mobile DAC.
And while I’m not a fan of its looks, the price to performance makes this a must-buy. Especially since after all that testing, my dongle stopped working.
While most of this is based on my preferences, I hope you found this review useful.

Good luck!

PS: I made a video review if you want to watch that as well:


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New Head-Fier
Pros: Sound
Build quality
Cons: No 4,4mm balanced output.

Hidizs SD2​


Hidizs SD2
instagram link:

The Hidizs brand is quite an interesting manufacturer of really good and well-priced audio equipment. Initially, they showed their capabilities by creating several successful players and headphones. To be honest, so far I have heard more than I have actually had the opportunity to test when it comes to this brand’s products. Fortunately, this has changed and I hope that I will be able to check out many more interesting designs of the hidizs brand. SD2 is their latest proposal from the group of headphone dongles. It has a very unusual design and interesting specifications. Although the dongle market is currently extremely saturated and there are quite a number of competing models, I think that hidizs followed its own path when designing the sd2 model. Offering us a completely different approach to the topic not only in bold design, but also in well-thought-out styling. In my review, I decided to focus primarily on what SD2 offers and why it stands out on the market. So I invite you to read my observations.

Unboxing and accessories.
Unfortunately, as of the date of writing this review, SD2 has not been released yet, so I don’t know its price, but I can guess that, as in the case of other hidizs products, SD2 will be very well priced. The SD2 comes to us in a small cardboard box. We have quite a lot of accessories inside. Therefore, apart from our device and documentation, we will find a USB C to USB adapter and something that I particularly liked – a Lightning to USB C adapter in the form of a short cable. The dongle itself is somewhat unusual because it deviates from conventional shapes and is an irregular, angular shape. Although it resembles a spaceship in some ways, it is very convenient to use. The body is completely made of thick plastic, which additionally increases the durability and safety when carrying in a case with headphones. The parameters are quite good, we have a DAC system from ESS based on the ES9270 chip and 70mW of power per channel at a load of 32Ohm.

Well, first of all, I can say that if someone blindfolded me and told me that it costs 100USD, I would totally believe it after listening to it!

BAS: The lows in the SD2 are really nice, with complete neutrality and naturalness in the low range. A clean and noise-free background provides a truly excellent sound experience even with very sensitive headphones. The low tones are not overly emphasized, instead they naturally reflect the character of the headphones. The low tones are present in exactly the amount I can expect from a DAC/AMPA, which is to accompany me every day as an “interface to the phone”. I’m glad that hidizs didn’t go for a very bass tuning.

Musical midrange: Vocals and instruments embedded in this range are, like bass, very natural and neutral. The SD2 is a product with a mature and balanced tuning that can really be heard. Vocals remain at some distance as the SD2 produces quite a good soundstage with nice depth and adequate width. The vocalists’ voices remain virtually unchanged and are presented as on the original recordings. Instruments retain the right amount of air and good separation.

Treble: Higher sounds retain clarity and purity. It is still a linear and neutral sound, but care was taken to adequately extend the treble. The instruments sound lively and look really good. The amount of detail in the sound and information we can hear is at a very good level. At the same time, the high bands are not excessively sharp and represent an excellent technical level. The highs are quite a strong point of the SD2 and are well implemented.

Technical layer and imaging:
Technically, DS2 is a very strong competitor, it can show a solid level and in fact in this aspect it is the biggest surprise. I did not expect such a good technical level in equipment so small and inconspicuous.
There is relatively little power, at least on paper. In practice, I had no problem driving either pair of IEMs.

Hidizs SD2 VS Fiio KA11 (USD 29.99)

SD2 is a more neutral tuning, aimed at as little interference in the sound as possible. KA11, on the other hand, is slightly warmer, but still close to neutral. The KA11 has more power, but the SD2 still has enough power for most in-ear headphones and provides less noise with very sensitive headphones. Personally, I love both dongles, the KA11 is a great and ultra-convenient option, while the SD2 sounds up to par with the references.

Hidizs SD2 VS ddHIFI vs tc35pro (65USD)
The TC25pro is an excellent adapter that I really liked. The SD2 provides a more neutral sound, while the tc35pro is more musical and somewhat engaging, but therefore has more of an impact on the signature of our headphones. Therefore, everything depends on our expectations because both devices are really great.

Hidizs SD2 VS ddHIFI vs xDuoo link v2 (59USD)
This comparison is interesting because lnk v2 is an even more technical and cool device. SD2 has a more natural and pleasant signature and, above all, is much more compact in terms of external structure. The SD2 produces a fuller sound, while the link v2 from XDuoo focuses on a more technical presentation. Which one is better depends on our preferences, I personally like both devices.

Hidizs never ceases to surprise with the form of its projects. SD2 looks very original and although it makes an inconspicuous impression, it surprises from the very first moments with its durability and resistance to falls and other such obstacles. What is most impressive, however, is the excellent, neutral and even sound with a great sound stage and an excellent technical layer for its category. This is a very interesting dongle that can successfully replace many other audio devices. I secretly hope that hidizs will present us a balanced version of this project or maybe develop another project with a similar tuning. Generally, despite the unconventional design, the quality of workmanship is at a very high level, and hidizs surprised me with an incredibly good approach to tuning and the very attractive sound this device offers. Despite the lack of physical buttons or physical volume control, the SD2 offers compact dimensions and pure, beautiful sound. All this makes me think this model is successful and interesting. I can certainly recommend it, it works very well in everyday use.
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1000+ Head-Fier
Mecha Dongle
Pros: Design that blends in very well with smartphones.
- Good power level for its size. Performance is as specified.
- Sound clear, energetic, vivid, transparent.
- Very well executed bass.
- Very good level of detail, resolution, plus wide scene, separated and distanced elements.
- Very low weight.
- Versatility: includes in-line control and is HD microphone compatible.
- Lightning to Type-C cable as accessory.
Cons: It gets a little warm when power is demanded.

Hidizs has brought a new small dongle to the market. It is true that they have several, and some small ones like the S3. But it seems that they are still looking for a more appropriate design for use in conjunction with the smartphone. I'm the first to think that having an extra cable hanging from my phone can be a nuisance. But how about creating a much more integrable design? I think that could have been a starting point for Hidizs' new product. The SD2 is a small, irregular pentagon-shaped dongle with a USB Type-C male connection and a 3.5mm SE headphone output. It uses the ES9270 DAC that supports up to 32-bit/384 kHz PCM and DSD128. It also supports in-line control and HD microphone. It has a sample rate indicator light and, of course, high-resolution audio transmission thanks to its Hi-Res Audio certification. The scope of its use is very versatile and it is useful on smartphones, laptops, PCs, tablets and game consoles. It has a power of 70mW for 32Ω. And it is compatible with Windows, Android, iOS and Harmony OS. Let's see what this new little device is capable of in the following review.

Hidizs SD2 01_r.jpgHidizs SD2 02_r.jpg


  • DAC: ES9270.
  • Frequency response: 20Hz-40kHz.
  • DSD: Native DSD64/128.
  • PCM: Supports up to 384 kHz/32-bit.
  • Output option: SE 3.5mm.
  • 32Ω output power: Up to 70 mW+70 mW SE 3.5 mm.
  • Sample rate indicator:
    • Red colour: PCM 44.1-48 kHz.
    • Blue colour: PCM 88.2-384 kHz and DSD.
  • External material: Aluminium alloy + resin.
  • Transmission interface: C-type interface.
  • Supported system: Android, Windows, Mac OS, iPad OS.
  • Distortion: PO (3.5): 0.0015%.
  • Signal-to-noise ratio: PO (3.5): 118dB.
  • Separation: PO (3.5): 64dB.
  • Dimensions: 34.5×20×10mm.
  • Net weight: 6g.

Hidizs SD2 03_r.jpgHidizs SD2 04_r.jpg


The Hidizs SD2 comes in a small black box whose dimensions are 83x83x27mm. There is a realistic photo in the centre of the top face. The brand logo is on the bottom right. On the bottom left are the logos of Sabre, DSD and Hi-Res Audio. At the top right is the model name and a product description. On the back side are the specifications in several languages, as well as the branding. The Hidizs logo appears on the sides of the box. After lifting the lid, the SD2 is encased in a thick black foam base. There is a cloth strap to remove the product, as well as the protective layer. Underneath are the rest of the accessories. In summary, the contents are as follows:

  • The Hidizs SD2.
  • A Type-C to USB-A adapter.
  • One Lightning to Type-C cable.
  • One user manual.
  • One warranty card.

The presentation is very compact, matching the price of the product, almost $40. The lightning adapter cable and the quality of the small USB to type-A converter are appreciated.

