Mutec REF 10 Masterclock

[simone]

3 hours ago, pam1975 said:

+1!

+2!

[svart-hvitt]

READING MATERIAL ON CLOCKS

 

I think many (including myself!) need reading up on clocks. So I thought I'd share this readworthy link, referenced by TapeOp:

 

http://pinknoisemag.com/pink-papers/pink-paper-002

 

Maybe Julian could tell us how the Ref10 compares with the other clocks mentioned in the article, i.e. both specifications wise and "philosophically" (i.e. the design idea behind the product).

 

It would also be nice if other readers would comment on the findings and impressions of the Pink Noise people in order to further our understanding of the Mutec Ref10.

[modmix]

From some tests since 2014 using various 10 MHz source, I too came to the conclusion that Jrms close to the carrier is one of the best figures to determine sonic quality of such a device used as reference to a MC-3+.

 

From Cybershaft rubidium clock...low priced option?:

On 28.9.2016 at 8:18 PM, Elberoth said:

Here is the revised clock graph from the first page. I have also added the Sforzato PMC-01 BVA clock, which is the only clock in the world based on the Oscilloquartz BVA-8607 OCO module:

 

 

The numbers used in this table, are based on minimum manufacturer guaranteed values. The actual samples may exceed those numbers.

 

REF 10 gives just 7 fs (10-100Hz) - using phase noise figures given above in this thread and http://www.abracon.com/phaseNoiseCalculator.php.

 

One has also take into account the signal form (eg. sinusoidal, squared) for one simple reason: the receiver has to detect at which point in time the signal did pass the threshold region. A faster transition gives less jitter added by the input stage. From my experience, a factor of 3 is a good number to compare these types of signals.

 

The devices listed above give sinusoidal signals, too my best knowledge.

REF 10 has a square wave output signal, => < 2 fs (10-100Hz), if my experience applies here, too.

 

hth

Ulli

 

 

[jelt2359]

So I connected the rednet's word clock output to the mutec word clock input just to try and see if it will work. With this connected, the extern + reclock mode is now available. I still don't see any "word clock out" lights come up, strangely.

 

But on my rednet, "internal" clock reference plays perfectly fine, whereas the "external" breaks up from time to time (Im using a coaxial cable with a bnc adaptor so maybe impedance issues are a problem?). Not sure what's going on, and if there's even any clock signal coming from the mutec given that no "clock out" lights are on. 

 

Julian could you confirm how to make this work? The goal of course is to see if I should get a ref10 and connect it to my mutec, with the ideal use case of the mutec being a clock distributor and reclocker, both. 

[Elberoth]

9 hours ago, modmix said:

From some tests since 2014 using various 10 MHz source, I too came to the conclusion that Jrms close to the carrier is one of the best figures to determine sonic quality of such a device used as reference to a MC-3+.

 

From Cybershaft rubidium clock...low priced option?:

 

REF 10 gives just 7 fs (10-100Hz) - using phase noise figures given above in this thread and http://www.abracon.com/phaseNoiseCalculator.php.

 

One has also take into account the signal form (eg. sinusoidal, squared) for one simple reason: the receiver has to detect at which point in time the signal did pass the threshold region. A faster transition gives less jitter added by the input stage. From my experience, a factor of 3 is a good number to compare these types of signals.

 

The devices listed above give sinusoidal signals, too my best knowledge.

REF 10 has a square wave output signal, => < 2 fs (10-100Hz), if my experience applies here, too.

 

hth

Ulli

 

 

 

The figure to look at, is the phase noise below 1Hz. Below that number BVA-8607 OCXO still rules supreme. 

 

But the BVA-8607 is:

- extremely expensive ($10k+);

- no longer available (there is a new version made by Rakon, but it is even more than the original BVA-8607 ...).

 

If the numbers given for this new OCXO are accurate, then the price/performance ratio is off the charts good.

[julian.david]

6 hours ago, jelt2359 said:

So I connected the rednet's word clock output to the mutec word clock input just to try and see if it will work. With this connected, the extern + reclock mode is now available. I still don't see any "word clock out" lights come up, strangely.

