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Many people are intrigued by the recently introduced superclock in the SOtM Ultra series.  Now Auralic says they will have a superclock in their G2 product line along with the G2 Aries, Vega and processor.

 

So what's a superclock?  Chances are that SOtM and Auralic don't mean precisely the same thing.  This is going to get interesting.  It's the new buzzword.

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1 minute ago, jabbr said:

 

Precision clocks come with a phase noise plot that specifies phase error vs offset frequency. Without this specification you are buying marketing jargon FWIW

OK, thanks!  I trust you will bring some good perspective to this thread as we learn more about SOtM Ultra and Auralic G2.  Since the term superclock is starting to show up everywhere, we need to be better educated consumers if we care to understand what we're buying. 

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32 minutes ago, rickca said:

OK, thanks!  I trust you will bring some good perspective to this thread as we learn more about SOtM Ultra and Auralic G2.  Since the term superclock is starting to show up everywhere, we need to be better educated consumers if we care to understand what we're buying. 

Here's a spec sheet on a widely available part that goes for $14: http://www.crystek.com/crystal/spec-sheets/clock/CCHD-575.pdf

 

You'd want the close-in phase error (e.g. @1Hz) to be substantially better than this -- note that this is "femtosecond" range, so be very very careful before spending $$$ on marketing fluff.

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28 minutes ago, jabbr said:

Here's a spec sheet on a widely available part that goes for $14: http://www.crystek.com/crystal/spec-sheets/clock/CCHD-575.pdf

 

You'd want the close-in phase error (e.g. @1Hz) to be substantially better than this -- note that this is "femtosecond" range, so be very very careful before spending $$$ on marketing fluff.

Some other points: about the measurements shown on clock datasheets:

- is this a random clock from a batch that was measured or is it the'best' one found during manufacturing? In other words what's the quality range of these clocks - 10%, 20%, 50% tolerance?

- What PS was used for the measurement - was it a standard PS found in most audio devices or some high quality laboratory supply?

- What other conditions applied when taking these measurements - ensuring constant temperature, faraday cage, etc?  

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40 minutes ago, mmerrill99 said:

Some other points: about the measurements shown on clock datasheets:

- is this a random clock from a batch that was measured or is it the'best' one found during manufacturing? In other words what's the quality range of these clocks - 10%, 20%, 50% tolerance?

- What PS was used for the measurement - was it a standard PS found in most audio devices or some high quality laboratory supply?

- What other conditions applied when taking these measurements - ensuring constant temperature, faraday cage, etc?  

 

Reasonable points and questions: Yes, the oscillator manufacturers are measuring their clocks--and the performance of those is of course not at all the same as the jitter performance of a complete DAC.

 

I will tell one interesting story:

Crystek has gotten a LOT better making their XOs!  18 months ago John and I requested and received samples of their CCHD-575 (the one Jonathan linked to above).  Got 25.0MHz version (for testing in the ISO REGEN).  They sent us 3 samples, and they each came with individual phase-noise plots.

Whereas the data sheet on Crytek's web page shows -100dB for 10Hz offset (in the mid-20MHz f-range we are using), the plots for the 3 samples we got were -108dB, -110dB, and -112dB at 10Hz!   

Of course our first thought was that they hand-selected these and that production runs could not be anywhere near as good as these.  So I immediately picked up the phone and called Crystek (they are actually not that large a company; one sales engineer seems to handle the whole country).  They said no, the samples were not at all specially selected--just measured right off the line. And he said that their processes have improved so much that the $9.60 CCHD-575 (that's what I paid for the first 500 pieces; goes to $9.30 ea. @ 1,000) now outperforms their big $27 CCHD-957 as used in a lot of top-tier DACs.   I told him they ought to update the 575's datasheet on the web to reflect that.  Guess he did not relay that suggestion to their marketing department. :/

 

Of course if you want to see eye-popping phase-noise performance, then check out the Pulsar Clock. -118dB to -123dB at 10Hz!  But it is 420 Euros...

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6 minutes ago, Superdad said:

 

Reasonable points and questions: Yes, the oscillator manufacturers are measuring their clocks--and the performance of those is of course not at all the same as the jitter performance of a complete DAC.

 

I will tell one interesting story:

Crystek has gotten a LOT better making their XOs!  18 months ago John and I requested and received samples of their CCHD-575 (the one Jonathan linked to above).  Got 25.0MHz version (for testing in the ISO REGEN).  They sent us 3 samples, and they each came with individual phase-noise plots.

Whereas the data sheet on Crytek's web page shows -100dB for 10Hz offset (in the mid-20MHz f-range we are using), the plots for the 3 samples we got were -108dB, -110dB, and -112dB at 10Hz!   

