Hidizs S9 PRO Measurements (DAC Dongle)

[VintageFlanker]

Hidizs S9 PRO (short) Measurements
​

Hi folks,

Here is a quick review, measurements-based, of the Hidizs S9 PRO portable USB DAC/Dongle. It has been kindly sent to me by a French fellow. The S9 PRO has been introduced only few months after the S9 (1st gen), that Amir reviewed a year ago. As opposite to the previous model, which used AKM AK4493, the "PRO" now comes with ES9038Q2M from ESS. No doubt, the change has been closely related to the AKM shortage that started late 2020. It costs 109€, tax incl as of this writing.​

The Hidizs S9 Pro is a very light (11g) and tiny unit (18 x 59 x 8mm) made out of aluminum and glass. It has no physical volume control, the latter being done in software domain. The logo is backlighted and indicates sampling rates using different colors. You see two outputs: one 3.5mm TRS (SE) and one 2.5mm TRRS (BAL). Due to lacking of both correct cables and personal time, I only tested the balanced output for today's review.​

Only input you will find is (OTG) USB-C. Note that, being a dongle, the S9 Pro is not self-powered but feed by USB. Besides, be aware that it can run quite hot and may drain your phone battery fairly fast when used on the go...​

Measurements​

Disclaimer: Measurements you are about to see are not intended to be as precise or extensive than what you get from a 30k€ AP. There is obviously both hardware and software limitations here, so not quite apples to apples comparison with Amir's testing. Still, this data is enough to have a pretty good idea if the gear is bad or not, stellar, broken, or sub-par...

- ADC : E1DA Cosmos (Grade B), set to 4.7Vrms input. Minimum phase filter.
- Software : RMAA 6.4.5 PRO, Multitone Loopback Analyzer 1.0.15. After countless requests, I now measure unweighted THD+N with REW V5.20.7.
- Method : 8 runs for each test, then I choose the closest to the average. All regular tests are running 24bits / 44.1Khz except for Jitter and Multitone ones.
- Hidizs S9 Pro: BAL TRRS output at max volume, measured at 4.254Vrms @1Khz for both channels with a DMM.
- Main limitation : lack of load board to measure output at different impedances.
- Teasing for reviews to come : @IVX sent me a preproduction Cosmos APU, that is intended to improve both THD+N and AES DR accuracy in REW.
​

Summary​

Test	Results​	Rating​
Frequency response (from 40 Hz to 15 kHz), dB	+0.03, -0.23​	Very good​
Noise level, dB(A)	-122.7​	Stellar​
Dynamic range, dB(A)	122.4​	Stellar​
THD, %	0.00041​	Excellent​
THD + Noise, dB(A) (RMAA)	-103.1​	Excellent​
THD + Noise, dB (REW)	-104.6​	Excellent​
IMD + Noise, %	0.00060​	Excellent​
Stereo crosstalk, dB	-123.4​	Stellar​
IMD at 10 kHz, %	0.00050​	Excellent​

We are clearly landing in the desktop-class territory. It is in fact even better than many huge DACs sold by classic manufacturers. Main bottleneck here appears to be absolute THD, which is not the best I've seen and explains SINAD of about 105dB, despite superb Noise figures. It indeed performs several dB worse than the previous model measured by Amir. One hypothesis could be its output impedance being too low to be properly measured by the Cosmos... These are still excellent results, even more when talking about a dongle. Note that THD+N measured at Max volume matches specs quite accurately (0.0006%).​

REW FFT

​

​

Frequency response​

	Left​	Right​
From 20 Hz to 20 kHz, dB	-0.48, +0.03​	-0.48, +0.04​
From 40 Hz to 15 kHz, dB	-0.23, +0.03​	-0.23, +0.03​

​

Noise Level​

	Left​	Right​
RMS power, dB	-120.9​	-121.6​
RMS power (A-weighted), dB	-122.3​	-123.1​
Peak level, dB FS	-87.1​	-86.9​
DC offset, %	-0.0​	+0.0​

​

Dynamic range​

	Left​	Right​
Dynamic range, dB	+121.1​	+121.8​
Dynamic range (A-weighted), dB	+122.1​	+122.7​
DC offset, %	-0.00​	+0.00​