 

But on my rednet, "internal" clock reference plays perfectly fine, whereas the "external" breaks up from time to time (Im using a coaxial cable with a bnc adaptor so maybe impedance issues are a problem?). Not sure what's going on, and if there's even any clock signal coming from the mutec given that no "clock out" lights are on. 

 

Julian could you confirm how to make this work? The goal of course is to see if I should get a ref10 and connect it to my mutec, with the ideal use case of the mutec being a clock distributor and reclocker, both. 

 

Ok, this is getting a bit off topic and would be better placed in the MC-3+ thread. Ultimately I'm not 100% sure what you're trying to achieve, but in general it's not really a good idea to try to re-clock a source and simultaneously externally clock the same source with the MC-3+/MC-3+USB. I sort of get the idea behind this endeavor, but it doesn't make a whole lot of sense and (potentially) gets you into trouble.

 

Some basic thoughts about using the MC-3+/MC-3+USB in this scenario:

1. Unless you have a very high grade (superior) clock source like the REF 10, you're best off sticking to "internal" and "reclock" mode.
2. Externally locking the source (rednet) to the MC-3+/MC-3+USB via the latter's Word Clock outputs creates somewhat of a "chicken & egg" problem. The re-clocker is looking for the incoming digital audio stream and will adjust its sample rate accordingly. Once it's locked, it will start outputting a Word Clock signal with the same sample rate (and phase-coherent). At the same time, the source (rednet) is looking for a Word Clock signal to lock to and is expecting the re-clocker to provide such. That's a bit of stalemate and not really what you want.
3. It becomes questionable why exactly you'd want your source (rednet) to lock to an external Word Clock anyway, since it would dictate the sample rate of your system. But what if you want to playback music with different sample rates? Switch it manually all the time?

Maybe we can move this discussion over to the other thread or continue via PM/email so this thread can focus on the REF 10?

[jelt2359]

Thanks for the reply. 

 

My ultimate goal is to do this with the Ref10, hence my questions here...

 

I'm only doing this now with the Rednet's clock as an experiment, because I do not have any other external clock. I was hoping to buy the Ref10 for this purpose. 

 

I will move my question over to the 3+ USB thread, no problem. 

[julian.david]

6 minutes ago, jelt2359 said:

Thanks for the reply. 

 

My ultimate goal is to do this with the Ref10, hence my questions here...

 

I'm only doing this now with the Rednet's clock as an experiment, because I do not have any other external clock. I was hoping to buy the Ref10 for this purpose. 

 

I will move my question over to the 3+ USB thread, no problem. 

 

Got it, no problem. When you add the REF 10, you could now run the MC-3+/MC-3+ in "external" and "re-clock". But what I explained above in points #2 and #3 still applies!

 

Since the Rednet doesn't have a 10 MHz input, you'd need some other clock (like an MC-3+) in addition to the re-clocker (as a separate unit) to convert the 10 MHz signal into a Word Clock signal. But again, then you would have to manually change the clock in the Word Clock generator every time you want to play back music with a differing sample rate. Is that really what you want?

[jelt2359]

Thanks Julian. That's exactly what I'm looking for! So am I right to say that; as long as I manually adjust the clock rate (you'll be surprised what lengths some of us audiophiles go to, heh.) then putting it in EXTERN + RE-CLOCK mode will exactly achieve what I am looking to do?

 

I believe that's already exactly what those who are using external clocks with their Rednet and Mutec 3+ USB are doing today...

 

PS, I have also written on the other thread. Please feel free to reply there instead if it's more suitable there.

[Confused]

I posted a question yesterday that I think was not totally clear in my own post, and then got a little lost due to subsequent posts on other topics.  Anyway, I would be interested in some clarity on the subject, so I will try again.

 

My understanding is that AES protocol includes a clock signal.  So if you have a REF 10 providing the reference to a Mutec MC3+USB, which then feeds a DAC via AES input, you are then (presumably) feeding the DAC with a very accurately clocked feed thanks to the REF 10 and MC3.  Will the DAC's internal clock benefit from this feed and effectively use the super accurate clock in this feed?  Or does the DAC's internal clock (presumably less accurate) basically take precedence in the end, hence nullifying the benefit of the REF 10 & Mutec MC3? 

