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Hidizs S9 Review (Headphone Adapter)

staticV3

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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.
The S9 Pro has a different headphone amp, so no. It is not just an S9 but with another DAC after the AKM factory burned down.
 

Glitch

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There were reports in the beginning of the Hidizs S9 being susseptible to phone radio interference. Have those been fixed in the S9 Pro?

@JanesJr1 do you use it with an Android phone?
 

JanesJr1

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I haven't used the Hidizs S9 Pro with any phone. I only use it with two PC's.

The current version has a different DAC chip from a different mfr and a different amp section from earlier S9 versions, and I am not aware of any radio interference issues with the current version.

Not much help, sorry...
 

Glitch

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I got the Hidizs S9 Pro and to answer my own question for others I have experienced zero phone radio interference whatsoever in 2 days with the OnePlus 8Pro phone. Just clean, pristine signal but there's noticeable bass quality degradation when driving Dan Clark Aeon RT 12.5Ohm from the 3.5mm jack starting at around 80% volume; it only gets decently loud at max but not very loud. I have it plugged into a portable headphone amp and it sounds pristine, resolving down to the extreme detail.

It gets hot but not dangerously so and the led is too bright but that's easily amendable.
 

Wunderphones

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Does it work OK with iPhone? I know some of the power-thirsty DAC/amps don't do well with iOS because of restrictions on the amount of current the OS will make available over the Lightning connector (or some similar concept, for those of you who like to correct people for no good reason...).
 

chi2

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@Glitch Will you try driving it balanced? That should give considerable more power and level. However, I am unsure about the bass quality as the output impedance will be doubled. Normally hardly an issue but with the very low impedance of the Aeon RT that might be different and lead to less damping and hence less control of the diaphragm. At least that would be the case with (dynamic) speakers :).
 

Veri

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However, I am unsure about the bass quality as the output impedance will be doubled. Normally hardly an issue but with the very low impedance of the Aeon RT that might be different and lead to less damping and hence less control of the diaphragm. At least that would be the case with (dynamic) speakers :).
Planars tend to not care about output impedance as long as there is enough current and the amp is not starting to clip.
 

Glitch

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I don't have balanced cables. :confused: Or an Apple phone. :rolleyes:
I saw a measurement of the DC Aeon RT impedance somewhere and it was dead flat at 12.5Ohm across the frequency spectrum.

There's a current limit on these dongles so on the lower impedance end balanced mode might not double the current output like you would expect, it really has to be measured to know for sure. And it will be good to see power vs. distortion plot with a 20Hz signal specifically because it will be different from a 1kHz signal. I don't see what frequency signal Amir uses for his power plots.
 

JanesJr1

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I got the Hidizs S9 Pro and to answer my own question for others I have experienced zero phone radio interference whatsoever in 2 days with the OnePlus 8Pro phone. Just clean, pristine signal but there's noticeable bass quality degradation when driving Dan Clark Aeon RT 12.5Ohm from the 3.5mm jack starting at around 80% volume; it only gets decently loud at max but not very loud. I have it plugged into a portable headphone amp and it sounds pristine, resolving down to the extreme detail.

It gets hot but not dangerously so and the led is too bright but that's easily amendable.
When you said you have attenuation of volume and bass quality of the Aeon RT phones using the 3.5mm jack, were you referring to the jack on the S9 Pro or the OnePlus phone?

The reason I ask is that if you were referring to the Hidizs, that is contrary to my own experience with the S9 and the DCA phones, where there is ample headroom for volume and bass....
 

Glitch

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@JanesJr1 my phone doesn't have a headphone jack, I'm talking about the Hidizs S9 Pro 3.5mm UNBALANCED jack. I didn't get the balanced cables unfortunately so I can't test them but they might have the same issue.

There's very apparent bass degradation before reaching max volume. I strongly suggest A/B comparing bass heavy tracks near full volume on Hidizs against a volume matched desktop headphone amplifier, I think it's very obvious.