​

THD + Noise (at -3 dBFS)​

	Left​	Right​
THD, %	0.00046​	0.00036​
THD + Noise, %	0.00065​	0.00056​
THD + Noise (A-weighted), %	0.00074​	0.00065​

​

Intermodulation distortion (swept tones)​

	Left​	Right​
IMD + Noise at 5000 Hz,	0.00056​	0.00066​
IMD + Noise at 10000 Hz,	0.00041​	0.00050​
IMD + Noise at 15000 Hz,	0.00037​	0.00051​

​

Intermodulation distortion (SMPTE)​

	Left​	Right​
IMD + Noise, %	0.00061​	0.00058​
IMD + Noise (A-weighted), %	0.00042​	0.00039​

​

Stereo crosstalk​

	Left​	Right​
Crosstalk at 100 Hz, dB	-123​	-123​
Crosstalk at 1000 Hz, dB	-123​	-122​
Crosstalk at 10000 Hz, dB	-121​	-116​

In a nutshell : It nailed just about every test. I just noticed Left channel being constantly worse when looking closer at harmonic distortion and SMPTE IMD. Yet, variations are too subtle to be any kind of audible concerns.

That was analysis for fixed output at max volume. Let see how it behaves at lower levels:
​

Output levels​

Test​	0.9Vrms​	1.7Vrms​	2.7Vrms​	3.5Vrms​	4.25Vrms (Max)​
Frequency response (from 40 Hz to 15 kHz), dB	+0.03, -0.23​	+0.03, -0.23​	+0.03, -0.23​	+0.03, -0.23​	+0.03, -0.23​
Noise level, dB (A)	-112.4​	-117.2​	-120.2​	-121.2​	-122.7​
Dynamic range, dB (A)	112.4​	117.1​	120.0​	121.0​	122.4​
THD, %	0.00029​	0.00021​	0.00031​	0.00035​	0.00041​
THD + Noise, dB (REW)	-105.2​	-106.6​	-106.2​	-105.0​	-104.6​
IMD + Noise, %	0.00103​	0.00071​	0.00058​	0.00061​	0.00060​
Stereo crosstalk, dB	-112.4​	-117.4​	-120.7​	-121.7​	-123.4​

That is a bit unexpected. Usually, THD+N (in fact SNR/DR) goes down in parallel with digital attenuation. Here, we got THD going lower and lower, which still results in better THD+N despite the lower DR. Note that we do get 105.2dB SINAD even below 1 Volt ! As it is, I see no issue using the Hidizs S9 PRO as a competent preamp. Needless to mention, it should also be an acceptable headphone amp as well. Specs by the way are 200mW/32Ω (or 100mW/32Ω with SE output), that unfortunately, I cannot verify.​

​

THD + Noise (at -3 dBFS)​

REW FFT

​

Great figure, even at 0.9Vrms. Highest harmonic peak is now below -120dB, when related to 0dBFS level.​

Jitter
(48Khz, 1-24Khz bandwidth, 16 averages, 262K FFT)​

No comment. It absolutely nailed the J-Test.

Multitone 64
(192Khz, 20Hz-22Khz bandwidth, 10 averages, 262K FFT)​

As it does for multitone. Excellent job !

Conclusions​

My main regret here is to publishing some kind of "half review". Yes, I would have liked to test unbalanced output and more important, to find how the S9 PRO behaves relative to typical HF loads. Yet, just looking at primary results I've got out of this tiny unit, I cannot imagine it doing a bad job as a little headamp. Now, when seeing it like a regular DAC (USB in, BAL out, done!), it already performs way above its class (for both size and price) and got my easy recommendation, even for this purpose only !​

Flanker rating: Competent

 

[Matias]

Thanks, I always wondered how it measures.

 

[JanesJr1]

Hidizs S9 PRO (short) Measurements
​

View attachment 207259

My main regret here is to publishing some kind of "half review". Yes, I would have liked to test unbalanced output and more important, to find how the S9 PRO behaves relative to typical HF loads. Yet, just looking at primary results I've got out of this tiny unit, I cannot imagine it doing a bad job as a little headamp. Now, when seeing it like a regular DAC (USB in, BAL out, done!), it already performs way above its class (for both size and price) and got my easy recommendation, even for this purpose only !​

Flanker rating: Competent
​

[Broken record alert...]

