Mutec REF 10 Masterclock

[pam1975]

yes @austinpop saw your previous comment on that. Just to be clear, ie SOtM's tests, was the 1m cable the better one?

[austinpop]

1 minute ago, pam1975 said:

yes @austinpop saw your previous comment on that. Just to be clear, ie SOtM's tests, was the 1m cable the better one?

 

No. Opposite.

 

The SQ dropped going from 0.3m to 1m.

[pam1975]

thanks for clarifying !

[Confused]

2 hours ago, austinpop said:

 

No. Opposite.

 

The SQ dropped going from 0.3m to 1m.

0.15m should sound lush then.?  Although equipment layout would start to get tricky.

[Confused]

3 hours ago, pam1975 said:

I will go for ref 10 on a SMS 200 ultra and my current Mutec MC3+ USB. 

i have the ref 10 on pre-order already, waiting for news from Mutec.

I will share impressions here although I won't be able to measure anything  

Keep us updated!  It looks like a few of us are interested in this one.

[svart-hvitt]

LENGTH OF WORD CLOCK CABLES

 

Antelope Audio says that the BNC cable connection stability begins to degrade after the 250th meter.

 

But maybe golden ears experience degradation after 30 centimeters? Does austinpop have any further evidence that 30 centimeters are a crucial limit for word clock cables?

[austinpop]

30 minutes ago, svart-hvitt said:

LENGTH OF WORD CLOCK CABLES

 

Antelope Audio says that the BNC cable connection stability begins to degrade after the 250th meter.

 

But maybe golden ears experience degradation after 30 centimeters? Does austinpop have any further evidence that 30 centimeters are a crucial limit for word clock cables?

 

Nope.  I'm not making claims.

 

Just asking the question. Does master clock cable length matter? And referring to what SOtM have reported.

 

I'd rather just hear what Mutec - @julian.david et al. - have to say. 

 

No need for snideness.

 

 

[svart-hvitt]

1 hour ago, austinpop said:

 

Nope.  I'm not making claims.

 

Just asking the question. Does master clock cable length matter? And referring to what SOtM have reported.

 

I'd rather just hear what Mutec - @julian.david et al. - have to say. 

 

No need for snideness.

 

 

 

I think extraordinary claims need extraordinary evidence. Your and SOTM's claim of 30 centimeters is as extraordinary as Antelope's 250 meters claim.

 

However, we know that Antelope is a big clock producer, delivering word clock gear to Hollywood productions and the like. Sotm is more of a boutique isn't it?

 

I too look forward to seeing what Mutec says. If they side with the Sotm claim or the Antelope policy of pretty long cable runs.

[jelt2359]

Cable lengths aside, I'd like to ask about the mutec 3+ USB and ref10 combination being used as a word clock to my Rednet 3. Will this be beneficial? Or should I just use the mutec pair as a reclocker after the Rednet 3 without using it as a word clock reference as well?

[pam1975]

7 hours ago, svart-hvitt said:

Your and SOTM's claim of 30 centimeters is as extraordinary as Antelope's 250 meters claim.

@austinpop did not *claim* anything. He's asking a question.

 

You on the other hand talk about Antilope's claim that connection stability degrades after 250m. 

He is talking about SQ as a function of cable length, not connection stability.

[svart-hvitt]

5 hours ago, pam1975 said:

@austinpop did not *claim* anything. He's asking a question.

 

You on the other hand talk about Antilope's claim that connection stability degrades after 250m. 

He is talking about SQ as a function of cable length, not connection stability.

Pam, austinpop said, quote:

 

"The SQ dropped going from 0.3m to 1m".

 

Sounds like a claim to me. He used no qualifiers.

 

My intention was bringing some cold water into the discussion, separating audiophilia from audiophoolia, so to speak.

 

Don't you see there's a discrepancy between Antelope's suggestion of maximum 250 meters and austinpop's remark of 0.3 meters?

 

Antelope word clocks are used in Hollywood productions like the last Star Wars movie. Do you think Antelope will have their gear quality impaired due to cable length? Who has the most competence in said matter; the billion dollar movie industry or a Chinese hifi boutique?

 

However, I often find that there is no such thing as one universal truth. So a middle way is sometimes a good compromise. The compromise between Antelope's 250 meters and Sotm/austinpop's 0.3 meters is still about 100 meters.

 

Still, extreme clocks are delicate so maybe there is some truth to the claim that quality will be impaired somewhere between 0.3 meters and 250 meters. So I look forward to reading Mutec's take on this question.

 

[pam1975]

Good to hear Hollywood tested cable length on world clocks. In this case, absolutely, said boutique shop cannot compete.............