Hidizs SD2 05_r.jpgHidizs SD2 06_r.jpg

Construction and Design

The SD2 has been constructed from aluminium alloy and resin, with a Mecha-style appearance. Its dimensions are 34.5×20×10mm and its weight is only 6g. It is an irregular pentagonal tablet, with rounded corners. On the long side is the USB Type-C male connector and on the opposite side is the 3.5mm SE headphone output. The headphone output is diagonally aligned with one side of the SD2 and is covered with gold-plated metal. It is available in three colours, black, grey and white. On my black unit the brand lettering is red. There is a small LED indicator and some red dots. The faces are not smooth and have almost concentric shapes in threes, reminiscent of the shape of the dongle itself. The edges are smooth. The USB Type-C male connection is long and projects over the surface of the edge. The design is very compact and despite its irregular shape, it fits very well into portable devices. The fact that it is a cordless tablet elevates it above its competition, in ergonomic valuation.
Inside is an ES9270 DAC that delivers up to 70mW for 32Ω. This chip features a patented 32-bit HyperStream®II QUAD DACTM architecture. With PCM support up to 384kHz/DSD128 and an integrated SABRE headphone amplifier, it has a distortion of 0.0015%, a signal-to-noise ratio of 118dB and a separation of 64dB.
It is certainly a differential design that is small and very useful.

Hidizs SD2 07_r.jpgHidizs SD2 08_r.jpg


The SD2 is compatible with Windows, iOS, Android, HarmonyOS and other systems. It can connect to PC's, laptops, smartphones, tablets, iPhone 15 and game consoles. Supports in-line control and HD microphones.
It can convert microphone audio streams to 24-bit, 48 kHz.

Hidizs SD2 09_r.jpgHidizs SD2 10_r.jpg


The SD2 has a sample rate indicator LED. Red indicates PCM 44.1-48 kHz. Blue indicates PCM 88.2-384 kHz and DSD.
When connected to Windows 10 or higher, it is automatically recognised both as a sound card and as a microphone. Thus it is an all-in-one device for the office, which can be used for meetings and video conferences. The SD2 supports integrated equalisers in conventional music applications.
It has a Lightning to Type-C adapter cable and a small Type-A adapter.
It doesn't go much further than any dongle, but the double addition of allowing in-line control and HD microphone makes it much more suitable for use in many more everyday settings than more music-specific ones. Certainly, for its size, performance, design and functionality, it can become a highly effective little travel companion.
When you start using it and the sound starts to flow, there is a small Fade-In.
Finally, the SD2 gets a little warm when power is demanded.

Hidizs SD2 11_r.jpg


According to the specifications the SD2 is capable of delivering 70mW at 32Ω. That implies that the voltage to give that value must be 1.5V RMS. And so it is, the little SD2 has a maximum voltage on its 3.5mm SE output of 1.5V.
On the other hand, the output impedance is very low and less than 1Ω.

Hidizs SD2 Zout.png

No load

As you can see, with no load it delivers just over 1.5V RMS. I find this to be a pretty good value for a dongle of this size.

Hidizs SD2 No Load.png

15 Ω

The round figure of 1V is almost reached. The voltage of 0.986V implies a power of 65mW and 65mA. Enough for IEMS of this impedance.

Hidizs SD2 015.png

33 Ω

The SD2 gives it all for this impedance, almost 1.5V, 68mW and 45mA for 33Ω. As specified.

Hidizs SD2 033.png

100 Ohms

Nothing is saved for 100Ω either, which means a power of 23mW and 15mA.

Hidizs SD2 100.png

Frequency Response

The SD2 is a Hi-Res device whose frequency response reaches 40kHz quite comfortably. From 20Hz to 20kHz the response is flat.
As for the frequency response produced by an IEMS, compared to my reference Burson Audio Playmate I, the SD2 is subtly more moderate from the treble onwards. The difference is minimal, though.

Hidizs SD2 FR.pngSimgot EA 1000 Hidizs SD2 vs Playmate I.png


The Hidizs SD2 boasts the Sabre ES9270 DAC. It is a small SOC, i.e. a USB audio D/A converter, with a 32-bit, 2-channel headphone amplifier. It uses the patented 32-bit HyperStream®II QUAD DAC™ architecture. And as usual with Sabre, its sound is quite precise, with a certain analytical tendency for the cutting of the notes, which are subtly abrupt, giving an account of that somewhat cooler, more marked, energetic and vibrant excited sound that characterises many chips of this brand. Actually, I've always commented that I like this kind of slightly punchy profile. The SD2 has a neutral presentation that is more explicit than soft. This makes the musicality more eloquent and intense, which is fine for day-to-day use, as well as for use as a companion when watching series, movies or playing games.
Starting with the pure tone test its behaviour is exemplary. Compared to the S9 Plus Martha, it is barely distinguishable. It is deep, well defined, with good power and volume. The bass is very dark, with a good roughness, something that gives it the ability to generate texture. It is concise and adept in complex situations. It follows unfiltered bass lines smoothly and shreds them neatly. It is true that it is not as smooth and musical as Martha, but it has a model behaviour in the lower range.
In the midrange the idiosyncrasies of the SD2 chip become more apparent. There is a certain level of energy that projects vocals and makes them more prominent, while presenting them as more isolated. Its edges are subtly more abrupt, something that makes certain nuances feel more vivid, but also subtly rougher, when compared to the S9 Plus. However, the SD2 maintains a more energetic and vibrant musicality, accentuating the sparkle and bringing a brightness to the edges that makes it more fun and subtly punchier. In this way, the outline of the notes is more discernible, slightly emancipated. The sounds are perceived as more concrete and well differentiated. The instruments are shown well separated and distanced from each other, producing a good sense of individual and closer representation. This proximity also favours a sense of accentuated dynamics.
All of the above is slightly expanded in the upper zone, generating well articulated, sharp, clear, very well defined and evident trebles. There is energy and a close presence. Although I have commented that the SD2 is somewhat cold and concise, this is not to say that it is a dongle that is totally abrupt and square in its definition. It has just enough definition to round out the notes, but with a sharper character than the S9 Plus. In this sense Sabre is still Sabre, but more polite. The SD2 comes across as very resolving at the top end and brings a subtle sharper touch, to compensate for its very slight drop-off compared to much more expensive DACs.
The very good sense of separation and distance generates a fairly wide scene. There is no sense of congestion and I could say that, in this respect, the SD2 is remarkable. The level of transparency and clarity is high, the scene is airy and the background looks dark. This is also due to an outstanding level of resolution and detail. The SD2 is capable of depicting minute details and presenting them somewhat in advance. Surprisingly, it is able to render micro detail quite well. It doesn't quite wrap air around it and clear it like much higher priced dongles. But the amount of space and the ability to isolate them without overlapping is very good for its price range. In this way, the image is effective, the positioning is effective and discernible. The elements are clearly distinguishable, the voices subtly forward, as are the solo instruments, which get a little bit of sparkle that pushes them forward. Overall, the scene is wide, quite spherical, thanks to its depth and height. It doesn't become enveloping, vaporous or gauzy, but the energy level and close presence anchors the elements in the image in a more concrete way.

Hidizs SD2 12_r.jpg


The Hidizs SD2 defies all other dongles with a compact, wick-inspired design. Its shape fits perfectly into any device with a USB Type-C connection, forming a tightly knit and seated piece. Forget about cables and dangling dongles. With the SD2, integration is seamless. Of course, the sound lives up to this design, thanks to the Sabre ES9270 DAC. Powerful enough for the vast majority of IEMS and beyond, the SD2 is capable of delivering 1.5V RMS for 32Ω. In addition, its output impedance is very low and its frequency response fairly flat. Outstanding are the level of imaging, detail, separation, clarity and transparency, as well as the low end response. Without a doubt, the Hidizs SD2 is a very versatile device, with line control, HD microphone compatibility, a very affordable price, a small design and very effective.

Hidizs SD2 13_r.jpg

Earphones and Sources Used During Analysis

  • Hidizs MP145 Golden Titanium.
  • Hidizs MS3.
  • Hidizs MS5.
  • Hidizs AP80 PRO-X Red Copper LE.
  • BQEYZ Wind.
  • Letshuoer S15.
  • Tanchjim Kara.
  • Rose Martini.
  • Rose QT9 MK2s.
  • NiceHCK F1 Pro.
  • Simgot EA1000 Fermat.
  • Xiaomi Redmi Note 8 Pro.

Hidizs SD2 14_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 SD2 15_r.jpg

Purchase Link

Hidizs SD2 16_r.jpg

You can read the full review in Spanish here

Hidizs SD2 17_r.jpg
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New Head-Fier
HIDIZS SD2 HiFi Dongle DAC Type-C to 3.5mm Adapter “Soulful music beyond time and space”
Pros: +neutral
+good soundstage
+highly detailed
+very good imaging
+very good instrument separation
+musical and non-fatiguing
+enough power to drive most IEMs
+efficient power usage
+led indicator for sample rate
+supports in-line mic for phone calls & video conferencing
+small & portable
+unit itself is sturdy
Cons: -no lcd display
-no buttons for volume, play/pause & switching tracks
-no 4.4mm balanced port
-might strain phone's usb port when used mobile
-no usb-c to lightning direct cable capability, need the included otg adapter
-looks won't win the hearts of many but will eventually grow on you
  • Independent Audio DAC Chip ES9270
  • Supports up to PCM 32Bit/384kHz
  • Supports up to DSD128
  • Integrated Design with Type-C to 3.5mm Audio Phone Jack
  • Support iPhone15 Type-C Port
  • Multi Compatible with Windows, iOS, Android, HarmonyOS, etc
  • Support Hi-Res Streaming Audio
  • New Generation Aluminum Alloy Mecha Design Adapter
  • Zero Delay in Audio & Video Games
  • Support In-line Control and HD Microphone
  • Sampling Rate Indicator Light
  • 20Hz-40kHz Ultra-wide Frequency Response Range
  • Support Multiple Music APP EQ Sound Effect Adjustment
  • Hi-Res Audio Certified
Comes in black, white and gray colors


I'd like to express my gratitude to Hidizs for providing me with their SD2 dongle DAC/amp for an honest review. This unit was sent to me as part of a review tour with my audio enthusiast group. Rest assured, all opinions expressed here are entirely my own, and I have received no financial gain for this review.