I have been a (somewhat surprised) fan of the S9 Pro for months now, due to its graceful excellence at driving difficult DCA planar headphones with very low impedance (13 ohms) and not very good sensitivity. Subjectively, I cannot tell the difference between the S9 Pro and my Topping A50s amp even at loud SPL's in balanced mode. This initially surprised me, but the power numbers seem to support that conclusion.

It also drives my 300 ohm Senn HD6XX phones just as well.

I move location twice a day most days, and the S9 Pro has enabled me to be fully mobile with hard-to-drive headphones. The previous S9 I believe is one of the most powerful dongles in Amir's database, and this version is supposedly more powerful. StaticV3 has played around with preliminary numbers on S9 power-handling and I hope he finds something to chew on here.

I also have the comparably powerful E1DA 9038s G3, and it also handles a difficult load. However, it is prone to occasionally dropping out unexpectedly, and I have read one or two similar reports from others along the way. Subjectively, I also find its amp a bit darker, though not by a lot; YMMV.​

PS I see the comment about it running hot, but I use it constantly from my PC and have never once found it to be other than slightly warm at the extreme.

 

[ebslo]

Thanks, great to see this since most (all?) the high-performance dongles reviewed here are no longer available. I took a chance on one of these based on the s9 measurements, glad to see it holds up. The reviewer of the original s9 speculated that the somewhat low dynamic range of the s9 at low power may make it not well suited to sensitive IEM's, but I can report that with the s9 Pro I hear no hiss when mated to FiiO FD5's.

 

[JanesJr1]

Thanks, great to see this since most (all?) the high-performance dongles reviewed here are no longer available. I took a chance on one of these based on the s9 measurements, glad to see it holds up. The reviewer of the original s9 speculated that the somewhat low dynamic range of the s9 at low power may make it not well suited to sensitive IEM's, but I can report that with the s9 Pro I hear no hiss when mated to FiiO FD5's.

Same with my Ety's.

 

[Blumlein 88]

Do you have any info on what kind of power draw it has beyond a lot.

 

[IVX]

Anyway, the THD+N looks too high for that price tag IMO. Meizu HiFi DAC is better for $13

 

[JanesJr1]

Do you have any info on what kind of power draw it has beyond a lot.

Mfr. rating into 32 ohms is 100mW single ended and 200 mW balanced.

PS I believe there is a current limiter at 90 mA, which I believe is pretty good headroom for low impedance phones.

 

[ebslo]

Anyway, the THD+N looks too high for that price tag IMO. Meizu HiFi DAC is better for $13

DNR: Meizu = 103dB (ASR), S9 Pro = 122dB
THD+N: Meizu = -101dB (ASR), S9 Pro = -104dB

In addition, the S9 Pro distortion looks benign. The -108dB peak is the second harmonic which is much less audible than higher orders, and no other harmonic is above -120dB.

I can't speak to the value proposition, but it seems hard to justify saying the Meizu is better.

 

[ebslo]

Anyway, the THD+N looks too high for that price tag IMO. Meizu HiFi DAC is better for $13

It looks like Meizu lies on their specs; they claim DNR >120dB. I consider that disqualifying at any price.
Edit: It appears the Meizu can meet is specification under certain operating conditions.

 

[JanesJr1]

Anyway, the THD+N looks too high for that price tag IMO. Meizu HiFi DAC is better for $13

THD+N looks pretty darn good for 200 mW dongle output (take that, Meizu), and esp. at lower voltages. I don't know of another dongle that will get me 200 mW into 32ohms that will sound better for my even-lower-impedance, inefficient cans. E1DA 9038s comes close; I have it, it's even more powerful, but I prefer the tonality of the Hidizs amp, which consistently sounds subjectively more open and transparent to me.

As to the value proposition, If you have average headphones, you can probably get dongles that will work that are cheaper. I'm not so sure for hard-to-drive phones. The E1DA and Hidizs have roughly similar prices. For me, getting mobile daily with my beloved cans is very high-value, and I couldn't do it before.* At extremes, the Hidizs S9 Pro at $109 is certainly a saintly value compared to the popular AQ Dragonfly Cobalt at a current street price of $330, with its sh***y, underpowered amp section.**

* As I write this, I'm sitting in a nice armchair with my feet up 20 miles from my desktop dac/amp stack, listening to almost-distortion-free, high-resolution Brahms with superb separation and FR down to the deep sub-bass, thanks to this dongle, which makes me a happy man.

