SMSL M400 Balanced USB MQA DAC Review

[Mr.Ian]

Output/imput impedance is one ratio that does warrant attention especially with passive pre amps and some pro audio gear. Fortunately i am feeding balanced into 300k. And its a recent model m400.

 

[A Surfer]

I listen to music not specifications, if one piece of equipment gives me a more pleasurable listening experience than another i prefer it.

Lindt excellence 100% chocolate could claim to be more techinically superior to Cadbury's dairy milk chocolate because it has a higher % of cocoa but i prefer Cadbury's.

If you prefer techical specs or believe everything sound/tastes the same so be it, i am not knocking your views i just dont subscribe to them.

Please do remain in the community, but know one thing, this community is about knocking the views that pretend to be evidenced based when really they are all about expectation bias. If you want an echo chamber where everybody agrees with you that they to can hear impossible to detect differences, head-fi might be a better fit. Saying that, really we aren't mean-spirited or wishing to drive people away, but we will call people on their assumptions and ask for and encourage the collection of evidence.

 

[misterdog]

Please do remain in the community, but know one thing, this community is about knocking the views that pretend to be evidenced based when really they are all about expectation bias.

He merely expressed a preference, no where does he claim that one is better than another except to his own ears/room/system.

I am running an m400 in low dispersion mode, its amazing, i much prefer it to x16, d50, d70s, d90, e30,. I DONT subscribe to they all sound the same view, well not on my set up anyway.

I also PREFER the sound of my M400 to that of my X16.

 

[A Surfer]

He merely expressed a preference, no where does he claim that one is better than another except to his own ears/room/system.



I also PREFER the sound of my M400 to that of my X16.

And how did you go about determining this reported sound difference? Let me guess, you used your ears.

 

[A Surfer]

He merely expressed a preference, no where does he claim that one is better than another except to his own ears/room/system.



I also PREFER the sound of my M400 to that of my X16.

As for the preference, I never said preferred either, I suggested that there was an expectation bias in play, no direction was stated.

 

[misterdog]

My expectation bias was that the X16 would 'sound' better, that is why I bought it, I prefer the M400.

AKM uses different technology than ESS in the chip, If you can use the full 5.3V output of M400 on XLR (I do) it has better SINAD than X16.

Though some are outraged that the M400 has a 5.3V output when 4.0 V is 'standard' (even though no such standard exists). So Amir tests all DACs at 4.0V to give a 'level' playing field.

M 400

X16

Does the extra 2 dB in SINAD show a reason for our preference, which is actually measured ?

 

[Veri]

Does the extra 2 dB in SINAD show a reason for our preference, which is actually measured ?

Well. The most likely explanation is that 5.3V is obviously much higher/louder.

 

[Lupin]

Well. The most likely explanation is that 5.3V is obviously much higher/louder.

^This

121 -> 123 db SINAD is in noway an audible difference nor concern.
imho there's no point in spending more money on a DAC just to get 2 or 3 db of extra SINAD while every half decent DAC now days already scores north of 118 db SINAD. I much rather spend that money towards features, connectivity or more pleasing aesthetics. Areas where that money actually makes a noticeable difference.

 

[A Surfer]

Amazing, the poster proves my point and confirms that it was expectation bias. I am not sure why it confuses people how such bias actually works. The fact that misterdog expected there to be an audible difference at all, doesn't matter which device, is the expectation bias. On top of it how one can fail to acknowledge the almost certain impact of the greater output voltage from the M400 (assuming that he didn't change it) is equally baffling.

 

[misterdog]

Amazing, the poster proves my point and confirms that it was expectation bias.

Congratulations. Glad I was able to help you.

On top of it how one can fail to acknowledge the almost certain impact of the greater output voltage from the M400 (assuming that he didn't change it) is equally baffling.

Or maybe my Topping Pre 90 has better performance with the higher voltage output of the M400 ?

