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strange SMSL M500 high 3rd harmonic

raif71

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Not at all. It means that the problem is only absent when both the left and right channels are playing the SAME audio. In other words, a mono source. The problem is there whenever you're playing a stereo source, which for most people is 99.9999999% of the time.
Agreed but without knowing the problem, most people are still enjoying the experience of listening to music on the su9 as well as with the m500, right? I can't confirm this on my own as I don't have these 2 units.
 

dpippel

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Agreed but without knowing the problem, most people are still enjoying the experience of listening to music on the su9 as well as with the m500, right? I can't confirm this on my own as I don't have these 2 units.
People listen to DACs with defects and underperforming specs all of the time and enjoy them, but that isn't really the point. The point is that S.M.S.L misrepresented (unintentionally as far as we know) the specs on both of these DACs, and people made purchasing decisions based on that incorrect data.
 
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nhatlam96

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Agreed but without knowing the problem, most people are still enjoying the experience of listening to music on the su9 as well as with the m500, right? I can't confirm this on my own as I don't have these 2 units.
Yes that is correct, we were enjoying it. Even Amir, who is a trained listener, enjoyed it.
Here is a quote from his review on the M500, where he stated that the fidelity was "excellent".
Headphone Listening Tests
I started my testing with Drop's Ether CX Mr. Speakers headphones. Here, I had plenty of volume but could stand playing at max volume. It was loud to be sure but I like to see more headroom than I had. That aside, performance was very good and clean to max volume as the measurements above show (i.e. lack of clipping).

I had a bit less headroom with Sennheiser HD-650 with less ability for "skull resonance" than I like to see. :) Fidelity otherwise was excellent though. To wit, I am still listening to the M500 using the HD-650 as I type this. Typically a good sign that I like what I am hearing.
I will look for an alternative now, maybe the Topping DX3 Pro V2? Sabaj D5 1/4 hp out is too weak.
 

raif71

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People listen to DACs with defects and underperforming specs all of the time and enjoy them, but that isn't really the point. The point is that S.M.S.L misrepresented (unintentionally as far as we know) the specs on both of these DACs, and people made purchasing decisions based on that incorrect data.
Yes that is correct, we were enjoying it. Even Amir, who is a trained listener, enjoyed it.
Here is a quote from his review on the M500, where he stated that the fidelity was "excellent".


I will look for an alternative now, maybe the Topping DX3 Pro V2? Sabaj D5 1/4 hp out is too weak.
Noted with thanks :)
 
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Hi all and thanks to Liu and Prof. Wolf for the find. I've been lurking here for awhile and was compelled to create a long overdue account. I for one bought the SU-9 based of this site and Amirs measurements. (no blame to ASR or Amir if they update the criteria in which tests are done) While I found no audible issue with the SU-9 I just couldn't NOT think about the issue it has. Regardless if the issue was audible for me, I couldn't live with my purchase. Having kept up with this thread from the start I have returned my SU-9. I feel S.M.S.L and Shenzhen Audio had some great opportunities to make some public statements to address this. I didn't feel confident the problem was going to be fixed for the average owner. I hope that isn't true but too much time had passed and no official info was given. The market has some really stiff competition and these type of incidents can get out of hand really quick and instilling confidence in customers is huge.

Purchased through Amazon outside of return window. It took some time with CS but they were great and approved the return.
 
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Yes that is correct, we were enjoying it. Even Amir, who is a trained listener, enjoyed it.
Here is a quote from his review on the M500, where he stated that the fidelity was "excellent".
As far I understood Smsl changed an OPamp and the software (after Amir's test) Amir's test was obviously with an error free device. I will monitor now the behaviour of smsl much more relaxed :cool:

What I also thought about... even I couldn't hear the issue doesn't mean I would not be able to hear it when I have a good one and this broken sample testing side by side. If you don't have a direct comparison you can't hear it except its completely fkd up... and this is not the case.
 
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solderdude

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As far I understood Smsl changed an OPamp and the software (after Amir's test) Amir's test was obviously with an error free device.
It's a conclusion I would not draw.
The FW was flawed from the start and is the only issue.
The opamp change isn't an audible issue at all and may have been the 'cheaper one' from the start of sales just not in the pre-production sample.
That sample was plagued with instability issues and was distortion related but Amir checked both channels at the same time so the issue may have been there all along.

Masking of 3rd harmonics is about -60dB at normal listening levels. The louder one plays masking gets even better.
The issue is down -80dB so well below masking levels using 'tones'.
With music I doubt this is even audible at all and is why no one hears this issue (also not Amir because he was not listening for it).

The issue exists, it should not be there. It will be 'fixed' in future versions for sure.
It is very measurable but below audible levels using music anyway.
No one, in any threads reported poor sound quality so no-one seems to have noticed.

Of course there are the golden ears that don't like the brand and stated they hated the sound and they will claim they heard it.
 
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solderdude

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He made just 1 post complaining about sound quality of Chinese HiFi products in general and mentioned he was disappointed yet again.

His comments were: The sound is flat, static.
He did not mention he heard distortion.
I would not classify this as a golden-eared person who can detect 3rd harmonic distortion at -80dB. ;)

Amir said this about the SU-9:

We have another great "instrument grade" DAC on our hands providing absolute transparency to the source beyond any threshold of human hearing. If you are hearing issues I suggest you either have your hearing examined, or learn to do a proper controlled test. Either way, what you hear is what is on your recording. Guaranteed!
 