[svart-hvitt]

^

+1

[modmix]

1 hour ago, Confused said:

My understanding is that AES protocol includes a clock signal.

Yes - implicitly.

Data are encoded prior to transmission in a so-called Biphase Mark Code format (more e.g. at http://scanlime.org/2011/04/spdif-digital-audio-on-a-microcontroller/).

 

A DAC has to extract the embeded clock => SPDIF decoder's job.

from: http://peufeu.free.fr/audio/extremist_dac/spdif.html

 

1 hour ago, Confused said:

Will the DAC's internal clock benefit from this feed and effectively use the super accurate clock in this feed?

In case the DAC just uses the recovered clock, of course having a more precise clock will help (given there is a good SPDIF decoder involved).

 

1 hour ago, Confused said:

Or does the DAC's internal clock (presumably less accurate) basically take precedence in the end, hence nullifying the benefit of the REF 10 & Mutec MC3?

There are concepts like this where clock delivered over the cable is used solely to corse adjust an internal clock (note that the source clock will never be exact 44.1kHz or so; the receiver must adajust to the real sample rate in order to avoid droped or missing samples).

from: http://www.latentlaboratories.com/blog/2015/2/2/dsp-01-part-7-totally-working-spdif-audio

In such a case adding a REF 10 might have less effect.

 

hth

Ulli

[modmix]

7 hours ago, Elberoth said:

The figure to look at, is the phase noise below 1Hz.

This is stated from time to time by various people, yes.

No rational seen so far, though...

 

From my unterstanding, phase noise below 1 Hz (e.g. 0.1 Hz) means time error takes place at a rate of e.g. 10 sec - correct?

 

When comparing various 10 MHz clocks the sonic impact could be easily heard at the attack of a single tone played on a piano - definitely not lasting 10 sec. ,-)

 

I'm of the impression that having a low noise figure below 1 Hz normally coincide with low figures at frequencies above 1 Hz - bad idea?

[svart-hvitt]

21 hours ago, modmix said:

From some tests since 2014 using various 10 MHz source, I too came to the conclusion that Jrms close to the carrier is one of the best figures to determine sonic quality of such a device used as reference to a MC-3+.

 

From Cybershaft rubidium clock...low priced option?:

 

REF 10 gives just 7 fs (10-100Hz) - using phase noise figures given above in this thread and http://www.abracon.com/phaseNoiseCalculator.php.

 

One has also take into account the signal form (eg. sinusoidal, squared) for one simple reason: the receiver has to detect at which point in time the signal did pass the threshold region. A faster transition gives less jitter added by the input stage. From my experience, a factor of 3 is a good number to compare these types of signals.

 

The devices listed above give sinusoidal signals, too my best knowledge.

REF 10 has a square wave output signal, => < 2 fs (10-100Hz), if my experience applies here, too.

 

hth

Ulli

 

 

Seems like the MSB 33 Femto (i.e. 33 femtoseconds for the entire frequency range) is a bit ahead of the Ref10, does it?

 

http://www.audio-focus.com/MSB/msb_femto_33_clock.html

[modmix]

41 minutes ago, svart-hvitt said:

Seems like the MSB 33 Femto (i.e. 33 femtoseconds for the entire frequency range) is a bit ahead of the Ref10, does it?

Reminds me of playing Autoquartett when I was a child - more speed, more power and the hack.

But - let's play it ,-)

And, I guess, we do talk about electrical properties and leave money out of the game...

Luckily we can simply compare what the respective manufacture gives on their respective page:

  REF 10    femto 33       freq.range
  28.8fs           31.8fs             1-100
    7.3fs            7.8fs            10-100 

  51.4fs          42.3fs       1-100,000
  43.2fs          28.9fs     10-100,000
unknown         1ps      0.1-100,000

 

Looks like we do have two winners - depending on the frequency range

From some years of soundwise comparing OCXOs I do have an idea which frequency range is of more importance when it comes to sq.

BTW: is there a stand alone Femto 33 (including case, psu, clock distribution and the like)?
If so, what kind of output signal does it deliver?

