Review and Measurements of Empirical Audio Synchro-Mesh

[amirm]

Please do it with a Khadas. I bet it does nothing.

My Khadas unfortunately has been loaned out so can't test that.

 

[bunkbail]

My Khadas unfortunately has been loaned out so can't test that.

Unlucky. I'm really curious how the Syncromesh would improve this graph .

 

[RayDunzl]

you need to recalibrate out to Alpha Centauri.

I already had, but hadn't yet seen the point of posting that which hadn't been mentioned...

-444dB to Andromeda, -522dB to the edge of the observable universe...

 

[gvl]

iFi SPDIF iPurifier is a fraction of the cost and said to be bit-perfect. If one is in the market for a re-clocker why pay more?

 

[amirm]

As requested, here are the results for two other DACs.

First, Schiit Modi 3 ($99):

Same results as Modi 2 Uber. It seems Schiit didn't fix anything in the S/PDIF interface.

Here is Topping DX7s ($500):

DX7s has far superior jitter rejection as compared to Schiit Modi 3. As a result, the Synchro-Mesh doesn't nothing here.

 

[gvl]

Kudos on the great review btw, probably the best practical jitter illustration I've seen on the internets.

If you have cycles to run a similar review for the iFi SPDIF iPurifier I can supply one. I know you've done one in the past but it would be interesting to see same tests done to it, in particular it'd be interesting to see if the bit-perfectness claim is true or in other words it is simply a FIFO buffer, i.e. noise floor remains unchanged.

 

[amirm]

I'd like to see what the S-M does to the digital data. The residual jitter from its PLL ought to be visible there.

Is this what you are asking about? This is digital end to end with jitter amount changed:

This is with 12 kHz tone so that it is easier to understand. But has dither so noise floor is higher than my review measurements.

 

[HammerSandwich]

I already had, but hadn't yet seen the point of posting that which hadn't been mentioned...

Huh. I just assumed you didn't see the point of shouting in a vacuum.

 

[Newk Yuler]

I am not sure Steve will be in a mood to send me more gear after this review. Maybe one of you can send in yours....

I didn't get that impression. It wasn't a bad review. It wasn't awesome, but the SM isn't suppose to be especially awesome. It's been around for a long time with a few revisions along the way and proved excellent longevity like most of Steve's products. The test proves it still performs to a decent, respectable degree by modern standards and its value is dependent on the hardware surrounding it. Finally the value of the Synchro Mesh (as it is now) is becoming questionable versus increasingly better performing and less expensive modern tech. It means Steve has to adjust again to stay on his game. Advancement driven by ambition and capital potential. Yay free enterprise! (He may be doing this as he reads this.)

The SM has been something to stick between a CD, DVD, or Bluray player used as CD transports, or streamers like the old Squeezebox, etc with not particularly well developed digital parts and a DAC that benefits from its effect, which has been a lot of stuff over the years. The SM has been a little more "general consumer" oriented, IMO based on casual observation. The Off Ramp should be viewed differently. Upscale.

If you don't hear from him when the Off Ramp 6 becomes available, well... I won't apologize for putting him on the spot.

 

[Blumlein 88]

Very nice approach to this review. Superb explanation about what you are doing.

I do think Schiit should release the Dingleberry DAC that has enough jitter to shake the music loose.

A year later they can release the Wyper reclocker to fix it.

 

[Zog]

Thank you very much, @amirm , for this review and most especially for the fantastic clarity with which you explained the concepts involved, your process, and how to interpret the results. Like the best professors, I always feel that you elevate those you are teaching or sharing your expertise with, with no arrogance or talking down to your audience! Much appreciated!

+1 Even I am in danger of understanding.

 

[RayDunzl]

Huh. I just assumed you didn't see the point of shouting in a vacuum.

I was more concerned with the 3.4 million years it would take the distant shout to reach the listener...

 

[Blumlein 88]

I was more concerned with the 3.4 million years it would take the distant shout to reach the listener...

Sound has negative gravity particles you know. Might speed it up some leaving here, but might slow it down some getting there. I guess round about 3 million years it doesn't matter. It will have one year jitter embedded in it anyway. But 31 billionths of a hertz jitter is what I would call pretty close in, so likely masked by the main tones.

 

[HammerSandwich]

They could see the shouting then, but the sound would take a bit longer.

 

[bennetng]

I'd like to see a digital capture of a J-test with added jitter. It would also be interesting to see the behaviour (frequency response and such) of the resampler with inputs at some other sample rates, both lower and higher than its native 96 kHz.

I have more of a problem that this resamples everything to 96 khz. Most music I listen to is at 44.1 khz. What impact does this have on timing and a bit perfect signal when it is resampled to 96 khz?

Don't know if it is what you proposed.
https://www.audiosciencereview.com/forum/index.php?threads/digital-distortion.2059/post-55543
The test signal used is not a J-Test signal, but the difference is still easily measurable.

This difference is measurable even in the analog output:
https://www.audiosciencereview.com/forum/index.php?attachments/spdif-zip.9914/

 

[Zog]

Sound has negative gravity particles you know. Might speed it up some leaving here, but might slow it down some getting there.

It also depends on what is being said. "May I lend you $1K" when spoken travels faster than "May I borrow $1K"

 

[soundwave76]

Great review as always! Also a tip of the hat to Steve for sending the device for testing. It was a brave move and one can only wish that more hifi manufacturers would do the same and/or test and measure their devices properly themselves.

 

[watchnerd]

Here is a hypothetical question/ scenario:

People rightly ask what the point is for an SPDIF reclocked in an age of asynchronous USB and Ethernet based streamers/DACs.

But what about active speakers with digital input, e.g. JBL 705P/708P, Dynaudio Core 7/59, etc?

And how does AES / EBU change the use case?

 

[soundwave76]

^ This interests me as well. I have digital active speakers (Genelec 8331+7350) and I have compared two USB-AES interfaces in the past few days - the Matrix XSPDIF and Mutec MC-3+ USB with reclocking. I heard no differences, which didn't surprise me.

 

[restorer-john]

Perhaps Steve may consider using an ASRC like the one I suggested in the synchro-mesh thread? Considering the per unit (chip) costs are the same and there is >30dB to be had, it may be a good idea.

There could be a case for his synchro-mesh unit, one where audiophiles own older, previously high performing, expensive 32-48KHz standalone 16-18 bit D/As from the RBCD transport/dac era. I can see there may be justification to consider such a device in that situation and I think that should be considered perhaps before a wholesale dismissal.

A poor design decision was made at the time to make the source the master and embed the sample timing within the data stream.

It should be mentioned and corrected in this context, that Sony, from their very first separate transport/ D/A converter, the CDP-1/DAS-R1, recognized the issue with the possible future use of external D/A converters and designed a synchronized (clock sent to DAC and slaved) connection to the D/A converter. It's certainly not a 'poor design decision'.

See picture below:

Twin PLLs used by other manufacturers, along with much improved transports, FIFO buffering and more robust CIRC implementations meant 'slaved' connections were deemed unnecessary.

What the originators could not foresee, was the endless, and in my opinion, futile obsession with ever increasing sample rates and bit depths.