• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Hidizs S9 Review (Headphone Adapter)


Staff Member
CFO (Chief Fun Officer)
Feb 13, 2016
Seattle Area
This is a review and detailed measurements of the Hidizs S9 USB-C DAC and headphone amplifier. It was kindly purchased new by a member and drop shipped to me. The S9 costs US $112 on Amazon including Prime shipping. There is a 5% discount there as of this writing.

The S9 comes a in stout thumbnail sizes package:

Hidizs S9 Review headphone amplifier DAC balanced.jpg

There are no controls on it unlike S8. A multicolor LED indicates the sample rate of the music being played. It is quite bright.

The predecessor to S9, the S8 had up down volume control which I miss here.

You now have a choice of balanced and unbalanced outputs:
Hidizs S9 Review headphone amplifier DAC phone tablet balanced.jpg

No USB-C cable came with it which was surprising as they almost always include such.

In use, the S9 got a bit warm indicating it is rather power hungry.

Hidizs S9 Measurements
Let's start with our usual dashboard of 1 kHz tone, testing both outputs (2.5mm balanced and 3.5mm unbalanced):
Hidizs S9 Measurements Unbalanced.png

Hidizs S9 Measurements balanced.png

Hidizs delivers once again with desktop class performance. Distortion is well below threshold of audibility and we have 4 volts output which should produce lots of power for high impedance headphones.

Best Phone Table Headphone Adapter.png

Signal to noise ratio is excellent for a dongle and even desktop class:

Hidizs S9 Measurements SNR balanced.png

Not so much at 50 millivolt though so you may get some hiss with very sensitive IEMs.

Jitter shows the typical interference we see in these types of devices but levels are quite low:
Hidizs S9 Measurements Jitter Unbalanced.png

Multitone performance is desktop class:
Hidizs S9 Measurements Multitone balanced.png

Due to the way these DACs announce themselves to Windows, I can't use my analyzer to run sweeps properly. So no IMD vs level test. I will show power sweeps but note that the noise floor shown (sloping down part of the curve) is wrong and artificially elevated. Just look at the graphs for maximum power and distortion:
Hidizs S9 Measurements Power into 300 balanced.png

Hidizs S9 Measurements Power into 33 balanced.png

This is a powerful dongle:
best tablet phone dongle review 300 ohm.png

best tablet phone dongle review 33 ohm.png

Power is everything in this class product and the S9 delivers so strongly.

Hidizs S9 Listening Tests
I started testing with my Sennheiser HD-650 high impedance headphone using unbalanced output. There was enough power to generate good volume. Everything was right with the sound with great fidelity, detail, and overall performance.

I then switched to my tough to drive, Ether CX 25 ohm using balanced connection and the S9 drove it as it it was a desktop class amplifier! I had to actually turned down the volume for comfortable listening. The sound was a delight with excellent bass, detail, etc. It was so good I did not want to stop and take pictures of S9 to publish this review!

The Hidizs S8 was a ground breaking adapter delivering stunning good performance. The S9 takes that performance and adds balanced output to deliver even more power at the same cost as the S8. The result is a tiny device that delivers desktop class performance. You pay more than $9 that throw-away dongles cost but in exchange you get a serious player which delivers great fidelity in wide range of headphones.

It is my pleasure to highly recommend the Hidizs S9.

Edit: video review available now:

As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Last edited:
Wow. I just might have to order this one for the Dan Clarke Aeon RT when I use them with the iPad Pro.
Looks like an overall great dongle, better than I expected. Only one thing I find weird, it uses an AK4493 chip yet the dashboard especially the balanced output has a lot of higher order harmonics. Pretty much every recent AKM device measured so far with this chip has very few upper harmonics which seemed to be its strength, as it is on the hidizs I assumed they used an ESS Sabre chip. No idea how they implemented the AKM to make it behave so. Probably not an audible complaint, though.
@amirm seconding output impedance :) probably comfortably low?

PS this is probably one of the first dongles to surpass the E1DA 9038s in both SINAD and output power? :D
Interesting. For once, the balanced is really better than unbalanced, unlike ibasso DC03 vs 04 or the first 9038D vs S. This is what it should be like, i.e. with a diff out DAC it should be easier to get a clean diff signal than an unbal signal.

It also holds its own against Sanskrit 10th MKII and Topping E30, both of which have the same AK4493 but use unbal out.

Interestingly, all three of them have some left / right differences in the 4th / 5th harmonics. Hidisz and E30 do without a 4th harmonic which the Sanskrit cannot.

Will we be seeing many of these after the AKM fire?
Interesting, so am I right in thinking this is probably ok power wise for a Hifiman Sundara? But may not be great for IEM (moondrop starfield) based on the 50mW test?
Hidizs S9/ Tempotec HD Pro didn't work right despite good measurements. I wouldn't rush to purchase this thing.
You ment S8, this is S9. Obviously this is totally different device than Sonata BHD but it would be interesting to see how they compare and did Hidizs switched the OEM this time around. For some folks those worked so good that they switched their desktop DAC's for them for others they didn't.
You ment S8, this is S9. Obviously this is totally different device than Sonata BHD but it would be interesting to see how they compare and did Hidizs switched the OEM this time around. For some folks those worked so good that they switched their desktop DAC's for them for others they didn't.
No way. It delivers only 1,9V into 32R, this is by far not enough for planars.

They forgot to give you the cable lol, it came with the device for free.

EDIT: (Two actually, a long one and a short one, also a Type-C to Type-A adapter, all free.)
Top Bottom