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Hidizs S9 Review (Headphone Adapter)

ZolaIII

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@Domenico what exactly do you need? You divide 300 Ohm's with two and you have output at 600 Ohm's. You really need to know only how much it outputs in Volts.
Learn to use calculator.
Then learn V to dB.
Now you can use IMD graphs when presented.
As I remember Amir made couple videos (on YouTube) what measurements are and how to understand them.
Always buy an amp with 2x headroom in W/V (6 dB) than what you need.
 

Vik

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Update to my previous posts having trouble to get the S9 to work with macOS Big Sur.

I emailed back and forth with the company -- they are very quick to respond and are very helpful and friendly: Great customer support! In the end they send me a download link for two Windows 10 executables (".exe") and a firmware file (".hex") and an installation document (MS Word, ".doc"). The installation document is needed, it is not simply a "double-click" action—read the manual before attempting to install the firmware update.

Steps:
1. Install a programme under Windows 10 ("SXW driver WHQL_20200902.exe”)
Do you know if there is a solution for Mac users who don't have access to a Windows computer? And – does anyone here know if these problems are common on the pro version as well?
 

staticV3

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Do you know if there is a solution for Mac users who don't have access to a Windows computer? And – does anyone here know if these problems are common on the pro version as well?
Both Parallels and Bootcamp should work fine to flash a new firmware to the S9.
 

JanesJr1

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A review of the S9 Pro with specs and measurements is at https://hiendportable.com/hidizs-s9-pro-english-review/ .

To put the figures into perspective, there is another thread that questions whether the S9 Pro can drive low impedence headphones like the DCA Aeon RT, which has the same hardware and specs as the Drop/DCA Aeon Closed X. I put the following observations there:

"I note the author's mention of a 90 mA limiter that pegs balanced output at 130 mW into 15 ohms and 230 mW at 33 ohms. There is also mention of higher temperatures at high volumes. I have used it a lot, including high volume, and have noticed at most mild warmth. That's with the unit enclosed in a plastic shell/clip supplied OEM plus one long side covered with velcro. In practical use, I don't see a problem at all based on my experience.

"However, I get these figures; let me know if it doesn't look right. With sensitivity of 91 dB for the DCA Aeon RT, and 110 dB spl that calculates to required power of 80 mW (well below 130mW spec mentioned above), 1.06 volts (well below >2V measurement) and 75.6 mA current required (vs. 90 mA spec with limiter). So this would confirm the ability of the dongle to power the DCA phones up to 110 SPL in balanced mode; any higher SPL and the limits seem to be reached. 110 DBSPL seems good to me!

I also changed the impedance to 300 in the headphone power calculator (simulating say. HD650 phones), and the power requirement was easily met; but the required voltage went up to nearly 5 VRMS, and I'm not sure I understand the technical implications of that.

I look forward to staticV3's comments.
 
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staticV3

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Scope measurements are better than nothing. I'll make a graph using them for comparison.
 

staticV3

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Here's the graph using measurements from hiendportable:
Max Voltage vs Load-4x_foolhardy_Remacri.png

At 13Ω you're looking at ~1.15Vrms regardless of which jack you use.

The Aeon RT Closed has a sensitivity of 97.4dB/Vrms as measured by Amir.
With the S9 Pro, you can expect 98.6dB SPL peak.
 

JanesJr1

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"The Aeon RT Closed has a sensitivity of 97.4dB/Vrms as measured by Amir.
With the S9 Pro, you can expect 98.6dB SPL peak."

staticV3, I follow your numbers from Amir's RT review at 677 mV. However I used Drop's published spec of 91dB(mv) sensitivity for the Closed X phones.

I understand a prejudice in favor of using our own measurements, but I am not savvy about how we do those measurements or the accuracy. I also do not know if there is absolutely identical hardware crossing from RT to Closed X. Also, looking globally at Amir's RT review, he found the RT's were not under strain (beyond very minor distortion) until somewhere between 104 and 114 dB SPL, which seems noticeably higher than 98.6..

I'm not arguing: you know a lot more than me technically. I'm just kicking the tires on uncertain or conflicting measurements. It may not make that much difference, anyway. The dongle works very well for me with the Closed X's and I;ve listened to it a lot, with every kind of music. I don't hear any obvious clipping or bass-pumping as long as I have a clear signal with good network bandwidth (I only have streaming sources most of the time, and one ISP I use for long houirs at the office can be audibly bandwidth-limited at times.) If there is any problem, it might be only with transient peaks.
 