 

i agree with you - let's see if Mutec has an expert opinion on this.

but then again, Mutec is a boutique shop, so what shall we do then?

[svart-hvitt]

pam1975, there's an old (2010) discussion on clock cable length on Gearslutz:

 

https://www.gearslutz.com/board/music-computers/479654-clock-cable-length.html

 

The GS debate didn't conclude on a given, ideal length. However, nobody suggested that length should be below 1 meter.

 

Given the fact that word clocks have multiple outputs, imagine how the setup would look like if cable length were not to exceed 0.3 meters with, say 8, peripherals connected. Impossible to route 8 cables in that fashion, I think.

 

But I will await Mutec's answer because they're the ones who should know about signal strength etc. of their own clock.

[4est]

56 minutes ago, svart-hvitt said:

pam1975, there's an old (2010) discussion on clock cable length on Gearslutz:

 

https://www.gearslutz.com/board/music-computers/479654-clock-cable-length.html

 

The GS debate didn't conclude on a given, ideal length. However, nobody suggested that length should be below 1 meter.

 

Given the fact that word clocks have multiple outputs, imagine how the setup would look like if cable length were not to exceed 0.3 meters with, say 8, peripherals connected. Impossible to route 8 cables in that fashion, I think.

 

But I will await Mutec's answer because they're the ones who should know about signal strength etc. of their own clock.

 

There seems to be some confusion about how these are to be used. As noted, a word clock by intent has to be able to run longer cables. They are intended to sync all of the digital devices in a studio. They become the "master" and the rest are "slaved" to it. It is not a master (mclk) clock in the i2s sense. It is confusing.

 

This has nothing to do with the sms200ultra clocking, which is USB buss.

 

This  Mutek product is used to sure up the clocking on both the sotm USB and word clocks by providing super clean 10MHz signal that gets synthesized into the appropriate ones for that device. This requires that the ultra has other circuitry that the sms200 does not. One could always just add an internal upgraded clock mod to the sms200 at that correct frequency which is I think, 12MHz.

 

The efficacy of any of this is up to others.

[austinpop]

I appear to have ruffled some feathers, which was not my intent. 

 

I would really love to understand the difference between master clocks (10MHz), word clocks, and what started this for me - SOtM's interesting clock mod, which I'll describe below. This is what the relevant part of my chain looks like:

 

 

The sCLK-EX board in the tX-USBultra is generating clocks for all the devices. As part of the mods, the default clocks in the switch and the sMS-200 are replaced by clock signals sent from the sCLK-EX board. Without the tX-USBultra, and hence the sCLK-EX board powered on and active, the switch and sMS won't even function. These clock signals are at the required frequencies for the specific devices. If I remember correctly, its 24 and 25MHz.  

 

Now - you may look at this and ask - why on earth would you do this? Well - go read the thread!  It sounds better - amazingly better.

 

As far as I can tell, this clock distribution is neither a master clock, nor a word clock in the conventional sense. Is that right? It is in the context of this topology shown that the comments about cable length were made. SOtM have done experiments showing the SQ is better at sub-1m lengths. But this may just be for this special case.

 

What has intrigued many of us over on the other thread where this is being discussed is this: SOtM have started equipping the Ultra components - in my picture, the tX-USBultra - with a master clock connector, that accepts 10MHz @ 50ohm input.

 

This is where our two worlds intersect. This is why the interest here in the Ref 10. Given the Ultra chain as shown improves SQ so much, does the introduction of a master clock like the Ref 10 essentially goose the whole chain up to an even higher level of SQ? Gosh - that would be amazing! For many of us, the $3500 price tag is rather daunting, but this is the reason for all this interest.

 

So now - in the context of all of the above  - perhaps you understand the genesis of the question about cable lengths. I would love to hear the answer - master clock distribution is very robust to cable length, and lengths up to X meters are fine.

 

That's all I'm asking.

 

P.S. I just looked at the MC-3+ manual, since the Ref 10 manual isn't available yet. Here's the link: https://www.mutec-net.com/downloads/manuals/MUTEC_MC-3plus_Manual_E_screen.pdf. To quote:

 

Word Clock If a cable with a different impedance than 75Ω is used, a dramatic deterioration of the signal quality is the result! In this case, the sound quality and synchronization of all devices involved can be impaired. It is imperative that the lengths of all cables connected are largely the same to ensure that all devices will be synchronized in phase (exception: cable tolerances). We recommend using high-grade cables with a good shielding. A length of max. 10 meters (approx. 30 feets) should not be exceeded!

 

Assuming the same advice holds true for a 10MHz master clock, then we can just consider my question asked and answered. Awaiting Mutec's response.