[svart-hvitt]

25 minutes ago, modmix said:

Reminds me of playing Autoquartett when I was a child - more speed, more power and the hack.

But - let's play it ,-)

And, I guess, we do talk about electrical properties and leave money out of the game...

Luckily we can simply compare what the respective manufacture gives on their respective page:

  REF 10    femto 33       freq.range
  28.8fs           31.8fs             1-100
    7.3fs            7.8fs            10-100 

  51.4fs          42.3fs       1-100,000
  43.2fs          28.9fs     10-100,000
unknown         1ps      0.1-100,000

 

Looks like we do have two winners - depending on the frequency range

From some years of soundwise comparing OCXOs I do have an idea which frequency range is of more importance when it comes to sq.

BTW: is there a stand alone Femto 33 (including case, psu, clock distribution and the like)?
If so, what kind of output signal does it deliver?

To my knowledge this femto 33 unit is to be embedded onto the MSB Dac-circuitry.

 

It's on another level, however, price wise compared to Ref10. As is all MSB gear (some of the most expensive you can get).

 

It would be nice to hear from Julian, given the phrase "industry leading" in the marketing material for the Ref10.

[CKKeung]

9 hours ago, svart-hvitt said:

To my knowledge this femto 33 unit is to be embedded onto the MSB Dac-circuitry.

It's on another level, however, price wise compared to Ref10. As is all MSB gear (some of the most expensive you can get).

It would be nice to hear from Julian, given the phrase "industry leading" in the marketing material for the Ref10.

 

MSB Femto33 clock module is more expensive than Ref10.

Its real advantage is that it's on the circuit board and so close to the other crucial onboard sections.

[julian.david]

14 hours ago, svart-hvitt said:

To my knowledge this femto 33 unit is to be embedded onto the MSB Dac-circuitry.

 

It's on another level, however, price wise compared to Ref10. As is all MSB gear (some of the most expensive you can get).

 

It would be nice to hear from Julian, given the phrase "industry leading" in the marketing material for the Ref10.

 

The Femto 33 is €15,000 and (more to the point) it's essentially a clock option to be built into a DAC. The phase noise performance we quote for the REF 10 is not measured at some arbitrary internal probe point, but actually at the finished product's clock outputs. So you're not really comparing apples to apples here. One of the central design considerations for the REF 10 was to transfer the OCXO performance to the usable outputs with minimal losses. 

[svart-hvitt]

Thanks for replying, Julian.

 

I think good designers should just take the bull by the horn and explain their design choices. Transparency is a big plus for competent designers.

 

One ssue remains, however: What happens to the OCXO performance when it's transferred from output via cable? What is the integrity of the signal when you introduce a cable (length, quality of cable) into the equation?

[julian.david]

5 minutes ago, svart-hvitt said:

Thanks for replying, Julian.

 

I think good designers should just take the bull by the horn and explain their design choices. Transparency is a big plus for competent designers.

 

One ssue remains, however: What happens to the OCXO performance when it's transferred from output via cable? What is the integrity of the signal when you introduce a cable (length, quality of cable) into the equation?

 

Yes, those are important points! But since we can't control those parameters, it's impossible to make generalized statements about them other than what I have said before: use a high quality cable and keep it as short as possible! 

 

Apart from that my hope is that we will have some data to illustrate the effects of cable length some time in the future. Not to make absolute claims, but at least to give you an idea of "what happens when". 

[austinpop]

On 6/13/2017 at 3:19 AM, julian.david said:

 

 

We are working on a compatibility list for DACs. There are definitely a few out there already such as the Esoteric D-1, D-02X and D-05X, TEAC NT-503, Antelope Zodiac, and we are expecting there to be more manufacturers jumping on the bandwagon in the future.

 

Thanks so much, Julian. 

 

Timely too, as there was just a Massdrop sale on the Teac!