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JanesJr1

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Here's the graph using measurements from hiendportable:
View attachment 198154

At 13Ω you're looking at ~1.15Vrms regardless of which jack you use.

The Aeon RT Closed has a sensitivity of 97.4dB/Vrms as measured by Amir.
With the S9 Pro, you can expect 98.6dB SPL peak.
With respect to the Hidizs S9 graphic, help me understand how to interpret it. Am I correct that with 13 or 14 ohm load for the DCA phones, it doesn't matter whether balanced or single-ended connections are employed? (Because of the divergence of Balanced and SE Vrms only at higher impedence values? .. Please tolerate my literal-mindedness; I'm just trying to learn the basics for the first time.)
 

Jimbob54

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"The Aeon RT Closed has a sensitivity of 97.4dB/Vrms as measured by Amir.
With the S9 Pro, you can expect 98.6dB SPL peak."

staticV3, I follow your numbers from Amir's RT review at 677 mV. However I used Drop's published spec of 91dB(mv) sensitivity for the Closed X phones.

I understand a prejudice in favor of using our own measurements, but I am not savvy about how we do those measurements or the accuracy. I also do not know if there is absolutely identical hardware crossing from RT to Closed X. Also, looking globally at Amir's RT review, he found the RT's were not under strain (beyond very minor distortion) until somewhere between 104 and 114 dB SPL, which seems noticeably higher than 98.6..

I'm not arguing: you know a lot more than me technically. I'm just kicking the tires on uncertain or conflicting measurements. It may not make that much difference, anyway. The dongle works very well for me with the Closed X's and I;ve listened to it a lot, with every kind of music. I don't hear any obvious clipping or bass-pumping as long as I have a clear signal with good network bandwidth (I only have streaming sources most of the time, and one ISP I use for long houirs at the office can be audibly bandwidth-limited at times.) If there is any problem, it might be only with transient peaks.
Didn't you have a string of posts about the S9 Pro running out of juice with the Aeon, tweaking eq to pull back on the bass response?

Edit 1 Also, static worked out the peak volume you could expect from the S9 Pro on those cans, nothing about the distortion characteristics of the headphones themselves. Apples and oranges


Edit 2 the drop specs show 91db/mw, static has used 97dB /V. In an ideal world one would be able to reconcile those 2 figures but I can't, 97db/v at 13 ohms equals 78 db/mw
 
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JanesJr1

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Didn't you have a string of posts about the S9 Pro running out of juice with the Aeon, tweaking eq to pull back on the bass response?

Edit 1 Also, static worked out the peak volume you could expect from the S9 Pro on those cans, nothing about the distortion characteristics of the headphones themselves. Apples and oranges


Edit 2 the drop specs show 91db/mw, static has used 97dB /V. In an ideal world one would be able to reconcile those 2 figures but I can't, 97db/v at 13 ohms equals 78 db/mw
Re: headphone headroom: I did have the series of posts on weak response, and later discovered that most of it (not all) was related to network bandwidth. I spend long hours at my office, and bandwidth sometimes contracts enough to cause audible bass pumping and other symptoms. Also, I found that an ISP-installed VPN with limited bandwidth automatically restarts after a period, even if I defeat it. The come-and-go nature of the bottleneck fooled me for a while into believing it was either a power issue or a slam issue. I mentioned all this in a post, and tried to delete earlier posts. I didn't know how to measure network throttling except by listening, so a short diary of listening times and SQ proved the point to my satisfaction: the problem always cleared up by the middle of the evening and on weekends.

I still hear some lack of 'slam', especially at low/moderate volume levels, and think of it as a headphone attribute but not specifically a function of dongle headroom, because on my home network, the dongle sounds just about as good as my desktop amp does at work on weekends. But I like the positives of the headphones more than I dislike the slam weakness.

Re: Peak Power: Help me on the technicalities: the "peak volume" static calculated based on Amir's sensitivity at 97, I assumed was either the peak power before unacceptable distortion starts, or perhaps in this case, the max power due to the 90 mA limiter in the dongle. Unless I'm mistaken (and I may be, correct me if so), Amir's power ratings are a function of DBSPL and distortion (transducers) or distortion and impedance (electronics). His observations on the DCA phones was that they acccepted significantly higher SPL's than statics 99dB with grace (i.e. with low distortion). In my calculations, based on the published sensitivity of 91, I had figured that SPLs well over 100 dB should be possible with acceptable distortion.