[4est]

41 minutes ago, austinpop said:

I appear to have ruffled some feathers, which was not my intent. 

 

I would really love to understand the difference between master clocks (10MHz), word clocks, and what started this for me - SOtM's interesting clock mod, which I'll describe below. This is what the relevant part of my chain looks like:

 

 

The sCLK-EX board in the tX-USBultra is generating clocks for all the devices. As part of the mods, the default clocks in the switch and the sMS-200 are replaced by clock signals sent from the sCLK-EX board. Without the tX-USBultra, and hence the sCLK-EX board powered on and active, the switch and sMS won't even function. These clock signals are at the required frequencies for the specific devices. If I remember correctly, its 24 and 25MHz.  

 

Now - you may look at this and ask - why on earth would you do this? Well - go read the thread!  It sounds better - amazingly better.

 

As far as I can tell, this clock distribution is neither a master clock, nor a word clock in the conventional sense. Is that right? It is in the context of this topology shown that the comments about cable length were made. SOtM have done experiments showing the SQ is better at sub-1m lengths. But this may just be for this special case.

 

What has intrigued many of us over on the other thread where this is being discussed is this: SOtM have started equipping the Ultra components - in my picture, the tX-USBultra - with a master clock connector, that accepts 10MHz @ 50ohm input.

 

This is where our two worlds intersect. This is why the interest here in the Ref 10. Given the Ultra chain as shown improves SQ so much, does the introduction of a master clock like the Ref 10 essentially goose the whole chain up to an even higher level of SQ? Gosh - that would be amazing! For many of us, the $3500 price tag is rather daunting, but this is the reason for all this interest.

 

So now - in the context of all of the above  - perhaps you understand the genesis of the question about cable lengths. I would love to hear the answer - master clock distribution is very robust to cable length, and lengths up to X meters are fine.

 

That's all I'm asking.

 

P.S. I just looked at the MC-3+ manual, since the Ref 10 manual isn't available yet. Here's the link: https://www.mutec-net.com/downloads/manuals/MUTEC_MC-3plus_Manual_E_screen.pdf. To quote:

 

Word Clock If a cable with a different impedance than 75Ω is used, a dramatic deterioration of the signal quality is the result! In this case, the sound quality and synchronization of all devices involved can be impaired. It is imperative that the lengths of all cables connected are largely the same to ensure that all devices will be synchronized in phase (exception: cable tolerances). We recommend using high-grade cables with a good shielding. A length of max. 10 meters (approx. 30 feets) should not be exceeded!

 

Assuming the same advice holds true for a 10MHz master clock, then we can just consider my question asked and answered. Awaiting Mutec's response.

I am not sure who you are referring to, but this 10MHz product is not a master clock in any way, shape or form. It gets used with a word clock. The word clock acts as a "master" to slaves(ADCs,DACs ect). This is not masterclock/mclk. That term should be removed from the title in this thread as it will/has confused people. I do realize that SOtM use that term as well, but I do not think it is the appropriate term.

 

The sCLK board is available with different options for different uses.

 

Word clock is of a much lower frequency than the 10MHz Ref10 clock being discussed here. 10MHz is RF, and should be kept as short as practical.

 

 

[austinpop]

1 hour ago, 4est said:

I am not sure who you are referring to, but this 10MHz product is not a master clock in any way, shape or form. It gets used with a word clock. The word clock acts as a "master" to slaves(ADCs,DACs ect). This is not masterclock/mclk. That term should be removed from the title in this thread as it will/has confused people. I do realize that SOtM use that term as well, but I do not think it is the appropriate term.

 

The sCLK board is available with different options for different uses.

 

Word clock is of a much lower frequency than the 10MHz Ref10 clock being discussed here. 10MHz is RF, and should be kept as short as practical.

 

 

 

And now I am confused again. 

 

Here is the info sheet on the Ref 10: https://www.mutec-net.com/downloads/Ref10_InfoSheet_2014_E.pdf . The first sentence reads:

 

The MUTEC REF10 is a reference master clock generating 10MHz clock signals of ultra-low phase noise, to significantly improve the acoustical quality of digital audio devices.

 

I would love a link to a good primer that explains these terms. So is the right way to think of as follows:

1. There is a concept of master and slave. A device that accepts a master input becomes a slave, and uses that master to synchronize.
2. There is an orthogonal concept of word and reference clocks. Word clocks provide the clocks for audio data at the relevant data frequencies, whereas a reference clock is a single frequency (usually 10MHz) and is used purely for synchronization?

So you can have master word clocks, and master reference clocks?

 

Am I on the right path?