I compare against the Topping NX7 headphone amplifier which is measured to deliver 1200mW @16Ω
 

JanesJr1

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@JanesJr1 my phone doesn't have a headphone jack, I'm talking about the Hidizs S9 Pro 3.5mm UNBALANCED jack. I didn't get the balanced cables unfortunately so I can't test them but they might have the same issue.

There's very apparent bass degradation before reaching max volume. I strongly suggest A/B comparing bass heavy tracks near full volume on Hidizs against a volume matched desktop headphone amplifier, I think it's very obvious.

I compare against the Topping NX7 headphone amplifier which is measured to deliver 1200mW @16Ω
Did all that a long time ago. I listen balanced. I've done many A/B's with SPL matched. I've heard the RT's when underpowered, but no problems with the Hidizs in months of listening, even with very challenging music. Sounds the same as Topping desktop with >2000 mW into 13 ohms, at least at reasonable listening levels (including Loud). On the single-ended jack, I've meant to make that same comparison, because I had linked StaticV3 to some third-party instrument measurements of the S9 Pro that indicated to him that at the 13 ohm impedance, the SE connection would behave the same as the balanced connection. (Not so at higher impedances, though.) But that was a tentative conclusion b/c he preferred to get more complete measurements, e.g. by Amir or someone similar. Anyway, I haven't gotten to the SE comparison yet. Sounds like you have, though, and the S9 was found wanting...
 

JanesJr1

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@JanesJr1 my phone doesn't have a headphone jack, I'm talking about the Hidizs S9 Pro 3.5mm UNBALANCED jack. I didn't get the balanced cables unfortunately so I can't test them but they might have the same issue.

There's very apparent bass degradation before reaching max volume. I strongly suggest A/B comparing bass heavy tracks near full volume on Hidizs against a volume matched desktop headphone amplifier, I think it's very obvious.

I compare against the Topping NX7 headphone amplifier which is measured to deliver 1200mW @16Ω
PS. the NX7 looks nice. Maybe why bother with the Hidizs if you've got something like that!
 

Glitch

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PS. the NX7 looks nice. Maybe why bother with the Hidizs if you've got something like that!
I made some unwise purchases namely getting the DC Aeon RTs with unbalanced cables and then thinking the Topping NX7 has a built-in DAC. I was going to return it but then I listened to it and was so impressed that I decided to keep it.
 

JanesJr1

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I made some unwise purchases namely getting the DC Aeon RTs with unbalanced cables and then thinking the Topping NX7 has a built-in DAC. I was going to return it but then I listened to it and was so impressed that I decided to keep it.
I made the same assumption about the DAC when I looked at it!

Does it work well as a line source from your phone or PC? You could sure drive the RT's with it. BTW my NFCA Topping desk amp has the same Pentaconn 4.4mm as your NX-7, and I found a nice cable for it at Hart Audio Cable for a lot less than what DCA charges for their a la carte cables with those Hirose connectors, and you can get swappable amp-end connectors (like both 4.4 mm and 2.5mm balanced). (That said, I use a 4.4mm to 2.5mm adapter to swap the cable between my desktop and the Hidisz.)

Anyway, I've been comparing my RT's (actually Drop/DCA Closed X's) to a new Noire and to my older HD6XX cans with the intent of sharing the results, and going through a long roster of A/B comparisons that will take me a while. This morning I plugged the Noire into the Hidizs just to see if it sounded the same as the RT's, and because of your earlier posting, I piped the most challenging music I can find through the Hidizs side-by-side with the Topping, and it sounded the same as the RT's (which you'd expect with similar specs anyway). That Hidizs S9 Pro will play anything. I like the HD6XX's in general, but I've found recordings that make the HD6XX's sound a little crappy due to bass distortion or hard-to-separate layering or both. However, with the RT's and the Noire, those recordings come through with headroom, low distortion, and fantastic separation, on both the Topping and Hidizs amps. Still in balanced mode, though, so far. I should've thought to dig out the SE cables.
 