Of course our first thought was that they hand-selected these and that production runs could not be anywhere near as good as these.  So I immediately picked up the phone and called Crystek (they are actually not that large a company; one sales engineer seems to handle the whole country).  They said no, the samples were not at all specially selected--just measured right off the line. And he said that their processes have improved so much that the $9.60 CCHD-575 (that's what I paid for the first 500 pieces; goes to $9.30 ea. @ 1,000) now outperforms their big $27 CCHD-957 as used in a lot of top-tier DACs.   I told him they ought to update the 575's datasheet on the web to reflect that.  Guess he did not relay that suggestion to their marketing department. :/

 

Of course if you want to see eye-popping phase-noise performance, then check out the Pulsar Clock. -118dB to -123dB at 10Hz!  But it is 420 Euros...

That's a good start - I didn't know they sent out phase noise plots with their clocks.

 

Did you get 500 plots then or is it just samples that plots come with?

 

Maybe they didn't update their datasheet because ......... - call me a cynic, hell call me anything you like :)

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1 hour ago, JohnSwenson said:

The term "superclock" means whatever the company using that term wants it to mean. There is no "official" definition of such a term. It is not even related to any specific measurement. The other term which has gotten a lot of press recently is "femtoclock", at least that is related to a measurement of jitter, but still doesn't give a threshold for what it means. It's like the term "fast car", at least you know it is referring to how fast it goes, but no clue where the threshold is between what is considered "fast" and what is "not fast".

 

As jabbr mentioned what does seem to have good correlation with sound quality is close in phase noise, so the phase noise plot is the most important piece of information when looking at clock specs. There are many other clock parameters, and some companies get caught up in optimizing those parameters which do not have correlation with good sound. Thus you can have the situation of a company saying their clock is a "superclock" when that is referring to an optimized parameter which has nothing to do with good sound.

 

A very favorite one is temperature coefficient. A really good oscillator might have something like 1ppm (parts per million) which sounds really good, it is something the marketing department can really highlight, but unfortunately has nothing to do with the phase noise, which is what really matters. As a matter of fact the circuitry which radically decreases the temperature coefficient in a TCXO (Temperature Compensated Crystal Oscillator) actually significantly increases the phase noise. So if you see someone using a TCXO in a DAC, you know they don't really know how to choose the right oscillator. 

 

There is another class of oscillator called the OCXO which you might have heard of (Oven Compensated Crystal Oscillator) which heats a special crystal to a high temperature which produces an extremely low temperature coefficient, say 1PPB, yep 1 part per BILLION. But again that does not guarantee very low phase noise. It does turn out that the lowest phase noise oscillators are OCXOs, but not all OCXOs are really low phase noise. There are a lot of inexpensive OCXOs that are much worse than the Crystek 575. To get an OCXO that has lower phase noise than the 575 takes a lot of money.

 

John S.

 

 

 

+1

 

Is like the term "SUPER FOODS", they sell a lot using this 'label'  :)

 

Roch

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1 hour ago, JohnSwenson said:

The term "superclock" means whatever the company using that term wants it to mean.

 

 

Thank you, John.  That's exactly why I started this thread.

 

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31 minutes ago, elcorso said:

Is like the term "SUPER FOODS", they sell a lot using this 'label'  :)

 

Yes, hemp seeds are particularly magical.  They make listening practically a religious experience.

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6 hours ago, Superdad said:

 

Of course if you want to see eye-popping phase-noise performance, then check out the Pulsar Clock. -118dB to -123dB at 10Hz!  But it is 420 Euros...

 

Then there is building your your own ala the @andrea_mori thread on DIY. Having a good crystal is particularly important as is a clean power supply. Crystals from Laptech in Canada. One point to remember is that the specs get worse as the oscillator frequency goes up (physics) so best to use the lowest frequency you need. This suggests that for DSD, perhaps DSD1024 won't be better than DSD512 but the exact point when things get worse is as yet unknown. For USB and Ethernet it is entirely unclear that doing any better than a Crystek will give any better performance. Measurements to demonstrate this are sorely lacking.

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1 hour ago, jabbr said:

 

Then there is building your your own ala the @andrea_mori thread on DIY. Having a good crystal is particularly important as is a clean power supply. Crystals from Laptech in Canada. One point to remember is that the specs get worse as the oscillator frequency goes up (physics) so best to use the lowest frequency you need. This suggests that for DSD, perhaps DSD1024 won't be better than DSD512 but the exact point when things get worse is as yet unknown. For USB and Ethernet it is entirely unclear that doing any better than a Crystek will give any better performance. Measurements to demonstrate this are sorely lacking.