[rickca]

1 hour ago, 4est said:

this 10MHz product is not a master clock in any way, shape or form

OK now I'm confused.  What 10MHz product are you talking about?  Mutec calls the REF10 a reference master clock.

The SOtM sCLK-EX  can optionally have a master clock input connector at either 75 ohms or 50 ohms. 

[pam1975]

I understood exactly the same as you @austinpop, that is until @4est came crashing our little party

the ref 10 is definitely called by Mutec a "master reference" clock in their email correspondence with me...

 

[julian.david]

5 hours ago, svart-hvitt said:

pam1975, there's an old (2010) discussion on clock cable length on Gearslutz:

 

https://www.gearslutz.com/board/music-computers/479654-clock-cable-length.html

 

The GS debate didn't conclude on a given, ideal length. However, nobody suggested that length should be below 1 meter.

 

Given the fact that word clocks have multiple outputs, imagine how the setup would look like if cable length were not to exceed 0.3 meters with, say 8, peripherals connected. Impossible to route 8 cables in that fashion, I think.

 

But I will await Mutec's answer because they're the ones who should know about signal strength etc. of their own clock.

 

5 hours ago, pam1975 said:

Good to hear Hollywood tested cable length on world clocks. In this case, absolutely, said boutique shop cannot compete.............

 

i agree with you - let's see if Mutec has an expert opinion on this.

but then again, Mutec is a boutique shop, so what shall we do then?

 

22 hours ago, austinpop said:

 

Nope.  I'm not making claims.

 

Just asking the question. Does master clock cable length matter? And referring to what SOtM have reported.

 

I'd rather just hear what Mutec - @julian.david et al. - have to say. 

 

No need for snideness.

 

 

 

Hi all,

 

Sorry I've been absent from this discussion for a few days, but I'm glad to see so much interest in the REF 10. I'll do a bit of catching up in the next couple of posts. 

 

Let's start with cable length:

It's extremely difficult to give a clear-cut answer to this question since cable length is not the only parameter here. The type of cable, connectors, as well as the impedances on both ends (sender & receiver) also matter. But let's focus on two aspects:

1. The 10 MHz signal of the REF 10 (or any other 10 MHz clock) is not the same as a "ordinary" word clock signal. The whole purpose of the REF 10 is to provide an ultra low phase noise, super precise clock signal that can be used to enhance existing clocks and DACs. Thus, you can't just apply the same rules that have been valid for word clock signals. 
2. While you can theoretically run a word clock signal up to 250 meters that doesn't mean that you should do so if you can avoid it. Antelope can claim what they deem appropriate, but you bet that there will be significant losses when you run a 250 m stretch and expect precise clocking. Sure, you'll still get some signal out of it and it may still be acceptable for broadcast, but we would never recommend a cable run like that for audiophile purposes.
3. It's not a fail/don't fail, binary type of situation here. So it's not like we can give you a specific length at which point it just "won't work anymore". But you will start to see negative effects of the cable building up as the length increases. Imagine a "rounding off" of the super sharp square wave that the REF 10 puts out which makes the lock point less precise. 

So while we have recommended a maximum cable length of 10 meters for the word clock (!) signals in the MC-3+ manual, we definitely recommend keeping the cables for the REF 10 as short as you possibly can. What exactly does 

mean? Well, again it depends, and we're still working on an official statement, but I'd try to keep the length to no more than 1-3 meters. Shorter is better. We were using 0.5 meter cables at High End recently and that worked remarkably well. 

 

I'm hoping we can show you guys some data to illustrate the effects of cable length, but our focus is shipping product at the moment, which I'm sure some of you will appreciate. 

 

Onwards...

 

[julian.david]

15 minutes ago, pam1975 said:

I understood exactly the same as you @austinpop, that is until @4est came crashing our little party

the ref 10 is definitely called by Mutec a "master reference" clock in their email correspondence with me...

 

 

1 hour ago, austinpop said:

 

And now I am confused again. 

 

Here is the info sheet on the Ref 10: https://www.mutec-net.com/downloads/Ref10_InfoSheet_2014_E.pdf . The first sentence reads:

 

The MUTEC REF10 is a reference master clock generating 10MHz clock signals of ultra-low phase noise, to significantly improve the acoustical quality of digital audio devices.

 

I would love a link to a good primer that explains these terms. So is the right way to think of as follows:

1. There is a concept of master and slave. A device that accepts a master input becomes a slave, and uses that master to synchronize.
2. There is an orthogonal concept of word and reference clocks. Word clocks provide the clocks for audio data at the relevant data frequencies, whereas a reference clock is a single frequency (usually 10MHz) and is used purely for synchronization?