Where I may be confused is on what the "peak" power represents: a lid, beyond which the amp cannot go; or simply the crossover point to distortion caused by amp clipping and/or transducer distortion. I'm new to the math and the electronics, and I would like to get this down.
 
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staticV3

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hiendportable's measurement are very limited and so we're definitely missing context. All we have is the load and what voltage they were able to "achieve" at that load. Ideally we would have THD+N vs Vrms graphs, but more specialized equipment is necessary for those.
Then we could tell if the ~1.15Vrms @13Ω is "at the knee", at 1% THD+N, at 0dBFS, or whatever.
For now it's the best we have.

As for DCA's official specs, I wouldn't trust them. Despite DCA being science-based, they have a very poor track record publishing specs. Many models don't get any official specs, some models have conflicting specs, and in the rare instance that there are consistent sensitivity numbers, 3rd party testers just cannot get close to them.
That coupled with a confusing product portfolio (Aeon 2 Closed vs Aeon Flow 2 Closed? Aeon RT Closed vs Aeon Closed X?) makes the entire situation quite a mess to figure out.
I'd say stick to independent measurements wherever you can.

Amir measured .677Vrms to reach 94dB SPL at 425Hz with the Aeon RT Closed.

Using hiendportable's data points we can then extrapolate that while 1.35Vrms were "achieved" at 15Ω, that number would drop to about 1.15-1.2Vrms at the 13Ω of the Aeon RT.
Going from 0.677Vrms to 1.15Vrms is a 4.6dB increase in sound pressure, ergo 94+4.6=98.6dB SPL can be "achieved" with the S9 Pro (again, lack of context), though the headphone itself obviously has a lot more to give, amplification permitting.
 

JanesJr1

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hiendportable's measurement are very limited and so we're definitely missing context. All we have is the load and what voltage they were able to "achieve" at that load. Ideally we would have THD+N vs Vrms graphs, but more specialized equipment is necessary for those.
Then we could tell if the ~1.15Vrms @13Ω is "at the knee", at 1% THD+N, at 0dBFS, or whatever.
For now it's the best we have.

As for DCA's official specs, I wouldn't trust them. Despite DCA being science-based, they have a very poor track record publishing specs. Many models don't get any official specs, some models have conflicting specs, and in the rare instance that there are consistent sensitivity numbers, 3rd party testers just cannot get close to them.
That coupled with a confusing product portfolio (Aeon 2 Closed vs Aeon Flow 2 Closed? Aeon RT Closed vs Aeon Closed X?) makes the entire situation quite a mess to figure out.
I'd say stick to independent measurements wherever you can.

Amir measured .677Vrms to reach 94dB SPL at 425Hz with the Aeon RT Closed.

Using hiendportable's data points we can then extrapolate that while 1.35Vrms were "achieved" at 15Ω, that number would drop to about 1.15-1.2Vrms at the 13Ω of the Aeon RT.
Going from 0.677Vrms to 1.15Vrms is a 4.6dB increase in sound pressure, ergo 94+4.6=98.6dB SPL can be "achieved" with the S9 Pro (again, lack of context), though the headphone itself obviously has a lot more to give, amplification permitting.
Really helpful. I understand the math to get to 98.6 dB, but I am unclear what it represents in the physical world: is that SPL a ceiling controlled by the 90 mA limiter? The crossover point to (a) clipping/amp distortion; or (b) headphone distortion?
 

staticV3

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Really helpful. I understand the math to get to 98.6 dB, but I am unclear what it represents in the physical world: is that SPL a ceiling controlled by the 90 mA limiter? The crossover point to (a) clipping/amp distortion; or (b) headphone distortion?
We know the headphone can do more. Amir's distortion measurements show that.
As for what limits the S9 Pro to ~1.15Vrms at 13Ω, I cannot tell without more detailed measurements.
 

deniall83

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Would this drive the Dan Clark Aeon RT? I'm looking for a portable solution for these headphones.
 

staticV3

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Would this drive the Dan Clark Aeon RT? I'm looking for a portable solution for these headphones.
Your best chance at driving the Aeon RT on the go is either the E1DA 9038S, or the Topping NX7.
The 9038S will do ~650mW per channel @13Ω @1% THD+N -> 106.6dB SPL peak.
The NX7 will do about 1.1W per channel @13Ω -> 109dB SPL peak
For comparison, the S9's balanced 2.5mm output can only do ~55-60mW @13Ω -> ~96.5dB SPL peak.