Gain matching is seldom mention on this forum, many choose to stop at the -120dB 'threshold of hearing' and think anything other is nonsense.

Using a higher output level I can then run my Benchmark AHB2 in low gain mode, once again superior measured performance, but as you say it's all bias expectation - or maybe not.....

Then some would say that my previous amps, Hypex NC400 mono's would sound the same, and be wrong again.

 

[A Surfer]

Congratulations. Glad I was able to help you.



Or maybe my Topping Pre 90 has better performance with the higher voltage output of the M400 ?

Gain matching is seldom mention on this forum, many choose to stop at the -120dB 'threshold of hearing' and think anything other is nonsense.

Using a higher output level I can then run my Benchmark AHB2 in low gain mode, once again superior measured performance, but as you say it's all bias expectation - or maybe not.....

Then some would say that my previous amps, Hypex NC400 mono's would sound the same, and be wrong again.

And what evidence (and please do not use sighted listening testing) as evidence that they would be wrong?

 

[misterdog]

this community is about knocking the views that pretend to be evidenced based when really they are all about expectation bias.

Though expectation bias can be both positive and negative, if you are driven by purely objective 'fact' you will know that at best human hearing can only hear 20Hz to 20Khz.

Why then does Amir measure the noise from power supplies outside of the audio band ?

Could it be that that this noise bleeds into the audio band ? Could it be that this is the reason that I subjectively have much greater preference for my AHB2 to my previous NC400's ?

At Benchmark, if we can measure an artifact, we don't try to determine if it is low enough to be inaudible, we simply try to eliminate it.

AUDIBLE ARTIFACTS THAT ELUDE TRADITIONAL MEASUREMENTS​

To date, one of the most elusive artifacts that we have encountered is the issue of intersample overs. These are intersample peaks that exceed 0 dBFS while the sample values themselves never exceed 0 dBFS. These peaks can reach +3 dBFS and can cause DSP overloads in fixed-point PCM sigma-delta converters and sample rate converters. It is important to note that the DSP overloads are caused by the finite boundaries of the fixed-point math and not by some inherent defect in PCM or in the upsampling process.

Listening vs. Measuring

At Benchmark, listening is the final exam that determines if a design passes from engineering to production. When all of the measurements show that a product is working flawlessly, we spend time listening for issues that may not have shown up on the test station. If we hear something, we go back...

benchmarkmedia.com

Fixating on perceived 'known' science can cause just as much expectation bias for some.

SINAD simply combines all of the unwanted parts of the signal into one number, it has trouble capturing what we hear. As early as 1950, there were suggestions to improve the calculation to better match subjective sound quality, but ultimately simplicity and inertia won out, and SINAD remains the same to this day.

Evaluating SINAD - Why it's NOT important

Blaine Lacross and Andrew Park examine SINAD, a popular index commonly used to evaluate amps and DACs. In this article, they explain why it's not important

www.headphones.com

So I am more than happy with the -138dB of distortion from my M400 as it allows headroom for the science that we have yet to understand and allows for the fact that music is not steady state, yet measurements of devices under test are.

Did I mention that my audiophile friends and myself have over 100 years of listening, and reading about listening experience between us. So I think that experience gives us a little more insight than just 'expectation bias'.
One of my friends has heard more equipment than I have had hot dinners, he also designs and builds audio kit, he says that my system is as good as it is possible to get.

So on that basis I say that I much prefer the AHB2 to the Hypex NC400 and the M400 to the X16.
But that is my opinion (and others) in my room to our ears.

 

[A Surfer]

Good lord no, it doesn't matter how much experience you have listening, if anything that makes it worse. You really need to accept that you, and everybody you know are still subject to the same psychological constraints that dog the rest of the species. Bummer, but it's true. Even though you have lots of experience with sighted listening testing.

 

[SuicideSquid]

Good lord no, it doesn't matter how much experience you have listening, if anything that makes it worse. You really need to accept that you, and everybody you know are still subject to the same psychological constraints that dog the rest of the species. Bummer, but it's true. Even though you have lots of experience with sighted listening testing.