 

May I quickly test my understanding with you on a particular scenario? Assuming USB as the connection mechanism with a DAC that utilized asynchronous USB. Also let's assume the transport chain is:

• SOtM sMS-200ultra (with master ref clock in) > SOtM tX-USBultra (with master ref clock in) > a DAC with master ref clock input
• All 3 are driven by the Ref 10, from 3 of the 8 outputs of the Ref 10

My understanding of this scenario - for USB:

1. The master for the data communication is the DAC
2. The master for the clock reference is the Ref 10

And my expectations of SQ improvements over the baseline with no Ref 10:

1. Even without a DAC with a reference clock input, the scenario with the Ref 10 supplying the 2 SOtM Ultra components, there should be a sonic benefit.
2. The benefit would be even greater if the DAC too accepted the reference clock.

Would you agree?

 

[seeteeyou]

Granted it's still about arbitrary numbers, could we still draw any (meaningful?) conclusions based on their measurement of DuCULoN from NDK?

 

http://www.ndk.com/en/ad/2013/001/index.html

http://www.ndk.com/tc/news/2015/1190895_e.pdf

http://www.ndk.com/en/ad/2013/001/pdf/c_NH47M47LA_e.pdf

 

[BigAlMc]

I've read this full thread twice now and am an interesting mix of confused, intrigued and better educated!  Good thread guys. 

 

Am particularly intrigued following the glowing feedback that @romazposted. 

 

I see Julian has said they'll publish a list of compatible DACs & Streamers but meantime I hope a couple specific questions are ok. 

 

I have a Microrendu to Singxer SU-1 combo providing my PS Audio directstream dac with a terrific signal over I2S.  

 

My first question is whether the SU-1 is likely to be compatible with the Ref 10 clock output and whether the benefits would be maintained in the I2S output? (I've put some work into getting the SU-1 sounding great so would be reluctant to reconsider it at this stage). 

 

My second question is if the SU-1 isn't compatible itself would it benefit from having the Mutec MC3 + in between the Microrendu and the SU-1? And if so then would adding the Ref 10 further improve the USB signal going into the SU-1? 

 

Though at 4 grand that's a hell of a decrappifier to consider! 

 

Finally if I assume that the SU-1 isn't compatible then I guess it's a case of waiting for the SOtM SMS-200 ultra vs UltraRendu shootout and then deciding if there's a sufficient argument for changing the NAA upstream of my SU-1 in order to be better placed to incorporate some masterclock goodness. 

 

Many Thanks, 

Alan 

[BigAlMc]

No answer for 2 days - doh! - does that mean I asked a doozy of a dumb question??

[romaz]

6 hours ago, BigAlMc said:

No answer for 2 days - doh! - does that mean I asked a doozy of a dumb question??

 

Not a dumb question.

 

Your SU-1 has no master clock input option nor does its clock operate at 10MHz and so there is no direct way to associate the REF10 with the SU-1 although there is an indirect way.

 

This is where SOtM's revolutionary new sCLK-EX board comes in but there's a catch.  This new clock board has the option of a 10MHz master clock input (50 or 75ohm) and further has 4 independent (but synchronized) outputs that can be used to replace the clock of almost any component (i.e. router, switch, motherboard, LAN card, video card, USB card, etc).  I know this as I have done it already and the results have been spectacularly good, so good that I have purchased a 2nd sCLK-EX board and will be replacing 4 more clocks in my chain (a total of 8 clocks) from the router all the way to my final endpoint.  What this means is that I will have every clock in my audio path replaced and the REF10 will be used to synchronize all 8 clocks.  Moreover, since the REF10 will be powered by its well thought out linear PSU and since each of SOtM's clock boards (and its 4 clocks) can be powered by a high quality linear PSU (in my case, my Paul Hynes SR7), regardless of the dirty environment that each clock is placed into (ie a music server), each clock will be powered very cleanly.  What kind of improvement this leads to, I'm not yet sure, but thus far, the results with 4 clocks replaced have been breathtakingly good.  

 

In theory, the sCLK-EX can be used to replace the clock on the SU-1 and I'm willing to bet, based on my own experience so far and based on the comments made by others, that there will be an improvement even without the REF10 but the improvement will be even larger with the REF10.  The only problem is SOtM has suggested they will not replace clocks on products made by other audio companies.  Whether there are exceptions to the rule, I'm not sure.

 

If you are interested in my further impressions of the REF10, they are posted here: