Best Portable Headphone Adapter? Hidizs S9 Review 

Hi Amir. Will you also be reviewing the Hidizs S9 Pro that will be launching soon?

You are the best, Amir.

Another great, unbiased review … thanks Amir! Purchased this from Amazon after watching your review. I usually take reviews with a “grain-of-salt” as the reviews are subjective based on the reviewers likes/dislikes … that’s why I love your objective reviews. Really gives us a good baseline for comparison, before subjectivity plays its part. Very much enjoy your reviews, keep up the great work. You’re doing all of us a great service.

i bought the dragonfly black like 5 years ago, making only dust these days. Now I use the well reviewed (well... subjectively well reviewed....not at Amir level of course) FiiO BTR5 in DAC form with my macbook pro, specs says produce 242 mw at 32 omhs in the balance output, the little device has volume, battery as is also a Bluetooth5.0 Receiver with LDAC, aptX HD, codecs. to be fair it is not as small as a dongle but still is a quite tinny device at 1.55 ounces. Roughly same price as the Hidizs. So in paper could be a better deal, but only Amir can tell us if it is truly better, I love your channel!!!!

Also placed an order for one based on your thorough review! I woudn't have known about this device if it weren't for your Audio Science website. Subscribed!!

Love your approach to fine audio. It brings us down to earth and practical information.

Great review. Subscribed. I'm still holding on to my LG V30. The dac is amazing.

What an impressive little gizmo! I liked the flow of your presentation and especially all the graphs and infographics. Really thankful to see that 32 tone spread, it really puts me at ease, 1khz data always leaves me wondering ha ha. I know allot of color-theory is based around having simultaneously balanced colors across the visual spectrum, for example blue and yellow go well together as yellow is a crossover of Red and Green, so together with Blue it stimulates all 3 cones in our eyes of RedGreenBlue. I think music theory may be the same, where there's some psychoacoustic joy in perceiving just a few small portions of the auditory spectrum simultaneously, I find it kind of interesting to think of an amplifiers performance in that simultaneous broad-spectrum context. A smooth linear noise floor is kind of like having all he colors present which would just wash out as white, I guess that's why they call it white noise. Whereas when you get non linear jaggies like this Dongle has, they're more like distinct colors, which may present to us some theoretical patterns and pairings of jaggies that stand out like colors complementing each other if they strike the rite interval. To stretch the metaphor, these jaggies at inaudible levels is like color theory in the dark ha ha ha. So like a linear noise floor of higher volume would be like a white background with the paint of music on it, like painting on a white piece of paper. While the lower the noisefloor gets us more into grey and black approaching HDR like black levels allowing the musical colors to really glow and shine on that dark background, but in a scenario like we see with this dongle as it gets "darker" and quieter, it also moves out of color neutrality and has a slight tone to it, so now it's like were painting on black construction paper that was left in the sun and washed out a little bit green. I tend to feel it's better to have the lower noise floor, than to pursue linearity, because it's getting it even further outside of perception to avoid interactions that would possibly bring it into perception. But perhaps in some real world scenarios, there's knock-on effects that in certain contexts make linear better. At -120db it's inaudible, and arguably of no significance, what I wonder is if the noise is still cumulative with the signal content? like if we added 50db of white noise, would the jaggies add cumulatively and move that inaudible texture up into the audible range? or if we had tube distortion would the noise balloon the harmonics into crushing the high end resolution. It would be cool to see how a signal chain of equalizers and DSP toys transmutes a DAC's jaggies through those layers of cumulative distortions. My desktop setup is like a trainwreck, with boxcar after boxcar of signal chain modulating gizmos that I just like playing around with ha ha ha. Anyway thanks for the video! keep up the good work!

Love your reviews man gotta say. Also bought the s9 pro based on your review of the 8 and 9. I was very impressed and even bought one for a friend. It drives my hd650s with east also drives even my hifiman sundaras in Single ended mode no problem. Great and thank you sir.

Just placed an order for one. I get the feeling that watching this channel and reading your reviews are going to get a bit expensive for me lol

I picked one up based on this video. Look forward to trying it, but hard to go wrong at the price. Thanks for the interesting report.

Greetings from Mumbai, India . Excellent, thanks for the technical, objective analysis. Thanks Samir

Purchased it based on your recommendation! The THX was my first choice but too expensive for my budget, still I think I made the right choice, sound is clean and very powerful. I'm using it at the gym or while bicycling and couldn't be much happier! This dongle gives me tremendous pleasure. 🇨🇦

I bought one and using with Sennheiser HD650. Great combo. Thanks Amir and greatings from Poland.

Love your insights man. Thanks.

big fan of your website. great to see you have a youtube channel too now! subscribed instantly!

WOW! Just purchased from Amazon within 60 seconds of watching Amir's review. If this sounds half as good as the numbers indicate, it's an incredible value. The idea of pairing this to my phone to power Sundara w/balanced cables on-the-go is beyond exciting! Thanks Amir!

Looks like 6 of the same 25 people that usually downvote his videos, are missing here. Good video man. Glad someone’s out here providing objective measurements.

Thank you for a fantastic review 🙏

the definition of no-nonsense review........real smart........a review on hidizs s9 pro is a must Sir.........if possible..........thanku & cheers!!!!!

Tried a few including dragon fly cobalt ,earman sparrow and this s9 . Ithini the sparrow just edges it on balanced and at low volume.(unimpressed with the cobalt) ,however this has more drive and is better at higher volumes all at half the price so I kept the S9. Great review thank you. I use Shure 846 for reference.

Fantastic review!

Such a pro-review, GR8 ! I ordered the new Hidizs S9 PRO, wondering in what way it beats its predecessor the Hidizs S9. ✌ Subbed.

Very useful recommendation. I will try this with my Aeon 2 Noire, but have to make a balanced cable first.

Hi Amir, thank you very much for all the effort you put into your measurements/reviews. Always a joy to watch. Any chance you are going to measure the FiiO Q3? All the best from Germany.

I just ordered the Pro version and it's rated at 200mw @ 32Ohm. Thanks for all the data.

Bought one now after seeing your video

REALLY enjoying this Channel. Sadly..... I've had to order this little device. Couldn't resist!

I just bought the S9 Pro. It sounds amazing~!!

The facts nothing but the facts ...... Delightful!

i bought it yesterday i wanna say this is the best tiny dac i have ever owned thank you so much for your recommendation

Yes. I get the S9 (AK-chip) this week :) I allready have S8 and S9 Pro.

Had mine for a few weeks driving my hifiman Anandas it sounds just as good as my E30 + smsl sp200 desktop setup.

That was a great review 🤩 . Now there is the s9 pro if you can get it and test it cz the s9 is no longer available (thnx to akm Factory fire) . Plz we need u to get it and test it 🥺❤️

@Audio Science Review Thanks for this review, Amir! 👍 With so many of these portable dongle type USB DAC/Headphone Amplifiers available now, it's really hard to know which one to go with BEFORE buying it and actually testing it with your own high-impedance headphones. It would be great if they added a small USB Type-C or mini-USB jack/port to function as a dedicated power input so we could use a small, slim, pocketable smartphone-sized rechargeable 10,000mAh USB Power Bank as a "clean" PSU. Yes, that would somewhat defeat the minimalist/portable aspect, but if your portable source unit's battery dies quickly while using this, well, you're "dead in the water" so to speak without gaining very much listening enjoyment. Do any of these small, portable and good-performing DAC/Headphone Amplifier units offer a separate power input jack? ...like the Apple Camera Connection Kit dongle or most USB to HDMI output dongles? I'm looking for a new, small USB DAC/Headphone Amp to combine with my *Samsung Galaxy Tab S2 8.0* GSM/LTE cellular 8" Phablet (# SM-T715Y). This combination would function as my Car Audio Source or "Head Unit". Preferably, the DAC/H-P Amp would have a ~4v Balanced Output to feed into the multi-channel *miniDSP C-DSP 8x12 DL* processor that I use in one of my "high-end" car audio systems (I'm a long time follower/internet buddy of Erin Hardison). I use the Android *USB Audio Player Pro* app on the Samsung Phablet. These types of USB DAC/Headphone Amps really kill the battery quickly in your portable Smartphone or Tablet if you don't have a way to simultaneously charge them!

I would go with the Quadelix 5k that you reviewed since it has 10 PEQ filters built-in via its application. Sure, Distortion didn't measure great but S/N is really good and it provides a lot of power.

Have you reviewed the Shanling UA 2? It's also very good. Your reviews are real science. Very nice.

It would be very interesting to see how it compares to measurements of TempoTec Sonata BHD. This is because iBHD is balanced as well, but (in contrast to Hidizs) has volume control buttons.

Fingers crossed, hoping TempoTec comes out with a lower priced version.

So, for balanced use with my iPhone, the ddHiFi TC44B (also highly reviewed by Amir) beats the Hidizs S9 Pro, hands down. Both have excellent sound quality, but the S9 Pro draws so much power that the volume starts clipping in the 60-65% range. The TC44B, while not being as powerful on paper, cleanly powers headphones to 85-90% full volume on my iPhone. In addition, I think the Cirrus Logic DAC chips sound a little more musical to my ears.

Have to reviewed the upgraded one with the ES9038Q2M DAC chip from ESS Sabre Technologies?

thanks for the quality content Amir. it would have been great if you tested for the steepness of the volume control which was the main complain people had with the S8, from both the in built volume buttons (which might be the reason why the removed them altogether this time around) and the system volume in a phone. I am sure we will be discussing this in the forum in no time but it might also be of concern for the folks at youtube

Hey Amir! Are you going to review the new Hidizs S9 Pro?

Hi. Your review vlog is next level, very comprehensive and i really appreciate it. I finally received the S9 about a week ago. was very happy with it up until a few minutes ago. It won't come on whereas all the times I used it up until now it came on just fine by itself. Is there anything I can do to get it to work again? Any reason it would just up and stop functioning?

Great review. Is the S9 compatible with the upcoming Apple Lossless format?

Is there a chance you'll be reviewing Shanling UA2 usb dongle? nice video btw keep the work up

I have purchased the Tempotec sonata HD pro after reading the review of Hidizs S8.Really happy with its performance.Unfortunately when using with Android phones,I simply cannot bypass the Android audio control/driver- whatever that thing is called.With laptop it sounds great when combined with Fiio K5.I tried Hiby music app,but was disappointed with audio quality. Thanks for all the hard work you put in.

Would love to see a review of earmen eagle and ikko zerda compared to this for balanced output performance. Thanks for this great review.

Mine's arriving tomorrow

I'm not sure if you done this but could you test if balanced iem cables and dac makes a audible difference. I'm curious because I recently purchased a sensitive iem ( Fearless S8P) and I'm currently using it with my phone's 3.5mm jack (Lg V20 quad dac). is the upgrade to balanced really that audible that everybody recommend it? PS. I recently found your channel and immediately subscribed!

Can you review Shanling UA2 and UA1 and compare it with Hidizs z9 pro and 8... It would be lovely to see the comparison and also the amount of power they suck when used with mobile device

Great video! i wonder if adapter like these affects microphone quality?

Nice testing-methods I have to say, thx for that; I whould love to see audio-tests for my Denon AH-D 5200 Headphones and IPOD SHuffle 1First Generation. As I remember right, they say, the IPOD Shuffle 1G was the best of the best at the time in terms of audio-quality..., but was it? I use it until today, and I still like it very much! But is that objektive or subjective?

Good video... hope you make other USB dac's review..

These dongles are very underrated. 3 years ago you had to spend 100-200$ to get decent sound quality on PC. Apparently we only needed to get rid of 3.5mm in smartphones so that manufacturers would start making cheap decent dacs. Now it only takes 10$ to get transparent dac+amp+mic input with -85 thd+n. Some still pretending that they are only for mobile use or they are just an "adapters". But i think even 0.5V would be enough for many headphones on the market to get 100-110dB and some dongles have nearly 2V undistorted output. Not to mention state of the art projects like E1DA

Thanks for this Amir. I actually bought one of these last night just before this review was posted. Seems like it was a good decision based on the measurements. Was it not possible to do a linearity test?

Now Im going to need to buy one.... have you reviewed the BRT5 ? that my fav at the moment

AKM makes good sounding dac's. Have it in my ONKYO too. (AK4490)

I've got 2 concerns about this DAC: 1 - it's not shielded so it easily picks up interference from phone's GSM/WIFI 2 - if you have IEMs like Shure SE846 then at v.low volumes you might hear a lot of noise when watching videos on e.g. youtube or listening to music on default music player or spotify, yt music etc. The only solution for issue no. 2 (that works for me) is to use upsampling to 24bit in USB Audio Player Pro or Poweramp.

Hi Amir! Just purchased this little DAC to compare with my Audioquest dragonfly red on hd650. I came across a review you wrote on a graph that compares SINAD and found the red in tier 3 or 4 :(. I also read something from the net that there's a difference between balanced and true balanced in how it works (especially on ps audio where paul explains how balanced works). I am a bit confused. Can you enlighten me a bit? and also how does the balanced work on this particular DAC. I heard hd650 has a wider soundstage using balanced. (according to z review I think. ) Very much appreciated.

Will you be reviewing the S9 Pro?

Thanks for the video. I am very new to this category and still trying to learn. I have an iPhone and as you know Apple Music now supports lossless and hi-res lossless. I recently purchased the $9 Apple lighting 3.5 mm headphone jack adapter. It includes a built in DAC. Have you done a review of this adapter? If yes, do you feel it is a great value for $9 and a good choice for an iPhone-Apple Music user?

Welp, already returning mine. It cracks and pops, as well as has some sort of buffering issue where it occasionally drops samples and causes a hitch in the audio. Other than that it's a noticeable upgrade over my current piece-of-crap DAC/amp, but the quality issues naturally overshadow the sonic performance. I noticed quite a few Amazon reviews complaining about QC issues like this.

I would love a test of "burn-in" amplifier and dac. Some brands state hours or weeks of burn in before they sound good as they can. I really suspect that at first they sound not so good but after a while you get used to that sound so you like it more. Is there any burn in in cap,transistor,etc..? From what I leaned at school they dont change value over hours of use. yes over time caps, resistor value will change.

Better performance from the Hidizs S9/S9 Pro, or from the Topping NX4 DSD?

does the volume you listen at impact what level of performance you should pay for in a source when you do not want to spend anymore than you need? I'm rural ontop of a mountain in the woods with a passive pc etc etc so my listening room has a background noise level of 13db which makes like 75db sound loud as hell and even before I lived here I never really listen loud. Does this mean the thresholds for what is considered strictly transparent change? if so which ones

Would this be sufficient to drive a pair of Audeze LCD-2 classics?

The S9 or Tempotec Sonata HD Pro if I only use Moondrop Blessing 2 IEM's and Yamaha HS8 active monitors with it?

Could You do a review and analysis of the reftone Ld-3b. Single 5 inch speaker.

Can you measure the effect of placing a doorstop on top of a DAC? For the memes, please please please ... or ok, vibrations in general, shake it, hit it with a [rubber] hammer during measurement ...

For the price and convenience I would like to have MQA support as well, you know, for Tidal Master listening.

Will this drive a Fostex T50rp? Fulla 2 isn't quite cutting it.

The analyzes are surprising, but what about the noise of the PSU of a PC? Being a dongle, where are the filter/reserve capacitors, are they really needed?

I would like to see review of the most populat one, the Dragonfly Cobalt

Amir, pls test E1DA 9038D - unbalanced version of 9038S you’ve tested some time ago

Please compare dongles u reviewed with Shanling UA2 Dac/Amp

Hey! I have been experiencing popping and sometimes crackling noise when I pause or play music. I am afraid of damaging the headphones (Audeze LCD-2C). Any help is much appreciated.

Hidizs s9pro vs audirect beam 2 which one is more better ?

I got one that faulty, with the audio clipping, stuttering. Hidizs sent me a new one, hope it works well.

Amir I hope you will forgive me posting a bit off topic but I wanted to say something about the measurement/ golden ears argument and this is your most recent video. You often use an analogy with medicine when arguing for a purely evidence based approach, one with which I mainly agree. However.. I have been a physician for 35 years. When I started in medicine beta blockers were contraindicated in heart failure. The evidence we had at the time suggested they killed people by reducing the hearts capacity to pump forcefully and efficiently. Now one of the first drugs we reach for when we diagnose someone with heart failure is a beta blocker. They are invaluable and save lives. Turns out we had an incomplete understanding of the mechanism of the ailment and the way the drugs worked. There are many other areas where medicine has evolved as the science and our understanding evolves. Areas where we were completely wrong but for the very best reasons. It is likely that the physical science of signal production, transfer, conversion and music reproduction will evolve too and that there is stuff going on which we don't understand and can't measure. Yet. All that before you bring psychoacoustics into the equation. I am all for relying on the best evidence available and debunking marketing nonsense but perhaps we need to be more willing to admit we may only be seeing part of the picture. Of course the companies building stuff are working with the same level of scientific understanding you are so challenging unsupported claims is entirely legitimate.

If I get a Hidizs S9, I would be plugging into a desktop PC. Is there a benefit to using a USB 3.2 port instead of the USB 2 or original USB ports ?

I have a question for you: does using European equipment (designed for 220V) in the US (using a step up-down converter to 220V) make sense or does the converter degrade performance?

I suspect it might have the same problem as the Apple USB-C adapter has for me which is it gets too loud too quickly for low impedance phones like IEMs, when used on Windows 10. Key phrase here is "when used on Windows 10." I know it's meant for phones.

When fiio btr5?

:( still sad the meizu hifi pro disappeared so quickly, one of the best for the price PS: this is great too but almost three times the price

Is this review the S9 with the AK4493EQ or the S9 PRO one with the ESS9038Q2M DAC chip? I see both for sale.

Please do a review on the E1DA 9038D!

please help me with an answer and tell me why hidizs s9 pro does not connect to my phone, did I miss something?

How does it compare with E1DA 9038S?

will you ever get around to reviewing network streamers?

is it an upgrade to the hidizs s8?

I have a dumb question - most of your tests were in "balanced" mode. Would the performance be the same in unbalanced mode?

Sir s9 pro or btr 5 for best audio quality?

They changed the DAC chip to ES9038Q2M instead of the AKM (fires suck).

Thanks Amir. I bought this based on your review. However, I cant figure out how to connect this to iphone 12... i bought a small cable with lightening one end and usb c other end didnt work (the part that goes into the DAC needs to be longer than normal)... I tried my charging cable with usb c and lightening also didnt work. I bought a small attachment with female usb c to lighterning in order to use their usb c cable... also didnt work. Can anyone recommend me a cable or attachment to use this to listen on iphone 12? Thanks

Could I share l share this over a USB-C hub between phone and PC?

3:00 Balanced

I am confused on the use of this device. I have an ipad Air4 with usb C socket. I use a usb to 3.5mm adapter for headphones. If I use this device instead of my adapter what exactly does it do? Surely to use the DAC in this device the output from the ipad needs to be a digital stream not just audio that normally powers headphones?

I will stay with my Benchmark DAC2. Sounds good with my AKG K701 and also via XLR on my Yamaha A-S2100 connected to DXT-MON. 😁

This is a definitely impressive piece of gear and If I would be traveling more than I do now it would be a great buy. However I still use and keep an Apple Dongle. If we ever do a SINAD to $ Ratio, this would easily be number 1. Lets see 99.001/$9.99 = 9.91 S$ . Now lets do it for the HIDIZS S9 112.63/$119.99= .9386 S$. What about Topping DX3 Pro 106/$224.99= .4711 S$. Impressive for the HIDIZS even blows away the Topping desktop almost double the ratio. However Apple is also a great deal.