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Can you review a Synchro-Mesh S/PDIF re-clocker?

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amirm

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What you are telling me is that I'm imagining this or hallucinating. I'm afraid not. If I am cold, you can tell me I'm not cold, but my senses and shivering are telling me that I'm cold. I trust my senses.
If you touch a metal in your home, it will feel colder than fabric. You probably know that the temp of the metal is the same as the fabric. The metal feels colder because it draws away the heat from your hand. The conclusion then that the metal is colder than fabric would be completely wrong.

What I am trying to do is raise your awareness for your hearing the same way. Unfortunately perception of sound is far more complicated than cold or hot. That is why people go so wrong drawing conclusions from what they perceive by their brain, regardless of what the ears captured.
 

Empirical Audio

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The Mutec track was a poor choice IMO because it's unfamiliar electronic music with too much bass. In any case I did an evaluation, gave it my best shot.

Using Off-Ramp 6 USB converter driving my Overdrive SX DAC and Amarra/iTunes for playback (in order of preference):

1) Plus_Ref10
- Most 3-dimensional of the tracks
- Deep sound stage
- HF detail almost as good as RME Clock SSL
- Bass was not fatigueing
- HF shaking noise in the background not as apparent, but pushed way back
- Not dry sounding

2) RME Clock SSL
- Very good HF detail
- Shallower soundstage than Ref10
- Bass was not fatigueing

3) Quantum
- Not as focused as Ref10
- Similar sound to Clockt, but more 3D
- Bass slightly fatigueing
- Less dry than Clockt
- Shallower soundstage than Ref10
- HF not as good as RME Clock SSL

4) Clockt_Alles
- Shallow sound stage
- Dry sounding
- Bass is fatigueing
- Shaking noise in the background very apparent

Steve N.
 

Empirical Audio

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If you touch a metal in your home, it will feel colder than fabric. You probably know that the temp of the metal is the same as the fabric. The meta feels colder because it draws away the heat from your hand. The conclusion then that the metal is colder than fabric would be completely wrong.

What I am trying to do is raise your awareness for your hearing the same way. Unfortunately perception of sound is far more complicated than cold or hot. That is why people go so wrong drawing conclusions from what they perceive by their brain, regardless of what the ears captured.
If you think that this is the first time I have had this conversation, you would be mistaken.
 

Krunok

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If you touch a metal in your home, it will feel colder than fabric. You probably know that the temp of the metal is the same as the fabric. The meta feels colder because it draws away the heat from your hand. The conclusion then that the metal is colder than fabric would be completely wrong.

What I am trying to do is raise your awareness for your hearing the same way. Unfortunately perception of sound is far more complicated than cold or hot. That is why people go so wrong drawing conclusions from what they perceive by their brain, regardless of what the ears captured.
He will not accept your reasoning no matter how well you present it as long as it doesn't fit his beliefs. And he will not accept your measurement as long as it doesn't fit his beliefs. Whatever you tell him and whatever data you present to him it will not change his mind as it is he who knows the best what he is hearing, right? And you simply can't beat that "argument".
 

Empirical Audio

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He will not accept your reasoning no matter how well you present it as long as it doesn't fit his beliefs. And he will not accept your measurement as long as it doesn't fit his beliefs. Whatever you tell him and whatever data you present to him it will not change his mind as it is he who knows the best what he is hearing, right? And you simply can't beat that "argument".
I can say the same about your beliefs.
 

Krunok

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I can say the same about your beliefs.
No, you can't, because I'm changing mine when I'm given a good reasoning and/or facts, like precise measurement. And as much as you are proud of not changing your beliefs I'm proud of changing mine when given enough reason or facts. That's the main difference between you and me.
 

amirm

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If you think that this is the first time I have had this conversation, you would be mistaken.
I suspect you have not had it with anyone who has had experience with sighted plus countless controlled tests of the same conditions. I am not parroting what I have read online. Getting listening right was part of my job, my teams and major company's revenue and reputation.
 