So you can have master word clocks, and master reference clocks?

 

Am I on the right path?

 

2 hours ago, 4est said:

I am not sure who you are referring to, but this 10MHz product is not a master clock in any way, shape or form. It gets used with a word clock. The word clock acts as a "master" to slaves(ADCs,DACs ect). This is not masterclock/mclk. That term should be removed from the title in this thread as it will/has confused people. I do realize that SOtM use that term as well, but I do not think it is the appropriate term.

 

The sCLK board is available with different options for different uses.

 

Word clock is of a much lower frequency than the 10MHz Ref10 clock being discussed here. 10MHz is RF, and should be kept as short as practical.

 

 

 

Maybe somebody is going to write a Wikipedia article about this or we'll put together some kind of primer. But yes, we are calling the REF 10 a reference master clock generator. It strictly generates 10 MHz signals that are unrelated to audio Word Clock signals (which would typically have the same sample rate as the audio stream). 

 

So @austinpop is correct in saying that there are master (word) clocks and master reference clocks. The MC-3+ and MC-3+USB are audio master clock generators for example (albeit with a 10 MHz input) that can be used to create and distribute Word Clock signals as well as Re-Clocking. The REF 10 is a pure reference clock generator that can be used to provide an ultra precise reference for master clock generators (like the MC-3+/MC-3+USB) and compatible DACs. 

 

What's interesting about all of this is that the concept of a master and slave is becoming a little bit confusing with 10 MHz clocks and Re-Clocking. It used to be that you would always have one master in a digital audio system that would set the sample rate, and a bunch of slaves, typically all connected via Word Clock. When dealing with the 10 MHz reference, I believe it's important to keep the reference clock mentally separate from the audio clock, because those are independent. 

 

Let's look at a simple example chain: 

Network player (S/P-DIF output) -> MC-3+ / MC-3+USB for Re-Clocking -> DAC

 

In this case, the network player is essentially the master of this system and it will output digital audio streams at various sample rates. The Re-Clocking picks up that sample rate, re-clocks the stream based on the internal clock, and outputs the audio to the DAC. If the sample rate of the source (the network player) changes, the sample rate of the entire system changes accordingly. No sample rate conversion takes place!!

 

Now if you add a REF 10 to this system, the only thing that changes is that the Re-Clocking within the MC-3+/MC-3+USB is now based on this ultra precise external clock signal of the REF 10 to increase the quality of the re-clocking process affecting the sound quality of the entire system. But everything else stays the same and the REF 10 is technically not the "master" of the system in the traditional sense of dictating the sample rate. 

 

Does that make sense to you all?

 

Julian

[julian.david]

1 hour ago, austinpop said:

 

Here is the info sheet on the Ref 10: https://www.mutec-net.com/downloads/Ref10_InfoSheet_2014_E.pdf . The first sentence reads:

 

 

Somewhat unrelated, but still important: this info sheet is ancient and will be replaced soon. Please refer to this post for the new version in the meantime: Posted Monday at 11:55 PM

 

Thanks,

Julian

[pam1975]

7 minutes ago, julian.david said:

Now if you add a REF 10 to this system, the only thing that changes is that the Re-Clocking within the MC-3+/MC-3+USB is now based on this ultra precise external clock signal of the REF 10 to increase the quality of the re-clocking process affecting the sound quality of the entire system. But everything else stays the same and the REF 10 is technically not the "master" of the system in the traditional sense of dictating the sample rate. 

makes sense, thanks @julian.david 

But *what if* the Ref 10 is now also connected to the network player?

how does this change the master/slave concept (if at all)?

 

[austinpop]

1 hour ago, julian.david said:

Well, again it depends, and we're still working on an official statement, but I'd try to keep the length to no more than 1-3 meters. Shorter is better. We were using 0.5 meter cables at High End recently and that worked remarkably well. 

 

Hi Julian,

 

That is exactly the clarity we were seeking! Thanks so much.

[austinpop]

1 hour ago, julian.david said:

 

Now if you add a REF 10 to this system, the only thing that changes is that the Re-Clocking within the MC-3+/MC-3+USB is now based on this ultra precise external clock signal of the REF 10 to increase the quality of the re-clocking process affecting the sound quality of the entire system. But everything else stays the same and the REF 10 is technically not the "master" of the system in the traditional sense of dictating the sample rate. 

 

Does that make sense to you all?

 

It does indeed, and clarifies the fact that there are distinct master-slave relationships in the digital audio chain, in terms of:

• the end-to-end word data clock between source and destination
• the word data clock for reclockers
• the reference clock for all or a subset of elements in the chain

and possibly others.