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Somehow this is a forth and back here ...
Some ppl say how could you live with a 400€ device only having -75 SINAD and it affects all listening situatons, then others say whatever it is you will never hear any difference (even when applying the fix).

I am a bit lost now ... what for is the fix then? For measurement ppl having better plots? Please dont get me wrong ...
 

misterdog

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The joy of audio for a hobby, some cry FRAUD (then strangely wonder why the manufacturers do not engage on here).

Others say I cant hear any problem.

I wonder how many tens of thousands of other DACs there are out there, whose measurements are not 'acceptable'.

I have an SMSL M400 it is the best DAC I have ever heard, though I have no way to measure it.
 

Jimbob54

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Somehow this is a forth and back here ...
Some ppl say how could you live with a 400€ device only having -75 SINAD and it affects all listening situatons, then others say whatever it is you will never hear any difference (even when applying the fix).

I am a bit lost now ... what for is the fix then? For measurement ppl having better plots? Please dont get me wrong ...
We like car analogies. You buy one that should have a max speed of 180mph and 0-60 in 2.5 secs. You're happy with real world driving and think it's great.

Then the news lands that due to engine management software glitch its actually only ever had a max speed of 150 and 0-60 of 3.5 secs.

You'd want the fix but unlikely ever to notice its been applied?
 

artburda

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The joy of audio for a hobby, some cry FRAUD (then strangely wonder why the manufacturers do not engage on here).

Others say I cant hear any problem.

I wonder how many tens of thousands of other DACs there are out there, whose measurements are not 'acceptable'.

I have an SMSL M400 it is the best DAC I have ever heard, though I have no way to measure it.
If you want to sell products and you make claims regarding the performance and later on it‘s proven that those claims were untrue, then you can‘t just shut up and leave the customers in the dark. I mean you can, but who wants to make business with such a company in the long run? Is this how you build a good relationship with your customers? And why should it matter if there are potentially other dacs on the market that can‘t perform according to their specs? What kind of defense is that?
 

solderdude

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Somehow this is a forth and back here ...
Some ppl say how could you live with a 400€ device only having -75 SINAD and it affects all listening situatons, then others say whatever it is you will never hear any difference (even when applying the fix).

I am a bit lost now ... what for is the fix then? For measurement ppl having better plots? Please dont get me wrong ...
It is about meeting specs. Both M500 and SU9 have good specs but these are only good when tested with both channels having the same signals at the same time. This is how @WolfX-700 and @amirm measured them. Full pass.

@liu had a point that those measurements didn't catch this particular issue. Should both have measured the channels separately (requires a different digital input signal) then measurements would have shown this issue and am quite certain Amir would have made an issue of it and not recommended it.

So the issue is specs are not met with stereo signals (which all music, except mono is) while other models seem to not have this issue.
It is found serious enough for SMSL to update the FW. I guess they are still deliberating how to implement this with devices already out there.

Then there is the question of audibility. No one seems to have heard it. Science says it probably is barely audible at not too loud levels using test tones. It would appear to be inaudible when listening to music.
@liu may have stumbled upon this. He did not state he heard 'something' and investigated it but may have noticed it doing a channel separation test ?
It is not visible in regular crostalk tests as the issue happens in the channel with the stimulus while crosstalk tests only look at signals in the silent channel. That looked fine (as seen in WolfX700 plots).
As @liu used ADI2 and REW and not APx555 that might have been why @liu spotted it and the AP555 owners were left in the dark as it were.
 
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raif71

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The joy of audio for a hobby, some cry FRAUD (then strangely wonder why the manufacturers do not engage on here).

Others say I cant hear any problem.

I wonder how many tens of thousands of other DACs there are out there, whose measurements are not 'acceptable'.

I have an SMSL M400 it is the best DAC I have ever heard, though I have no way to measure it.
You mean measured like Liu did with the m500?
 
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It is about meeting specs. Both M500 and SU9 have good specs but these are only good when tested with both channels having the same signals at the same time. This is how @WolfX-700 and @amirm measured them. Full pass.
This was the info I obviously missed and misunderstood. I slowly get to a full picture. I will deeply think about what to do until monday. If I send it back or not ... Thanks for that!
 

solderdude

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Perhaps wait till there is an official response on how they are going to 'solve' this for current users. That is if there is still a 'return window'.

It's up to each individual owner to see if they can live with this, most likely inaudible, issue that no one really noticed while listening to music.
 

ZööZ

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Didn't wade through the whole thread so just wondering if this finding has any implications on how gear should be tested in the future, perhaps add a single channel test to the repertoire, or is this such an outlier it would be unnecessary?
 

aandres_gm

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We like car analogies. You buy one that should have a max speed of 180mph and 0-60 in 2.5 secs. You're happy with real world driving and think it's great.

Then the news lands that due to engine management software glitch its actually only ever had a max speed of 150 and 0-60 of 3.5 secs.

You'd want the fix but unlikely ever to notice its been applied?
To complete your analogy, we could add another detail: the max allowed speed (aka limits of human hearing) in the country is 70mph. You couldn't ever reach the real max speed of 150mph, let alone the advertised max of 180mph, but, as the Germans would say: es geht ums Prinzip. Customers should get what was advertised, even though they may not need that in the first place.
 
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