The Hidizs SD2 DAC Dongle features a unique shape compared to others on the market. It plugs directly into the USB-C port of your phone, PC, laptop, or tablet, eliminating the need for annoying dangling wires. While it lacks an LCD display to show music format and resolution, as well as physical buttons for volume and playback control, it does have a small LED light that changes colors based on the resolution of the source being played. Additionally, it only offers a 3.5mm port and does not include a 4.4mm balanced port, making it a straightforward and user-friendly device.


In terms of performance, the Hidizs SD2 exceeded my expectations. When paired with my Simgot EA500LM earphones and playing songs from my Qobuz account through my Samsung S23 Ultra, I was immediately transported to a musical fantasyland. I found myself listening to my music playlists for four hours straight, captivated by the synergy between the EA500LM and the SD2. The SD2 delivered the musical prowess that a good DAC should possess, offering a very musical and neutral sound profile that truly enhanced my listening experience.


For critical listening, I switched to my Tanchjim Zero earphones, known for their very neutral sound signature. Once again, the Hidizs SD2 did not disappoint. It demonstrated excellent technical performance, allowing me to hear every instrument used in the music while providing a soundstage and imaging that made the listening experience truly immersive.


One drawback I noticed when using the SD2 directly plugged into my phone's USB port is the potential for mechanical stress on my phone, especially when mobile. However, when used with PCs and laptops, the design is perfect, with the angled 3.5mm port positioning the earphone/headphone wire naturally toward the user.


With a suggested retail price of only $39.99 on the Hidizs website, the SD2 is an excellent value for a DAC/amp, especially for use with PCs or laptops where it can remain plugged in. Overall, I highly recommend the Hidizs SD2 for its exceptional performance, user-friendly design, and affordability.

Sound Signature: fairly neutral
Soundstage: spacious..has good depth and height
Detail: highly detailed
Imaging: superb imaging..can precisely locate where instruments and vocals are placed
Separation: good instrument separation
Dynamics: good dynamics..each tone delivered well and timbre is good
Sensitivity: enough power to drive most IEMs..didn’t need to go past the halfway mark on the volume
Fatigue: can listen to music all-day long with it
Build Quality: unit seems robust, no delicate parts that can easily be broken
Value: at only $ 39.99..you can’t go wrong with the SD2

Equipment used for evaluation:
  • Topping DX3 Pro Desktop DAC/Amp
  • Shanling UA4 DAC/Amp Dongle
  • Simgot EA500LM IEM
  • Tanchjim Zero IEM

Official Website: https://www.hidizs.net/products/hidizs-sd2-hifi-type-c-to-3-5mm-adapter-dongle-dac
Amazon Link: https://www.amazon.com/dp/B09G9YMHV5?th=1
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New Head-Fier
Hidizs SD2
Pros: • Neutral clean sound
• Compact and very light
• Powerful sound output for its size, dont let the 70mw fool you, its sounds more like 120mw, dont make the same mistake i did and please make sure your phones volume is not max when plugging and hitting play 🙂
• Wide and holographic sound.
• Balance and natural tone without sounding too warm or bright.
• Efficient. will not drain your phones battery.
Cons: • No balance 4.4 output.
• No direct Lightning plug version needs the included otg cable for ios.
• Not gonna win any beauty contest 🙂 but the shape kinda grows on me, specially when i use it with my laptop or tablet.
• Faceplate with the mecha design is not a very attractive design choice for me, they should have gone for a all metal plain surface. simple.
elegant even with the polygon shape.
Hidizs SD2 is the latest Dac Amp adaptor from Hidizs with ES9270 Dac chip and supports up to PCM 32bit/384bit and DSD128 and with an output power of 70mw at 32ohms and available only with 3.5mm no 4.4 balance version, it comes with a female type c to male lightning otg cable which allows you to use the SD2 like a regular dongle dac.


The SD2 is made out of metal frame and a plastic faceplate very compact and with a very odd polygon shape which when use on a cellphone or dap will look and feel unnatural for me but when i plug it in the side of my laptop or tablet the shape and the angle makes total sense with the cable of my iem facing me at an angle that is very convenient and doesnt get in the way.



The SD2 may not win in the looks department for me but sure wins in the sound, what it lacks in beauty makes up for it with its performance and portability, it has a neutral to a little bright tonality with good imaging and layering of voices and instruments, balance accurate bass, mids are a bit forward and emphasized with just the right amount of sparkle in treble. for its size and 35-40usd price the sd2 can out perform in sound some of my dongle dacs thats twice its size and cost.


Here is a link to my unboxing of Hidizs SD2. :gs1000smile:

mars chan

New Head-Fier
Hidizs SD2, sound evaluation, and comparisons.
Pros: + Small form factor
+ Good looking design
+ good sound quality
Cons: - Not as powerful as it should be
a5 (Copy).jpg
First of all, I'd like to thank Hidizs for providing this SD2 dongle DAC/amp for my honest thoughts and review. This unit was sent to me as part of a review tour with my audio enthusiast group, but you can rest assured that everything I say here is of my own volition. There is no financial gain on my part.

Hidizs is an audiophile company based in China that makes digital audio players, dongleDACs, and IEM earphones.
b7 (Copy).jpg

The Hidizs SD2 (40 USD) is a recently released HIFI dongleDAC with a very compact form factor ( see photos); it is fully made of metal and has a very unique design.
c9 (Copy).jpg

Before we go to the sound quality descriptions, let me tell you in advance that all the differences in sound are very small and might not be audible to some people. You can take them with a grain of salt.

The Hidizs SD2 has enough power to drive any of my IEM earphones and most of my headphones to very satisfyingly loud volume levels.

Sound Quality;

The sound stage is quite big, with good height, width, and depth. The transparency is also very good, and better than all my small dongles. The tonality is neutral.

The bass is full-bodied and powerful-sounding, but I find it to sound a little boomy and could lack bass control on some songs and IEMs. It seems to blend together the bass guitar plucks on fast songs instead of presenting them separately.

The midrange is lush, musical, and transparent; it is neither laid back nor forward.

The treble is transparent and extended.


e2 (Copy).jpg
Vs. Moondrop Dawn Pro (50 USD);

The Dawn Pro has a bigger form factor but offers more power output. The Dawn Pro has a deeper sound stage and is about equal in height and width. The Dawn Pro sounds warmer, while the SD2 is neutral. The SD2 has a little less bass control, meaning the bass is less tight and more boomy. But again, let me remind you that the differences are really small; the form factor and size become a bigger factor in your buying decision.

Vs. Moondrop Moonriver 2 (180 USD);

These two have the most similar sound of the bunch, except that the Moonriver 2 has a little elevated upper treble and a tighter and deeper bass. The sound stage size is the same as well as the transparency, but I can hear the Moonriver 2 having a darker background.

Vs. Hidizs S9 Pro Plus Martha (100 USD);

The S9 Pro Plus Martha has more transparent sound, a bigger sound stage, and more bass control. The S9 Pro Plus has the most transparent sound of the group. If you don't mind the bigger form factor and more expensive price, I recommend the Hidizs S9 Pro Plus Martha as it has better overall sound quality, but if size and price are more important to you, then get the Hidizs SD2.

Vs. Fiio KA11 (30 USD);

The Fiio KA11 is the real rival of the SD2 in this group; they were both released within a month of each other, and both are small (see photo). The KA11 is more powerful but less neutral-sounding than the SD2, as it has thicker tonality with somewhat boosted bass and treble, but again, the differences in sound quality are really small. The biggest deciding factor is the form factor. I like the Fiio KA11 for its slim and unobtrusive design, but I also like the Hidiz SD2 for being small and good-looking when connected to the phone.
f3 (Copy).jpg

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It's not perfect; the bass control could be improved, but again, the differences are really small; it's just me nitpicking, and if you consider the price, design, and form factor, The Hidizs SD2 is an easy recommendation.


Hiidzs Website : https://www.hidizs.net/products/hidizs-sd2-hifi-type-c-to-3-5mm-adapter-dongle-dac

Amazon link : https://www.amazon.com/dp/B09G9YMHV5?th=1&tag=headfi-20
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New Head-Fier
Musicality > Reference
Pros: Mic Passthrough
Good UX
Compact Size
Good Power
Cons: Sticks out of your phone
Warn-ish, bass boosted tonality (Preference thingy)
Jarring feel of unplugging the IEMs when SD2 is Plugged into your phone
This is a new Dongle DAC from Hidizs called the SD2. It’s just released at the time this video went live. This unit is provided by Hidizs as a sample unit. Although, the thoughts and opinions that are in this Review is 100% my own and I’ll try to be unbiased as possible.