In terms of perceived loudness, you can think of the 9038S as 100%, the NX7 as 118%, and the S9 as 50%.
 

JanesJr1

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The S9 Pro (not S9) running in balanced mode has plenty of power for the RT. I've been using it side-by-side with Topping A50s desktop amp and E1DA 9038s G3 dongle for several months. with many A/B comparisons. The S9 Pro sounds great, and is hard to distinguish from the powerful Topping desktop amp even with demanding material, such as complex orchestral music or electronica with lots of sub-bass. The E1DA 9038s in balanced mode also has enough power, but the amp section seems to generate a slightly darker, less-open tonality. (You might not notice it except in A/B comparisons, and even if you did, you might be able to EQ it.) I'm familiar with what the RT's sound like with either inadequate or simply not-quite-ideal power sources. However, either of these two dongles will work.

I don't know if balanced mode is necessary, but it may help. That said, I pointed staticV3 to some independent measurements of the S9 Pro that suggest to him, tentatively, that at the lowest impedances (like the RT) balanced mode may not help. If true, the S9 Pro single-ended would work just as well. Check with him if more measurements (e.g. on ASR) appear. Running balanced mode does mean a balanced headphone output and a balanced cable with DCA-style Hirose connectors from someone like Hart Audio Cable (much cheaper than DCA; I like the ones I've gotten there). The S9 Pro has both balanced and single-ended jacks; the E1DA 9038s runs only balanced, but there is the single-ended 9038d as an alternative.

If I can get a chance, I'll try comparing the S9 Pro A/B in single-ended mode to the Topping in single-ended mode and the E1DA in balanced mode (since it only runs in balanced mode).

[Sorry, I just noticed that this thread is headlined only for the S9, not the S9 Pro. If this post is a distraction, sorry!]
 
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deniall83

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The S9 Pro (not S9) running in balanced mode has plenty of power for the RT. I've been using it side-by-side with Topping A50s desktop amp and E1DA 9038s G3 dongle for several months. with many A/B comparisons. The S9 Pro sounds great, and is hard to distinguish from the powerful Topping desktop amp even with demanding material, such as complex orchestral music or electronica with lots of sub-bass. The E1DA 9038s in balanced mode also has enough power, but the amp section seems to generate a slightly darker, less-open tonality. (You might not notice it except in A/B comparisons, and even if you did, you might be able to EQ it.) I'm familiar with what the RT's sound like with either inadequate or simply not-quite-ideal power sources. However, either of these two dongles will work.

I don't know if balanced mode is necessary, but it may help. That said, I pointed staticV3 to some independent measurements of the S9 Pro that suggest to him, tentatively, that at the lowest impedances (like the RT) balanced mode may not help. If true, the S9 Pro single-ended would work just as well. Check with him if more measurements (e.g. on ASR) appear. Running balanced mode does mean a balanced headphone output and a balanced cable with DCA-style Hirose connectors from someone like Hart Audio Cable (much cheaper than DCA; I like the ones I've gotten there). The S9 Pro has both balanced and single-ended jacks; the E1DA 9038s runs only balanced, but there is the single-ended 9038d as an alternative.

If I can get a chance, I'll try comparing the S9 Pro A/B in single-ended mode to the Topping in single-ended mode and the E1DA in balanced mode (since it only runs in balanced mode).

[Sorry, I just noticed that this thread is headlined only for the S9, not the S9 Pro. If this post is a distraction, sorry!]
Thanks! I'm not sure there even is a regular S9. Certainly no mention of it on the Hidizs website anyway.
 

JanesJr1

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Thanks! I'm not sure there even is a regular S9. Certainly no mention of it on the Hidizs website anyway.
Someone correct me if I'm wrong, but I think the S9 was an equivalent product before a big semiconductor plant fire. I think the story is that Hidizs, like some other firms, had to find an alternative chip and the S9 Pro was born as the successor to the S9 that way.
 
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