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Glitch

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Yeah, I can't hear any distortion from the DC Aeon RTs. At high volume I feel a slight buzzing sensation but I think that's just my ears being overwhelmed by the sound pressure. They are helping me understand distortion in other speakers/headphones and equipment.

Here's an anecdote, I was using them to A/B compare the Topping NX7 against a decade old Aune 1X desktop DAC with a headphone amplifier and initially I thought the Topping had a bass problem while the Aune sounded more "musical". Listening more critically I discovered that there was bass ringing on loud thumps and while it was very apparent in the Topping it was also there with the Aune but it was getting masked very favorably by perhaps a higher noise floor. I figured the bass must be clipping earlier in the audio chain and eventually figured out it was from poorly implemented EQ in the Hiby player app so I lowered the pregain -6dB on EQ and that fixed the issue. I was able to debug a problem in my audio chain because I could hear what it was doing very clearly.
 

JanesJr1

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Yeah, I can't hear any distortion from the DC Aeon RTs. At high volume I feel a slight buzzing sensation but I think that's just my ears being overwhelmed by the sound pressure. They are helping me understand distortion in other speakers/headphones and equipment.

Here's an anecdote, I was using them to A/B compare the Topping NX7 against a decade old Aune 1X desktop DAC with a headphone amplifier and initially I thought the Topping had a bass problem while the Aune sounded more "musical". Listening more critically I discovered that there was bass ringing on loud thumps and while it was very apparent in the Topping it was also there with the Aune but it was getting masked very favorably by perhaps a higher noise floor. I figured the bass must be clipping earlier in the audio chain and eventually figured out it was from poorly implemented EQ in the Hiby player app so I lowered the pregain -6dB on EQ and that fixed the issue. I was able to debug a problem in my audio chain because I could hear what it was doing very clearly.
That's a great example!

For me, low distortion bass is like candy to my baby, but you've got to listen to it differently, with somewhat different values, especially if you're used to dynamic-driver bass with overtones, noise and so forth.

Planar bass can be deeper and more true to the recording, but at first listen can sound thinner in the upper bass / lower mids, or less "rich" compared to resonant bass. Drum strikes can be tonally very accurate, with a timbre that includes the strike but also the sonic ripple of the drumhead, while drum strikes on my HD6XX sound thicker, bolder (more "slam") but more like a hard "thud" than a true drum strike. The planars break out all the components of a recording with complex bass and lower-mids, while the HD6XX's tend to blend the details ... which is annoying to me in direct A/B comparison to the planars, but taken separately in a casual listen, can impart a tonal richness to the dynamic drivers. And so forth.

I find myself making similar comparisons between my Etymotic ER4's, with very detailed balanced-armature drivers, and ER2's, with dynamic drivers. (The ER4's, however, despite being more resolving, don't have the deep bass of planars, nor their EQ flexibility in those low FR bands.)
 
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Glitch

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Undistorted bass is like nothing I had ever heard before the DC Aeon RTs.
Even with well designed speakers the listening room will destroy the bass. I haven't heard it outside either because pro speakers never go below 50Hz. I think it has the potential to be a disruptive technology if somebody figures it out for subwoofers. It will outphase a few musical genres too.
 

Zoide

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Hi, I'm trying to understand how the power ratings work.

The review says the S9 reaches 110 mW with 32 ohm headphones. But for example I'm looking at a headphone (ES R-10) that has a sensitivity of 103dB/mW. 103 dB sounds about as loud as I'd even want to listen to headphones.

So does that mean that the S9's output is 110 times more powerful than what I would need for those headphones?

There's gotta be something I'm misunderstanding.

Thanks
 

Zoide

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Also, is the Hidizs S9 dongle (and presumably its S9 Pro successor) audibly indistinguishable from something like a Topping DX3 Pro+ or even a DX5?

If so, are the only reasons to get one of those the following?
  • Extra features (screen/knob/remote control/etc.)
  • You have some obscure, super hard-to-drive pair of headphones
Thanks
 
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