This unit costs 39 dollars.

The SD2 is powered by an ES9270, it supports Native DSD64 and 128. In PCM, it supports up to 384kHz/32Bit. You can tell by the LED that are on the product. Blue for 88.2-384kHz and DSD, while the if it turns red, it is outputting in PCM Sampling Rate 44.1 to 48 kHz. I currently don’t have any DSD Files on me, and my library are mostly FLACs.

Moving on to the sound, the SD2 is tonally warmer than the TEU-99 or BTE-222. What I mean by warm is that the sound that came out from the SD2 is slightly bass boosted. It’s not as bad as if I plugged in my IEMs directly to my PC. But it’s noticeable. I personally thing this Dongle DAC works best with bright neutral-ish IEMs like the original moondrop Chu and TEA-99 from TimeEar or maybe other Earbuds too as earbuds aren’t really known to be as bassy as IEMs. I’m actually working on the TEA-99 review. But, I digress.

My pet peeve with the SD2 is that I personally prefer something that is low-profile or something with removeable cable. And, the fact that the 3.5 output is angled made the experience of unplugging IEMs without unplugging the SD2, pretty jarring. Lastly, the warm-ish tone feels like something that has a V-shaped tuning like the MS1 Galaxy, sound overly warm to my taste.


I think the SD2 is a DAC/Amp that emphasize musicality over reference. One of the true highlight of the product for me is actually the Microphone pass through. The TEU-99 doesn't support Microphone Passthrough. The accessories is nice. I think if you have a reference IEM, this could add some spice to it.

I actually did a double review, comparing this Dongle DAC to the TEU-99 from TimeEar. A rather unknown Dongle DAC outside of China. Which You can check the full review Here.


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500+ Head-Fier
HIDIZS SD2: Compact Dongle, Notable Performer
Pros: ● One of the most affordable dongles around in the market.
● Compact form factor with a mecha-inspired design.
● Inclusions of adaptors to make this dongle more versatile to use.
● LED indicator for sample rate
● Reliable ESS DAC
● Native DSD support up to DSD128
● Consuming less power drag from its host devices.
● Decently good thermal management for a compact device
● Supports almost known operating systems.
● Can deliver an acceptable amount of power output enough to drive power-demanding sets like planar IEMs.
● It delivers a balanced-neutral tonality.
● Good resolution capabilities.
Cons: ● Unusual angular placement of a headphone port might be an issue to some users.
● Probably cannot drive properly on power-demanding cans especially with a planar driver.
● Absence of volume control keys
● No MQA support for MQA lovers.
● Just a standard 3.5mm single ended jack, so not a chance on other balanced terminations on this device.

HIDIZS is one of the few audio companies out there that I really get along with. They are on the right path of success with the release of their products, the MS3, S9 Pro +: Martha and the one of the most acclaimed planar set out there, the MP145.


What I have here to feature in this review piece is their latest product, the HIDIZS SD2.This is HIDIZS’ budget-level DAC/amp dongle tailored specifically for portable audio enthusiasts who want a more compact form factor without compromising the sound quality while on the move.


The SD2's overall construction is made of aluminium alloy which is quite light and its unusual trapezoid shape has that mecha-inspired design that we are quite familiar with. It has an angular, 45° positioned 3.5mm headphone jack at the bottom part while a type-c connector is at top part in a perpendicular angle albeit a bit off-centre.


This device also has an LED indicator for sample rate just like all HIDIZS USB DAC/amp dongles but it only has 2 colour indications.

RED COLOUR - 44.1 - 48kHz PCM

BLUE COLOUR - 88.2 - 384kHz/ DSD64 - DSD128


This dongle offers a variety of adaptors, from lightning adaptor for older iPhone devices up to the USB type-a for PCs and laptops that make this dongle more versatile to almost all known modern multimedia devices. It is also noted the type-C connector will support all Android devices with said type of connector and a good news for users with the latest iPhones to enjoy apple music or any streaming services, this dongle can fully support it and it can even use its mic option and in-line control. The mic has a high definition output that can deliver a crisp and crystal clear vocal quality.



On its internal parts, HIDIZS implemented an older but reliable ESS DAC, the ES9270. This DAC has 2-stereo channels with built-in class G Sabre DAC capable of delivering a power output up to 2.0Vrms and it can support Hi-Res up to 32-bit 384KHz PCM and also, up to DSD128 on DSD or DoP. The power output of this dongle was rated to have a 70mW + 70mW at 32 ohms with an SNR of 118dB


On the software side, this device can support almost all known popular operating systems either in mobile or desktop format. And also, this device is compatible with the built-in EQ features of some popular music apps on android like UAPP, HiBy Music app and Neutron app.


On product packaging, it was packed in a small compact square box, and somehow, it offers some supporting accessories for SD2.


Here are the following contents, you can find inside of its packaging box:
  • HIDIZS SD2 Dongle
  • USB Type-C to USB Type-A adaptor
  • USB Type-C to Apple lightning adaptor
  • Paperwork like instruction manual and Q.C. stub

As a dongle with no built-in battery, this device will syphon some amount of power from its host device and its thermal handling is good as it is quite well-optimised to lessen heating. It drawn-off a minimal amount of power from my mobile devices so that I can use it for a longer listening session.


As for its sonic profile, the HIDIZS SD2 has a neutral sound with just a minimal amount of warmth to make it more a “balanced-neutral” sound.

I will pair this device on my sets with different shades of neutral sound profile like LETSHUOER EJ07M, LETSHUOER EJ09, AFUL MAGICONE, BQEYZ WINTER, HIBY CRYSTAL 6 II and LETSHUOER Cadenza 12.


Precise, punchy and lucid bass response that it is more than enough to deliver a well-balanced bass response on sets. It is quite capable of giving a rumbly sub-bass response and a slightly textured mid-bass that can adequately give an ample note on bass-focus instruments and deep male vocals like bass-baritones.


The midrange is fairly neutral, linear, transparent and clean. It has a sufficient texture and energy for vocals and instruments to sound more natural and articulate without too much colouration.

Male vocals have some density and depth on any types of voices, from baritones and countertenors. With enough energy, it gives more crisp and clarity on some female vocals like mezzo-sopranos and sopranos. On instruments, they quite sound very organic with some detail on their distinctive timbre and tone.


The treble appears to be well-balanced compared to some devices with an ESS DAC which has those “glaring” characteristics that might sound too digital. It has glosser treble response with just sufficient amount of sparkle and a moderate airy extension that won't give an exaggeration on colouration on high frequency that might be too piercing.


ESS DACS are known to be very competent in this field aspect as sound/speaker can give that spacious and roomy head room in a sonic canvas with good stereo imaging presentation that can panned out cleanly the precise location of instruments and vocals in a soundscape.

Resolution capability of this set is excellent as it is able to retrieve some information on both macro-dynamics and micro-dynamics like notation attack, note textures and vocal ends.



● This device has a circular compact design attached to a fixed cable with Type-C connector. Like all HIDIZS devices, it also has an LED indicator and an ESS DAC inside, the ES9281C. It has a MQA-support in which we can determine its unfolding mode when the LED light colour changes to a magenta.

● As for sound profile, it also has a neutral sound albeit if I compared it to SD2, its treble response is a tad bit brighter. The technical performance of this one is almost similar to the SD2 which is quite competent to deliver a perceived wide soundscape and good resolution capabilities in a clean sonic background.

It seems that HIDIZS will try to take some advantage of the current development of mobile technology that this device is aiming for. With this device, its compactness and performance at affordable and reasonable price will assure that its device will deliver a good sound quality in a compact form and will be easy to use and carry around. As its unusual design choice might be a concern to some users but I think this design choice is more doable and conducive for me as a person who is quite physically active that I was able to just insert this dongle into my mobile devices without any hassles like most dongles with detachable short cable dangling around during my brisk walking session.

Will I ever recommend this device as an alternative option? Certainly it is.

HIDIZS SD2 is now available at HIDIZS OFFICIAL STORE and also in AMAZON, check out the unaffiliated link below that I've provided.



For more HIDIZS product reviews:









DSD: Native DSD64/128
PCM: Support up to 384kHz/32Bit
OUTPUT OPTIONS: Single-ended 3.5mm
Red Color : PCM 44.1-48kHz
Blue Color: PCM 88.2-384kHz & DSD
SHELL MATERIAL: Aluminum alloy + Resin
Net weight: 6g
AUDIO PARAMETERS: Test Conditions @32Ω Load
DISTORTION: PO (3.5): 0.0015%
SNR: PO (3.5): 118dB
SEPARATION: PO (3.5): 64dB
OUTPUT POWER: Up to 70mW+70mW SE 3.5mm

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 *
Ottoman Mehter - Hucum Marsi *
Diana Damrau - Mozart: Die Zauberflöte*
Type O Negative - Black No.1 *
Felix Ayo - Vivaldi: Presto **
Three Tenors - Nessum Dorma *
Mercyful Fate - Witches' Dance *


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 send my gratitude to MS. ZOIE HELLO for providing this review unit. I truly appreciate her generosity and trust towards me and other reviewers.

