HIDIZS SD2

General/Packaging/Build
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.

Specifications

• 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

Foreword
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

Features

• 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

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.

Hidizs​

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

Unboxing / Build / Design / Internals ​

Unboxing ​

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.

Design​

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.

Internals ​

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​

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Features​

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​

Click to expand...

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Drivability ​

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.

Midrange​

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.

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Technicalities ​

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.

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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.

Conclusion​

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.

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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!

★ Introduction :-


Hidizs 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.



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 :-

Dimensions : 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.







★ 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.






★ 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.






★ 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.






I've provided the purchase link below for your convenience


Hidizs website (link is not affiliated)

Or

Amazon store (link is not affiliated)