Empirical Audio

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FYI the gear has arrived. The note from Steve says to burn it in for 2 days before testing ???!???
Also, I forgot to mention that I recommend plugging the AC power for the LPS into the same circuit/outlet if possible as the AP or the DAC, whichever is fed by the SM. This is because this particular version of the SM has isolated input, but not isolated output. It's what I call "OTL" or output transformerless. This is to reduce ground-loop noise in the measurements.
 

amirm

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Also, I forgot to mention that I recommend plugging the AC power for the LPS into the same circuit/outlet if possible as the AP or the DAC, whichever is fed by the SM.
I do that for all of my testing.
 

jtwrace

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FYI the gear has arrived. The note from Steve says to burn it in for 2 days before testing ???!???
Another reason to put it on the bench now, test it. Then follow the directions and retest to actually see if there's a change. Personally, I'd like to see cold, 45 min warmup and his "48 hr golden burn in" :facepalm:
 

Empirical Audio

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I will post the offset test tracks here to see if anyone can hear differences in these and pick out the one that is most live and accurate sounding. These all have identical data sections, but different offsets or # of nulls before music starts.

The problem is that the uploader will not allow me to attach sample .wav track files here, so I need a method to make them available.
 

Sir Sanders Zingmore

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Ok, "trolling" was maybe not the best word I could have used but then maybe you as a native english speaker can suggest a better word for a person who is presenting his subjective impressions as facts in a very stubborn way and constantly avoiding to accept any rational arguments?
I think that he thinks he is being rational.
My test of rationality vs belief is whether someone is honestly prepared to change their opinion in the face of contrary evidence.

By the way I had no idea that you weren’t a native English speaker. I’m a native Australian speaker - not sure if that’s the same thing :)
 

FrantzM

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FYI the gear has arrived. The note from Steve says to burn it in for 2 days before testing ???!???
There you go!! You must use one of those audiophile burn in material on the DAC input...
And it must be powered through the Nordost I mentioned earlier..
When will this be deemed unacceptable? Pretty soon the gear may react badly because it wasn't properly burned-in???!!!
 
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Blumlein 88

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I will post the offset test tracks here to see if anyone can hear differences in these and pick out the one that is most live and accurate sounding. These all have identical data sections, but different offsets or # of nulls before music starts.

The problem is that the uploader will not allow me to attach sample .wav track files here, so I need a method to make them available.
Put them in a zip file and it will take it.
 

mansr

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The silliest part of all this is that deploying an ASRC in this manner is a bad idea in the first place. To see why, consider what happens to the signal.

In the best possible case, the PLL in this gadget is perfect, producing a completely jitter-free reference matching the average rate of the input. This is still going to differ slightly from the local oscillator. The S/PDIF spec allows a 50 ppm deviation in high accuracy mode, 1000 ppm with normal accuracy. The ASRC resamples the data to compensate for the discrepancy. This resampling is, however, imperfect. Firstly, all calculations have a limited precision, so there will be rounding errors. Secondly, the possible resampling ratios are not continuous. Even if the steps are small, they are steps nonetheless. If, as is likely, the required ratio falls between two available values, the actual ratio used will oscillate between the nearest values such that the correct long-term average is maintained. This is a form of jitter that is being irreversibly burned into the data.

More realistically, the PLL isn't quite so perfect and lets some (mostly low-frequency) jitter through. This will also be burned into the data by the ASRC, on top of the inevitable rounding errors described above.

Once the ASRC has done its thing, the result is re-encoded as S/PDIF and transmitted under control of the local oscillator. This oscillator may be good, better than average even, but it will have some jitter.

When, finally, the signal arrives at the target DAC, the timing recovery mechanism used there, whatever principle it uses, will add its own jitter signature along with any residual from the input it receives.

The upshot of all this is that no matter how good the DAC is at handling jitter, the reclocker will be restricting the achievable quality. There may possibly be some benefit if the DAC is unusually poor and the source is exceptionally jittery. In that case, the $700 are probably better spent on a more competent DAC or a less jittery source.
 
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