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500+ Head-Fier
Hidizs SD2 – handy, small, universal USB DAC
Pros: good sound quality, led light, no battery drain, small
Cons: might be some flex in future

Small but mighty – this is the only phrase that comes to my mind after using USB type-C dongles of this kind. This time it is Hidizs SD2 – the newest USB dongle that is designed to squeeze more juice to drive headsets to the appropriate levels when compared to the integrated sound amplifiers. It is not the first take of Hidizs on dongle DACs and by this point they have quite an experience and knowledge to design tiny, yet powerful DAC&AMP. Although, there were always pros and cons of using such devices which would be described in this article.

Hidizs SD2 has been released to public only couple of days ago and the first 200 units would be sold at special prize (31,99USD).


First, specs&features:

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As seen from the specs, SD2 is compatible with all types of devices out of the box, supports PCM32bit/384kHz sampling and DSD128, as well as in-line remote and mic. Therefore, it not only brings back 3,5mm jack output to all of the devices free from it by the hand of marketing managers, but also gives the possibility to enrich sound quality and use your phone functions in the most convenient way. Hidizs also claims that the sound has zero delay what makes it possible to watch videos and play games apart from listening to music.


Box contents:

Apart from the SD2 itself, you’d get USB A -> type-C adapter and Lightning -> type C adapter which covers most of the possible variety of modern devices. If I am not wrong, this is the first time when Hidizs adds lightning adapter to the bundle and makes this device fully compatible with Apple smartphones out of the box.


Design, fit and build quality:

SD2 is really small. Much smaller than most of the USB type-C dongles available from other brands. It is only 20×34,5x10mm in physical size and designed in such a way that 3,5mm output comes out of the case at 45 degrees angle. This clever design serves two roles: type-C port side has enough surface length to press against the device and eliminate side flex and headphones output brings the jack closer to the source device, making the load shoulder even smaller. In real life, SD2 sits quite securely at place and doesn’t make me feel that it would destroy type-C port of my phone. I can’t say that such hard-type of connection is better than using a cable in-between, but the connection itself is stronger than I thought it would be. On the other hand, such connection would depend of the type of bumper or case that is used with the smartphone. If it is thick and soft – SD2 would not feel that tight.


Device in use:

SD2 is designed to work straight forward out of the box – connect it to any source like Android smartphones or tablets, Windows PC or Apple smartphones and it should be recognized by the system as USB audio device. Furthermore, such apps as HiBy Music on Android would also recognize it as bit-perfect device to bypass system audio mixers and send data directly to USB.

Common for all Hidizs devices, SD2 shows incoming audio quality with different LED colors: red for PCM 44.1-48kHz and blue for PCM 88.2-384kHz & DSD128.

While using this device there were no noticeable lag in audio while watching movies, neither there was case heating or extraordinary fast smartphone battery drain. Seems that Hidizs did a good job on optimization on internal circuits.


Sound wise, first what I was after is the capability of SD2 to handle full-sized headphones such as Audio-Technika ATH-M50 and Logitech Astro A10. First is pretty tight closed back with 50Ohms impedance, second ae the gamins ones with a mic and 32Ohms impedance. All driven from Xiaomi Redmi Note 8Pro smartphone which is not great at all on its own 3,5mm headphone output. Not great means that it feels anemic, low powered, artificial, with smeared highs and soft on mid bass when trying to drive such types of headphones… SD2 definitely nails it and is capable of driving both at much more appropriate levels, bringing the life and juice to mid bass, much better clarity of treble, together with higher volume in overall. Music starts to feel more engaging and transparent, when each instrument has its place and room. Layering and imaginary scene gets better. And all of that is apparent, no need of recurrent tries. In my opinion, SD2 is doing much better that integrated dac/amp of this particular smartphone.



It is great that we still get the possibility to have 3,5mm headphone output in almost any device despite the decision of marketing that it is no longer valid for the end-user. Denying the will of having higher audio quality on wired headphones or IEMs and forcing to be content in bluetooth boundaries is more about making more profit on more expensive devices, rather than providing the best quality or unleashing the potential. It is great that there are such product as Hidizs SD2 that bring back the possibility, functionality, compatibility, quality and passion… SD2 is one of the smallest, yet capable devices that makes wired headphones useful again, while overcoming the shortcomings of the integrated circuits.

Link to the official Hidizs store: LINK

Link to Amazon store: LINK

You can use ZMCR5OFF as 5% discount code.
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100+ Head-Fier
Hassle Free, Compact, Detailed
Pros: +VALUE
+Neutral / Transparent
+Power Consumption
+Supports Microphone
Cons: -Feels a bit Cheap Compared to Competition
-Looks (Subjective)
Hidizs SD2
$39 / $32 first 200pcs.

IMG_20240211_121628_513 Cropped.jpg
Before I even start this review, let me first say my thanks to Hidizs for sending me the SD2 in for review.
Rest assured, my review is as always 100% my own personal opinion and Hidizs has no input at all on the review.

Just in case you want to support me, you can get the Hidizs SD2 on this affiliated link below :
Discount Code / Coupon : LITTLENEZT
Amazon (Non Affiliated) : https://www.amazon.com/dp/B09G9YMHV5

Build Quality

The SD2 is made in from aluminum alloy+ resin material, it is very light weighing at only 6 gram and compact, but it only has 3.5mm port (supports microphone).
The build is fine, not the most premium feeling dongle, especially compared directly to FIIO KA11.
There is also a small LED sample rate indicator on the front of the device.
Also for the looks, its uhh.... mecha-ish, to be honest im not a fan of the looks but hey, it's subjective I guess.

Power & Battery Consumption

The SD2 is rated for 70mw @32ohm, it is decent, not the most powerful small dongle, but it is decent.
As for Its battery consumption, it is very efficient, I got 10 minutes only for 1% of my Infinix Zero 30 5G battery.

Compared to FIIO KA11 for Context.
I would like to describe the SD2 as a neutral sounding devices, not warm, and not bright either and a bit leaning to analytical type of sound.

Bass of the SD2 is neutral and the control is decent, it can displays rumble of your IEM without any problem.

One thing I noticed when I compare the SD2 to the KA11 is that, the SD2 has normal bass punch, but has deeper sub-bass rumble rather than bouncy and boomy bass colored like the KA11.

Midrange of the SD2 is also neutral / transparent, not colored in any way, at least to my ears.

It doesn't try to add more weight nor clarity so it is a pretty honest sounding device.
This thing could be a good or bad thing depending on your preference, if you want a truly honest sounding midrange then yeah it is a good thing, but for example if you want more emotion on your midrange such as extra weight, the SD2 might not be the right fit for you.

Treble of the SD2 is somewhat extended and has good definition, compared to the KA11, I noticed that SD2 offers more “complete” treble presentation. Its like everything is more extended and the layering is also more superior than KA11.


Stage is very good, its wide, wider than KA11, you can easily tell things is more expanded with the SD2 when you A - B compare it with the KA11

Imaging is good, it has around the same level of the KA11, which is a lot better than your standard smartphone audio.

Separation and Positioning is very good, thanks to the wider stage, object sounds more separated and positioning is more sharp and exact compared to the KA11 and is A LOT better than your smartphone audio.

Detail Retrieval is very good, it has good amount of micro details, a lot more detailed than the smoother type sounds of the KA11.

Don't get me wrong, the SD2 is still sounds “smooth” or probably I should say it as non fatiguing, BUT it has better texture and resolving capabilities than the KA11, probably thanks to the typical analytical sabre sound.

So, is the SD2 any good?

Yeah it is decent for its price. It offers a very compact, lightweight and a lot more detailed sound compared to your smartphone audio.
Not only that, theSD2 is also a very efficient device on its battery consumption.
The only nitpick I can give to the SD2 is that its power is just average, not powerful but not really bad either.

Thanks for reaching this far !

Just in case you're Indonesian or understand Bahasa Indonesia, you can check the video review of this dongle here

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Great review and thanks for the coupon code, littlenezt!


New Head-Fier
Hidizs SD2 - The Mecha style dongle
Pros: Quite good Build Quality
Natural, Warm - balanced sound
Led is showing the sample
All adapters you need included
Good power 70mw + 70mw
Phone calls & mic are supported
Small factor
Widely compatible
Cons: The design could be weird and uncomfy
On my "prehistoric" iMac it occasionally goes into a limited sampling mode.
No Buttons
No app
If your phone case is thick, you may not be able to connect it

I'm always grateful to Hidizs, who keeps contributing the most to my hobby. Thank you very much to Zoie for kindly sending me this Hidizs SD2 for testing and review!

I now have so many dongles that I no longer know where to put them. I don't yet know what price this product will have but I assume and hope it is a product that we can consider entry-level.

The review, as always, will be completely unbiased and uninfluenced.

I would like to remind you that I am just a person who enjoys trying out new items and listening to a lot of music; I am not an expert.

My opinions are obviously subjective.