This argument about "listening vs. measurement" can be easily resolved through one simple method:

Double-blind testing.

As soon as you hide what device is being listened to from both the listener and the person administering the test, it turns out all these devices that measure the same sound the same.

 

[Veri]

Did I mention that my audiophile friends and myself have over 100 years of listening, and reading about listening experience between us.

 

[misterdog]

Objective absolutists need to accept that there is more to music enjoyment than pure static measurements.
Did you read the listening V measuring article by John Siau vice president of Benchmark, he produces the best measured amplifier in this forum yet accepts that purely measured testing has flaws.

Yet pure objectivist based audiophiles refuse to accept such heresy, as there is no other god than mine.

As soon as you hide what device is being listened to from both the listener and the person administering the test, it turns out all these devices that measure the same sound the same.

But the AHB2 measures 8dB SINAD better than the NC400, which confirms my subjective findings.
The M400 has 2dB better than the X16.

Awaits the debate that measurements ( static test) have no meaning beyond a certain level (see out of band power supply graph above).

 

[Lupin]

So I think that experience gives us a little more insight than just 'expectation bias'..

That statement just proves that you don't understand the concept of expectation bias or human psychology in relation with how we humans perceive audio.

No, you're not above it. You're just as much influenced by expectation bias as any other person. You're so called "experience" is completely irrelevant and meaningless in this matter be it 100 years or 1000000 years.

 

[misterdog]

My Quad 989ESL's have best measured distortion of <0.15% , so I could plug in my old 1980's Yamaha amplifier and my Audiolab MDAC and the sound would be the same as my M400 and AHB2 then, as both my vintage devices have that same measured level of distortion.

Simple measured science.

If anyone bothered to read the article from Benchmark, they would see the extraordinary levels they go to, with their ABX listening tests.

We match levels to a precision of +/- 0.1 dB when conducting listening tests. Slight differences in levels can be noticeable and these differences can skew the tests, especially when we are listening for small differences.

It would appear though that some cannot go past the words 'listening' or 'subjective' without turning into Pavlov's dog and having to type the words 'expectation bias' on a forum.
Shame really as this excludes many from participating on this forum.
If you read my posts you will notice that my device choices were primarily based upon measured performance - so I agree with you, just not to the level of absolutism.

Maybe one day science will be able to understand black holes, the missing mass of the universe and how the human brain works.
Until then 'we' just have to accept that science knows all there is to know about listening to music.

I think I understand human psychology now, blinkered.

 

[SuicideSquid]

But the AHB2 measures 8dB SINAD better than the NC400, which confirms my subjective findings.
The M400 has 2dB better than the X16.

No it doesn't. Your ears are simply not that sensitive - no one's are. That's the point everyone's been trying to make to you - you're misunderstanding the measurements and human physiology.

If you're that confident in your ability to hear differences below the threshold of hearing, do it blinded. If you switch back and forth between the AHB2 and NC400 fifty times and can tell which is which 80% or more of the time, I'll believe you. Likewise for the M400 and X16. However, I'd put a lot of money on you doing no better than random chance in a properly conducted blind test.

The simple fact of the matter is that your senses are not as sensitive as the best measurement devices - it doesn't matter whether you're talking about hearing or vision. It is the height of arrogance to think that you've got magic ears. You don't. If the only difference between two devices is 2dB of noise below the threshold of hearing, you can't hear the difference between them. If you want to prove otherwise, do so in a double-blind test.

 

[misterdog]

It is the height of arrogance to think that you've got magic ears.

Please show where I have mentioned that I assume that I have.


So where is Benchmark's ABX testing system lacking in scientific rigour ?

Why does Amir measure measure out of band noise in amplifier power supplies ?.

Rather than constantly attacking me show some measured science to support your absolute objectivism. Surely the proven science has simple answers to my often asked questions.