 

You are of course correct on all counts there.  Though John and I followed Andrea Mori'sclock thread for a while--they certainly when to a lot of interesting lengths--it seems that in the end the exercise resulted in clock boards which still just had comparable phase-noise, nothing eye-popping that I can recall, though it has been a while since I checked in on that project.

 

As for USB and Ethernet clocks, yeah, we don't see any need to go crazy on those.  But early on in the ISO REGEN dev cycle we had boards populated identically except that one set had just the CCHD-3391 as used on all original USB REGENs since the beginning, and the other set had the CCHD-575.  In auditioning the two, it took all of 15 seconds for us to decide that $8.40 per board ($1.20 versus $9.60) was WAY more than worth it.  VERY AUDIBLE!  Though I admit that for a USB clock it almost does not make sense that it would be so audible. :o

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Would be interesting to get some measurements from SoTM and their newer SClock Ex board, which they are implementing into their Ultra lineup of components.  Roy (Romaz) has found them to make a significant difference in his system, Ethernet and USB.  Guess we will find out soon as far as mobo also. 

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5 hours ago, JohnSwenson said:

The term "superclock" means whatever the company using that term wants it to mean. There is no "official" definition of such a term. It is not even related to any specific measurement.

 

I'm agree. We are need check numbers anyway.

 

But clock stability is not matter as itself in audio applications.

It impact to noise and distortion level at output of DAC.

Need to compare spectrums (and time-spectrum diagram) for test audio sine signals on several frequencies passed thru device(s), clocked by different sources.

 

Also again we get matter of "threshould of audibility".

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DuCULoN should be one of the best

 

http://www.head-fi.org/t/745032/lks-audio-mh-da003/285#post_12775721

 

Someone in Japan compared DuCULoN and Pulsar, DuCULoN just wiped the floor

 

http://asoyaji.blogspot.com/2015/06/duculon.html

 

It's so hardcore if you ask me

 

http://musicbird.jp/audio_column/p103/

http://musicbird.jp/audio_column/p145/

http://musicbird.jp/programs/koreda-audio2/201511/

http://musicbird.jp/programs/koreda-audio2/201704/

 

0Ckjnjy.jpg

 

Here they are

 

http://www.ndk.com/en/ad/2013/001/index.html
http://www.ndk.com/en/news/2015/1190895_e.pdf
http://www.ndk.com/en/ad/2013/001/pdf/c_NH47M47LA_e.pdf

 

Quote

In case of export from Japan, export licenses are required in advance.

 

http://www.diyaudio.com/forums/digital-source/306544-ripping-wav-sd-card-4.html#post5050947

http://www.diyaudio.com/forums/digital-line-level/192465-asynchronous-i2s-fifo-project-ultimate-weapon-fight-jitter-360.html#post4372663

 

Quote

They say the product is under a law enforcement to inhibit a possible military use in some notorious countries.

 

Prohibit or inhibit? Whatever that meant. LOL

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Everything is ITAR regulated. Rolls Royce made us do export control test.. oh god the pain. MILITARY just pick what they like. North Korean audiophiles probably  can't use Schitt multi bit Dacs with old Missile timing chips in them.

Strange they give South Korea Shit all the time..?

Thanks for the education though gent's.

Spec and implementation, not fancy titles..?

 

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6 hours ago, ElviaCaprice said:

 

Deleted

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I guess the price of NDK DuCULoN makes SoTM sCLK-EX modules look reasonably priced in comparison.  I wonder what oscillator SoTM is using.  At what point do better clocks become overkill?

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Great thread with valuable input by many.  Like with power supplies, these "super" clocks come with lots of claims and promises but few actual measurements leaving the consumer to make their own comparisons.  Not always easy or practical to do. 

 

I don't claim to be a clock expert and so all I can do is trust my ears and report what I hear.  Like many here, I have owned or tried various reclocking devices from a USB Regen, W4S Recovery, PS Audio Lan Rover, iFi Micro iUSB 3.0 and a large number of USB-to-SPDIF converters.  Some have made a small difference while others have resulted in larger differences.  What impact is due to the clock vs other factors is not always easy to discern.  With SOtM's "standard" and "Ultra" line, the clock is the only difference and so the exercise has been educational.  Can a clock by itself make a large difference with respect to SQ?  In my experience, absolutely and emphatically, YES.  

 

With SOtM's new clock, I have no idea of just how good it is relative to other clocks.  SOtM has promised to provide measurements but thus far have not delivered.  Regardless, the delta I am hearing between their standard model and their Ultra model is significant.  The fact that they can provide 4 independent clocks with customizable frequencies on a single board that can be powered by a single 1A PSU is what makes this new clock so special for the DIYer.  It opens up a new vista of possibilities.

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