Tech Specs:

  • Dimensions: 34.5×20×10mm
  • DAC Chip: ES9270
  • DSD: Native DSD64/128
  • PCM: Support up to 384kHz/32Bit
  • Output option: Single-ended 3.5mm
  • Sampling rate indicator: Support
  • Red Color : PCM 44.1-48kHz
  • Blue Color: PCM 88.2-384kHz & DSD
  • Shell material: Aluminum alloy + Resin
  • Transmission interface: Type-C interface
  • Supported System: Android, Windows, Mac OS, iOS
  • Net weight: 6g
  • Audio Parameters: Test Conditions @32Ω Load
  • Frequency Response: 20Hz-40kHz
  • Distortion: PO (3.5): 0.0015%
  • Signal-to-noise ratio: PO (3.5): 118 dB
  • Separation: PO (3.5): 64 dB
  • Output power: Up to 70 mW + 70 mW SE 3.5mm
  • Priced 31.99 USD on sale official site
  • Coupon code: PF5OFF

Hidizs SD2 has less elaborate packaging. We do not find the classic rigid plastic packaging but a cardboard package. However, the packaging is quite neat but what is surprising is the standard equipment of the small dongle.



Once opened inside, we find the DAC embedded, and below we find the accessories:

- USB A adapter

- Type C to lightning

- Manual + QC/warranty

Build quality/first impressions:

At first glance, I would dare say that we are faced with a slightly cheaper product than what we are used to with Hidizs. The Hidizs SD2 comes with an extremely particular "Mecha" design. The two faces appear to be made of metal, while the body is made of plastic, or, I would say, solid construction.

The design intrigues me, but at the same time, it makes me think that it could put a strain on the type C sockets. Both the shape and the angle of the headphone jack create important levers on your type C sockets. In any case, we can define it as the successor to the Hidizs S3 Pro. If it weren't for the design, it would be very difficult to distinguish them in operation.

Power & Sound:

The newcomer contains a slightly dated but still excellent chip, the ES9270, which, unlike the one mounted on the S3 Pro, produces 140 mW at 32 ohms. So this little dongle is definitely more powerful. I tested it on the 64ohm EPZ x Tipsy and they drive them at excellent levels and I don't feel any fatigue on the bass, which remains nice and full-bodied.
I also tried it with the Hidizs MS5 to see if it could surprise me even with other level IEMs. I must say that on the iMac, I only need 3 volume levels and it is impossible for me to go beyond halfway. With the addition of the 75 ohm adapter, you can reach the maximum volume; it is better to stay around 64 ohm at most.


It supports the microphone; not many have this functionality, but I must say that it is convenient if you also use it for calls, conferences, and even gaming.



I think for the most part of this hobby, the power is sufficient but now there is also the Fiio KA11 on the market.

In terms of sound, I struggle to distinguish it from the S3 Pro. Hidizs always follows that tone that is not too neutral but slightly warm. On bright IEMs, it helps to better control the treble region while maintaining excellent details. I also feel slight coloration in the midranges but I must say it was a pleasant result.

Fast Comparison:

I don't think comparing it to models with balanced output makes much sense; obviously, they perform better. So the comparison will be made with other single ended DACs.

vs Hidizs S3 Pro


Very similar, so extremely similar that it is impossible for me to say that I noticed real differences in sound. I think there is slightly more emphasis on SD2 but it could be the extra power that gives it dynamics. We have less power and a much more elegant design but the rest is the same.

vs FiiO KA11


The increased power is instantly noticeable. The KA11 requires only two volume bars, whereas the Hidizs SD2 requires three. Both have a slightly warm sound, with Hidizs taking the lead. The Fiio produces a more controlled and decisive bass. The designs are completely different, but the most traditional is probably the most comfortable. I suggest you read the entire review.

Who do I recommend this DAC to?

At the time I'm writing this review, I don't yet know the market price, but I can tell you that to compete, it must be offered at an extremely aggressive price. The FiiO KA11 has positioned itself with a very low price; the power is excellent and it cuts out all the competition. However, the Hidizs SD2 has very broad compatibility on its side, including the USB A and Lightning adapter. You can use it on any device without buying additional adapters, and the sound is still very pleasant, even if it is not suitable for overly critical listening. Regarding the shape and angle of the jack, I'm not too convinced of the design. I see it as much more comfortable to connect to a laptop well placed on a desk than to use it on a smartphone that fits in your pocket.

In any case, you can use this discount code, "PF5OFF", to get a 5% discount on various products.

Where to buy?
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Headphoneus Supremus
Pros: Generously accessorized
Compact profile, weighs only 6 g!
Good fit for desktops/laptops USB ports
Consumer-friendly fun-sounding signature
Excellent imaging and soundstage for a budget dongle
Gets warm but not hot during usage
Supports mic
Cons: May inadvertently bend USB-C ports of phones if snagged, due to unconventional design
No volume control
Single-ended only, no gain settings - not the most powerful of dongles
"Pop" sound noted when disconnecting transducers
Bass is a tinge bloated and undefined

I would like to thank Hidizs for providing this review unit.

The SD2 can be gotten here: https://www.hidizs.net/products/hidizs-sd2-hifi-type-c-to-3-5mm-adapter-dongle-dac or https://www.amazon.fr/dp/B09G9YMHV5 (no affiliate links).

SD2 5.jpg


DAC Chip:
ES9270 DAC
Dimensions: 34.5 × 20 × 10 mm
Weight: 6 g
Maximum supported bitrate: 32-bit/384kHz PCM, DSD 64/128
Output port: Single-ended 3.5mm
Output power: 70 mW + 70 mW
Frequency Response: 20 Hz - 40 kHz
Distortion: PO (3.5): 0.0015%
Signal-to-noise ratio: PO (3.5): 118 dB
Separation: PO (3.5): 64 dB
Tested at: $39.99 USD ($31.99 for first 200 units)

The SD2 is a plug-and-play device; on Windows 10 systems and above, there is no need for any additional installation of drivers. I am not an Apple ecosystem user, but the SD2 was easily recognized on various Android and Windows devices I paired it with.

Unsurprising for a budget dongle, the SD2 does not have any app, DAC filters or built-in EQ options. It supports microphones though.


SD2 3.jpg

Other than the dongle, included are:
- Type-C to USB-A adapter
- Lightning to type-C cable

SD2 2.jpg

Surprisingly, there is no type-C to type-C cable to extend the reach of this dongle, but for a budget DAC/AMP, the accessories are nevertheless quite generous. I've definitely have encountered way more expensive dongles which omitted even the USB-A adapter. Also, our Apple-using brethren should be happy with the inclusion of a Lightning adapter.


SD2 7.jpg

In a sea of rectangular or cylindrical dongles, the SD2 certainly stands out with its asymmetrical pentagonal shape, coupled with a unique Mecha-style motif etched on the surface. The dongle itself is fashioned from aluminum alloy with an external resin fuselage.

The SD2 is for sure, one of the smaller dongles, weighing a mere 6 g, and measuring 34.5 × 20 × 10 mm. During ordering, consumers can choose amongst a black, white or grey hued chassis.

SD2 4.jpg

On one side, we have a gold-plated 3.5 mm terminal.

SD2 1.jpg

The opposite side houses the USB-C port.

The SD2 does not have any volume controller - thus, users will need to adjust the volume at the proximal source - and it has no screen.

This dongle does have a LED light, which will switch between red and blue, depending on file bitrate played:
  • Red Color: PCM 44.1 - 48kHz
  • Blue Color: PCM 88.2 - 384kHz & DSD

The SD2 is a great match for laptops and PCs, due to the small profile that functions similar to a thumb drive. It doesn't dangle around unlike other elongated dongles which have cables flailing around.

SD 2 10.jpg

However, the SD2 may be an awkward proposition for phones, especially if placed in tight pockets or small bags. I'm quite fearful that the SD2 might snag onto something and twist and pivot on the USB-C port of the phone, which is a potential disaster!

SD 2 9.jpg

Thus, it behooves the user to perhaps be careful when bringing the SD2 out-on-the-go with a phone.


This dongle's DAC is an ESS sabre ES9270 chip, housed inside a 32-bit HyperStream®II QUAD DACTM frame. It plays PCM up to 384 kHz and DSD128.


I tested the SD2 with Android phones and on Windows laptops and PCs. TAKE NOTE: No Apple devices were tested as I am not an Apple user.

Tonally, the SD2 is on the warmer side with a slightly emphasized mid-bass. This tuning choice bestows a consumer-friendly tuning, bringing head-banging fun to the table. The bass is can be somewhat bloated though - this is apparent with complex bass tracks - and this region isn't too textured, but thankfully, it doesn't overly bleed into the other frequencies. The treble is decently extended, but is not super airy, with a roll-off in the upper treble.

In technicalities, when compared against other budget dongles, the SD2 has a wide soundstage with almost pin-point imaging, which is quite remarkable for the $30ish entrance fee. It is not the most micro-detailed in view of the tuning, with instrument separation sometimes smearing in complex musical movements.

This DAC/AMP is only single-ended, with no gain options. Power-wise, it outputs 70 mW, which is acceptable for a budget dongle, but is not the most powerful at this price-point.