** I confess I bought one of those, before becoming a baptized ASR member. I tried it with my headphones to see what would happen and it was a major fail.

 

[ebslo]

Do you have any info on what kind of power draw it has beyond a lot.

Not super useful, but the USB subsystem reports max current = 100mA for this device, so that sets 0.5W as an upper bound.

 

[jasonhanjk]

Too bad there's no thd+n with 32 ohm load result.
Your report deserve an A with the current equipment that you posses.

 

[IVX]

DNR: Meizu = 103dB (ASR), S9 Pro = 122dB
THD+N: Meizu = -101dB (ASR), S9 Pro = -104dB

In addition, the S9 Pro distortion looks benign. The -108dB peak is the second harmonic which is much less audible than higher orders, and no other harmonic is above -120dB.

I can't speak to the value proposition, but it seems hard to justify saying the Meizu is better.

your data is simply wrong, who did measure Meizu HiFi DAC correctly may confirm DR 130db(A) and THD+N -110-115db@1kHz (no-load).
Why don't you guys care about distortions at loaded condition yet? No interest? Do you have plans to use portable DACs as desktop DAC only with 10kOhm input load?
PS: I know some pro-people suspect Cirrus do cheating with their CS43131/98 DACs.. That's why THD+N specs are so much worse than DR.
At the level -20-26dbfs these chips switch the gain to show you WOW DR, however, THD+N test sees that trick and reports real DR as 118-120db(A).

 

[JanesJr1]

Too bad there's no thd+n with 32 ohm load result.

hidizs says .0006% THD+N into 32 ohms balanced, .0012% single ended

 

[JanesJr1]

your data is simply wrong, who did measure Meizu HiFi DAC correctly may confirm DR 130db(A) and THD+N -110-115db@1kHz (no-load).
Why don't you guys care about distortions at loaded condition yet? No interest? Do you have plans to use portable DACs as desktop DAC only with 10kOhm input load?
PS: I know some pro-people suspect Cirrus do cheating with their CS43131/98 DACs.. That's why THD+N specs are so much worse than DR.
At the level -20-26dbfs these chips switch the gain to show you WOW DR, however, THD+N test sees that trick and reports real DR as 118-120db(A).

IVX, you're pretty familiar with the E1DA dongles as I recall, and they are an alternative to the Hidizs in this thread. Lately, I've been trying to get my E1DA 9038s G3 to work consistently. However, sometimes when I plug it in, or sometimes when I've paused for a while, it seems to go silent. I'm sure I read somewhere about this a while back but can't find it now. Do you know any reason why it would do this, or if I'm accidentally toggling one of its switching modes, or something? Is there some kind of protective circuit I might be triggering? I'd like to get it going, since it's supposed to be a little champ of a dongle... Thanks, if anything comes to mind.

 

[VintageFlanker]

IVX, you're pretty familiar with the E1DA dongles as I recall

He actually makes them...

Do you have any info on what kind of power draw it has beyond a lot.

Didn't "measure" that. I observed about 15 to 20% battery drop per hour with my (4080 mAh) Pixel 5 when playing music at full volume (I mean, off screen, playing music only, through UAPP).

I also owned the previous S9 and it sucked out about 10% per hour, when using SE output.

Do you have plans to use portable DACs as desktop DAC only with 10kOhm input load?

Why not?!

 

[Veri]

Anyway, the THD+N looks too high for that price tag IMO. Meizu HiFi DAC is better for $13

Love my Meizu, insane value. But I think it is less noise resistant than the competition. See for example small test here.
Should be fine on a battery-powered device though. But maybe less on a noisy desktop in combination with IEMs.

 

[Music1969]

the "PRO" now comes with ES9038Q2M from ESS.

Can you do a plot to show if it has the infamous ESS IMD 'hump' ?

 

[JanesJr1]

Anyway, the THD+N looks too high for that price tag IMO. Meizu HiFi DAC is better for $13

IVX, I didn't know you make the E1DA; I thought you were somehow in the audio industry and had sent the E1DA to Amir as a user. If you can give me some insight on the 9038s that's great, but I wasn't deliberately slant-drilling around your customer service function or puting you on the spot.