My crucibles for source testing include 3 of my hardest to drive gear:
1) Final Audio E5000 (low sensitivity at 93dB/mW)
2) Sennheiser HD650 (high impedance at 300ohm)
3) Yinman 600 ohm (600 ohm impedance and 87db/mW sensitivity)

Driving to adequate volume is not the same as driving well, and though the SD2 could get the volume loud enough with these 3 behemoths, the transducers couldn't "sing". All 3 had bloated one-noted and untextured basslines. The E500 in particular sounding undynamic, though the HD650 had decent dynamics, but was compressed in soundstage. The Yinman 600 ohm sounded claustrophobic and lowFI, but this is probably an unfair transducer to test the SD2 with, as even pricier dongles and DAPs have trouble driving the Yinmans optimally.

The SD2 doesn't hiss even with fussy high sensitivity IEMs, which is much appreciated. Unfortunately, there is an irritating "Pop" sound heard when disconnecting transducers, even when the upstream source and dongle are muted - this could have been prevented with a "pop" suppression design I suppose. Thankfully, one can mitigate the "popping" via using an interim 3.5 mm to 3.5 mm adapter.

Hidizs has not included any output impedance (OI) specs on the product insert. To my ears, the OI is perhaps on the higher side as some low impedance gear plugged into the SD2 sounded a bit bass boosted. This may be a boon for some who want a warmer tonality, but purists who prefer a dead neutral dongle might need to look elsewhere, unless you are open to playing with EQ upstream.

The SD2 runs warm when powering hard-to-drive gear, but not overly hot, compared to rival dongles.


The SD2 will be compared against some other $40ish USD dongles that are single-ended.

Apple dongle (non EU version)

The Apple dongle is one of the cheapest dongles at sub-$10 USD, but it has a noodle-thin non-detachable cable, and feels quite filmsy compared to the sturdy SD2. The Apple dongle also does not have volume controls.

Tonally, the Apple dongle is dead neutral, with a comparatively thinner note weight than the bassier SD2. The Apple dongle has less power than the SD2, and is also inferior in soundstage and imaging. Micro-detailing is on par, but clarity is a shade better on the Apple dongle, as the bass is a bit less emphasized.

For diehard audiophiles, the Apple dongle is capped to a 48 kHz/24 bit maximum sample rate, whereas the SD2 can play up to 384 kHz/32 bit and DSD 128. The Apple dongle has no "pop" sound when disconnecting gear.

Tempotec Sonata HD Pro

The HD Pro is a neutral dongle. It has volume controllers and a detachable cable. The HD Pro is weaker in soundstage and imaging, but has a bit better micro-detailing.

The HD Pro is limited to 60 mW at 32 ohms, so it is marginally weaker than the 70 mW of the SD2. The HD Pro is also more bulky in size, though it is ice-cool during usage. The HD Pro has no "pop" sound when disconnecting transducers.

Fiio KA11

The KA11 is also tuned warmish, but it has 200 mW of power at 32 ohms, which is probably class-leading for a dongle of its size, easily dwarfing the SD2's 70 mW on tap. The KA11 gets hotter during usage, but understandably so due to the bigger power outlay.

The KA11 has no volume controls too, but it has no "pop" sound on removing IEMs due to the implementation of a "pop" suppression system. The KA11 is second class in technical chops, with a smaller soundstage and poorer imaging.


SD2 8.jpg

For a budget dongle, the SD2 is a decent offering, boasting of a fun, slightly bass-emphasized tone, with generous accessories - it even has a Lightning adapter for Apple users, which is frequently neglected with even more expensive dongles!

The SD2's calling card is its small pentagonal profile, which is pretty unconventional to say the least. This makes it an unobtrusive dongle for PCs or laptops - in functioning like a thumb drive - but conversely, it may awkwardly snag when placed in tight pockets or crowded bags.

Of note, the SD2 has a deceiving large soundstage and nearly pinpoint imaging, which is quite unexpected for the $30ish entrance fee - this is something found in pricier dongles usually. However, the emphasized bass goes for quantity over quality, and it may not be the tightest or fastest, especially when complex bass tracks come out to play.

For a budget single-ended only dongle, the SD2 pumps out 70 mW power, which should do an okay job for most IEMs (other than outliers like the notorious Final E5000). However, it admittedly loses to the Fiio KA11 in power, which as of the time of writing amongst the small and cheap dongles, has a class-leading 200 mW juice at 32 ohms; the SD2 beats the KA11 in technicalities though, so each has their strengths.

One bugbear during my testing was the "pop" sound when changing transducers - this can be mitigated with a 3.5 mm to 3.5 mm adapter - though it would have been great if there was a "pop" suppression added in the design.

In conclusion, the SD2 is not perfect, but it does more areas well than bad, and is a suitable everyday carry (EDC) dongle, especially for laptop or PC users who want something compact, with an expansive soundstage and solid imaging.
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Reviewer at hxosplus
The Tetris brick
Pros: + Crystal clear and transparent
+ Resolving and refined
+ Impactful and dynamic
+ Not much digital glare
+ Spacious soundstage
+ Good power for the size
+ Low power consumption
+ In-line control support and embedded microphone
+ Well made
+ Compact, lightweight and ergonomic
+ Good price to performance ratio
Cons: - Polarizing appearance
- Lighting OTG cable is not included in the universal retail package
- No independent volume control
- Slightly lean textures
The Hidizs SD2 is a portable USB DAC dongle without a cable that directly plugs in a host USB type-C port and delivers audio in a 3.5mm headphone output. The Hidizs SD2 not only supports in-line control but also features a high-definition microphone. Plugging it in enables SD2 to convert microphone audio streams to 24-bit, 48 kHz, ensuring clear voice transmission.

The Hidizs SD2 is equipped with the brand new ES9270 DAC chip by ESS that features a patented 32-bit HyperStreamII QUAD DACTM architecture. The chip supports PCM up to 384kHz/DSD128 decoding and has an integrated headphone amplifier that delivers up to 70mW+70mW@32Ω. The SD2 is compatible with Android, Windows, Mac OS, iPad OS and HarmonyOS with zero delay so it is suitable for movie watching and gaming. Furthermore the SD2 bypasses the integrated audio processing of mobile devices, such as smartphones and tablets.


Non Audio stuff

The SD2 has an aluminum alloy chassis crafted with a unique etching technique, creating a mecha style appearance with sharp lines and geometric shapes that reminds a lot of a Tetris brick piece. The two faceplates of the chassis are made from aluminum alloy while the outer perimeter is from resin material.

The SD2 features an angled 3.5mm audio jack that is inclined at 45 degrees for better ergonomy when you plug your earphones. Additionally the USB type-C plug is long enough to fit without the need to remove the protective case of the host device.

This is a compact sized (34.5×20×10mm) and lightweight (6g) USB DAC dongle that is easy to carry and use without adding much bulk to your phone. The SD2 is equipped with a tiny sample rate indicator LED that will turn red for PCM 44.1-48kHz and blue for PCM 88.2-384kHz & DSD128.


The package includes a USB type-C to USB-A adapter. Additionally the Hidizs official online store edition includes a complimentary iPhone Lightning to Type-C cable with OTG function to support iOS which is excluded from the universal dealer edition.

Audio stuff

The power output of the Hidizs SD2 is 70mW/32Ω, quite high and better than similar, compact sized USB DAC dongles that are equipped with one DAC chip. For the sake of comparison, the FiiO KA1 is rated at 45mW/32Ω and the ddHiFi TC35PRO at 65mW/32Ω. The SD2 is also quite efficient, I have measured power consumption at 0.02A/0.12W when idling and 0.07A/0.37W at full throttle. The SD2 runs cool during use and is dead silent without audible noise. The SD2 doesn't support hardware volume control and you get 15 steps of volume adjustment through your phone.

For this review I have used the Penon Vortex, the Hidizs MP145 and the Hidizs MS1. The Hidizs SD2 provided good loudness and dynamic range with all three of them.


Audio quality is exceptionally good given the humble size of the Hidizs SD2. The sound is crystal clear and transparent with great fidelity. Frequency response is flat without any audible deviations from linearity.

The bass is fast, tight and controlled with good definition and layering. The SD2 is dynamic and impactful as long as you use efficient and not difficult to drive earphones. The texture is not that visceral and weighty but you wouldn't call it lean or dry either. Mid-range clarity and presence are very good, the sound is open and spacious with excellent articulation. The timbre is quite natural and realistic with plenty of harmonic variety and without sharp edges or any kind of shoutines. This ES9270 DAC chip by ESS seems to be well designed and produces sound without any severe artificiality and digital glare. The SD2 is not as warm or organic, like the iFi Go link but it is certainly not sterile or lifeless. The SD2 is fast, energetic, luminous and just a bit treble forward but thankfully not aggressive, bright or harsh.

Detail retrieval is excellent for the category and the overall resolution is very competitive even when compared with more expensive USB DAC dongles. The soundstage of SD2 is open, spacious and surprisingly well extended with excellent stereo imaging and sharp positioning. It pairs well with all kinds of earphones and makes them sound grand and immersive.


I am not going into detailed comparisons, it gets pretty vague after a while, the market is flooded with USB DAC dongles that sound more or less the same with minor tuning variations. Some of them are warmer and more organic sounding, others are sharper and brighter while the rest are flat and balanced. The Hidizs SD2 mostly falls into the last category despite its mildly energetic nature. There are also differences to power output, size, weight and extra functionality like app support. The Hidizs SD2 is more powerful than other competitive DACs, it is also lightweight and compact but it doesn't support hardware volume control and app connectivity.


For $39.99, the Hidizs SD2 is a very competitive USB DAC dongle worth checking because it is compact, lightweight, well made and has excellent sound performance with plenty of musicality and great technicalities for the category.

The Hidizs SD2 was kindly provided free of charge.
The price is $39.99 and there is a Special Price promotion of $31.99 (Limited to 200 units) if you buy from the official Hidizs online shop.

Special 5% discount available with the code ICHOS5

Amazon link

All links are not affiliated
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New Head-Fier
(Possibly) Entry Level Dongle DAC Killer - Especially for Bass Lovers.
Pros: • ONLY $39.99
• Unique design, compact, and highly suitable for mobile use
• Support Microphone input
• Good quality control resulting in excellent finishing
• Sufficient power for the majority of entry-level IEMs
• Supports multiple OS devices
• Ideal for bass and soundstage enthusiasts
• Within its price range, provides technical quality and sound above its level
Cons: • Unique design may not appeal to everyone
• Requires caution as the dongle attaches directly to the device (without a cable), making it prone to knocks and damage
• Lack of a USB C female to USB C male cable to address the above weakness
• Separation tends to overlap slightly when there are many instruments
• Nothing in this price range
I would like to extend my gratitude to Hidizs for sponsoring this review by sending me the SD2 unit to evaluate. All opinions expressed here are honest and uninfluenced by any party. I review simply out of interest, not out of necessity, haha.
It all began when I won the Hidizs DAC Dongle S9 Pro Plus with Martha giveaway, which led to some "friendly" chats with Hidizs (I guess it was only me claiming it was friendly, haha JK), and they offered to send me their latest product, the SD2 Dongle DAC, which was soon to be released. So let's dive into it.
Hidizs Official Website:


Amazon Link:




All impressions and reviews are subjective and are based on my belief that "I review when I feel like it, not for the money because I can afford it lol". Agree? Okay. Different opinion? Okay.
• But you might think I'm saying this because Hidizs sponsored me, right? Well, read until the end; I'll tell you everything, even the negatives, upfront. Haha.
Important!! I recommend auditioning it yourself, in case my ears need a visit to the ENT doctor or you do (haha).


• What unique-shaped Dongle DAC is out there?
• What affordable yet good Dongle DAC that compatible with Microphone input is available?
• What entry-level Dongle DAC is perfect for bass enthusiasts?
• Tired of reading, just want to read reviews.


• For Treble lovers, shining, shimmering, splendid!
• Clear Clarity, good Imaging, outstanding Soundstage.
• Sweet and fluid Vocals.
• High-quality Bass presence but not for bass heads.


• IE600
• Symphonium Meteor
• Kontinum Soara
• Youtube Music
• Tidal
• Hiby M300
• Hidzs SD2
• Fiio Q15
• Hidizs S9 Pro Plus with Martha
• Lenovo Office Laptop (What series is this?)


For the entry-level price $39.99, this is the standard box you'd expect at this price point. Nothing flashy, straight to the point. But in terms of completeness, it's more than enough:
• SD2 Dongle DAC
• USB C Female to Lightning (for iPhone 14 pro and below) cable
• USB C female to USB A converter.
• Manuals and warranty card
  • According to Hidizs website, the cable for lightning to 14 pro and below is only for direct purchases from Hidizs. If purchased from a distributor/partner, it's still undecided.
  • I've discussed with the Hidizs team and suggested changing the USB A converter to a Female USB C to Male USB C cable because the usage of USB C is more common now and it would be more convenient for those who struggle to plug into mobile devices due to casing.

• Physical:​

Imagine grabbing a 300ml mineral water bottle cap. Got it? Now, the SD2 is just about that size with an added Male USB-C protrusion. REALLY SMALL! Besides its small size, it's also extremely lightweight, making it prone to getting lost if you're carrying it around. But the upside is it's easy to store anywhere. The downside is the material feels cheap, like it's made of 3D-printed plastic. But for this price, it's okay, no defects or anything; the quality control is good.
For some people, I'd suggest being more careful with this because I'm a bit worried that if it gets knocked, it might break, and the USB C pin might get stuck. Not that the pin and jack are bad, but there's a possibility they might break if knocked.

• Sound Impression:​

• Bass:
One word, GREAT!. This DAC has a warm signature. For bass heads, if you already have bass-heavy IEMs, using this will make it even deeper. With proper deep bass intensity and good quality. The rumble, when paired with IEMs that use DD, feels even better. But in my opinion, the sub-bass has a slight deficiency as it feels less open and unnatural, albeit slightly.
• Mid:
The midrange presentation feels slightly recessed in the middle with a smooth yet slightly dry character. If you're a fan of female vocals, it might feel a bit dry and less optimal. For male vocals, it feels like being in the Sahara desert, hahaha.
• Treble:
For this price range, the treble might not be the main star of this DAC. Although the sound produced doesn't fall into the category of shining-shimmering-splendid, the treble presentation, which is not piercing and has sufficient extension, might suit some people who are sensitive to treble. For the price? I couldn’t ask for more, this is beyond it price range.
• Clarity, Imaging and Soundstage:
Clarity: Clear, distinct, clean. All instruments sound clear and good, vocal articulation is also presented well. However, when there are many instrument sounds in some songs, the upper mid and treble parts of the SD2 can get overshadowed by the bass.
Imaging: One of the aspects that surprised me about Hidizs' tuning, aside from the bass, is Imaging. All instruments are depicted with good positioning. Micro details, even in this price range, are quite detailed.
Soundstage: While the Bass and Imaging are good, I feel the Soundstage is even better! Hidizs' tuning for the Entry-Level Dongle is really impressive. The spacious sound presentation makes listening to micro details more enjoyable.

• Specifications:​

• ONLY $39.99!!!
• Dimensions: 34.5×20×10mm
• DAC Chip: ES9270
• DSD: Native DSD64/128 • PCM: Support up to 384kHz/32Bit
• Output option: Single-ended 3.5mm
• Sampling rate indicator: Support
• Red Color: PCM 44.1-48kHz • Blue Color: PCM 88.2-384kHz & DSD
• Shell material: Aluminum alloy + Resin
• Transmission interface: Type-C interface
• Supported System: Android, Windows, Mac OS, iPad OS
• Net weight: 6g
• Audio Parameters: Test Conditions @32Ω Load
• Frequency Response: 20Hz-40kHz
• Distortion: PO (3.5): 0.0015%
• Signal-to-noise ratio: PO (3.5): 118dB
• Separation: PO (3.5): 64dB
• Output power: Up to 70mW+70mW SE 3.5mm
• Packing list: SD2×1, Type-C to USB-A adapter×1, Lightning to Type-C cable, User manual×1, Warranty card×1
Based on these specs, I also tried driving the Symphonium Meteor, which is quite heavy to drive and even feels heavier than typical Planar IEMs. And the Symphonium Meteor was driven well and "sings". For those wondering, "Can it drive Planar IEMs?" the answer is Yes. As long as it's entry-level (or low-budget). I haven't tried it with the Symphonium Crimson or other Flagship IEMs that tend to be heavy. If it's for headphones, it's best not to try it. It won't be optimal, and you might be disappointed, huhu.


I tried comparing it with the DACs I own. Well, it's not exactly comparing apples to apples, but it's what I have, haha (vs S9 Pro Plus with Martha). I'm also comparing it in terms of price to performance (which one is more worth it).
• Bass: Both are equally good. The SD2's bass feels slightly more overpowering compared to the S9 Martha. But Martha feel more natural and better quality. I was genuinely surprised by the SD2's bass.
• Mid: The SD2's vocals are more recessed but still in the middle, smoother but unfortunately drier than the S9 Martha, which is much more advanced and has a more open vocal. If you're listening to male vocals on the SD2, it feels as dry as in Sahara dessert.
• Treble: The S9 Martha's treble is more natural and sparkling compared to the SD2. It's quite apparent.
• Clarity: The S9 Martha is clear, and its separation is superior to the SD2. Although the SD2 has good clarity, when there's a crowded arrangement, the upper mid and treble of the SD2 can get drowned out by the bass.
• Imaging: This is almost on par with the S9. Both have excellent imaging.
• Soundstage: I tip my hat to Hidizs, both have really great soundstages for an entry-level dongle. But the S9 Martha is still better in terms of an open sound that makes the soundstage slightly wider than the SD2's.



Overall, the SD2 is highly recommended for an entry-level DAC.
• The SD2 is a serious contender for other entry-level DACs trying to enter this price range.
• If you like bass, a spacious soundstage, need it for mobile use, don't want the hassle, looking for affordability, compatible with microphone input and unique design? The SD2 is an option you won't regret.
• You get what you pay for. Although the sound quality is outstanding for its price, there are some trade-offs, especially in terms of vocal and clarity. In addition, the material and design, while very versatile, may not be to everyone's taste.
• The SD2 is definitely worth using or even just collecting, especially for bass enthusiasts and mobile users because it supports many devices.
• Suitable music genres: Electronic, Rock, Metal, EDM, Pop
That's all. Trust your ears. Goodbye.