Jump to content
IGNORED

John Swenson tutoring paper: "Considerations regarding usage of external reference clocks" (EtherREGEN and other): Sine vs. square, impedance, cables—and a money saving surprise at the end.


Recommended Posts

Thank you for the pointed white paper. 99% clear.

 

Since I use a quality Ref10 clock, I'm left  wondering about my cables.

 

How much does attenuation plays a rule in a 1.5 cable? Professional companies gives  their specs @ 100m runs. 

For example, the attenuation of Canare LV-77S @ 100' is 1.0. Can things get any lower? LV-61S @ 100' is 1.3.

 

 

Secondly, if performance can be improved, can anyone recommend a low attenuation 75ohm cable?  By the meter or feet is better, as I solder my BNC cables myself.

Stereo

[Genelec 1032C x 2 + 7360 x 2] <== [MC3+USB x 3 <-- REF10 SE120] <== [AERIS G2] <== [EtherRegen x 2]
Chain switchable to [Genelec 8331 x 2 + 7350]


Surround

[Genelec 1032C x 3 + 8431 x 2  + 7360 x 2] <== [MiniDSP U-DIO8] <== [Mac Mini] 

Link to post
Share on other sites
18 minutes ago, JohnSwenson said:

Raw attenuation doesn't matter, it is how the attenuation changes with frequency that matters. So the numbers you quoted don't make any difference, what you need is the attenuation vs frequency graph. The flatter the graph below 1GHz the better. The problem is you cannot compare graphs from different companies since the scales are almost always different. Even within the same company the scales are frequently different.

 

The Canare LV-77S spec sheet has a table for this with several of their models. You can tell by looking at this table that the LV-77S has significantly less change with frequency than the others do. This is the information you need to look at to compare cables.

 

Note this is only if you are using square wave output, if you are using sine wave it doesn't matter.

 

John S.

 

Very helpful, John!

 

And yes, I can see how the increments on the LV-77S is lower than the other cables.

Guess I've just pointed me at the right direction...

Stereo

[Genelec 1032C x 2 + 7360 x 2] <== [MC3+USB x 3 <-- REF10 SE120] <== [AERIS G2] <== [EtherRegen x 2]
Chain switchable to [Genelec 8331 x 2 + 7350]


Surround

[Genelec 1032C x 3 + 8431 x 2  + 7360 x 2] <== [MiniDSP U-DIO8] <== [Mac Mini] 

Link to post
Share on other sites
46 minutes ago, LowMidHigh said:

 

Very helpful, John!

 

And yes, I can see how the increments on the LV-77S is lower than the other cables.

Guess I've just pointed me at the right direction...

 

Hi there,

 

Canare LV-77S does have the lowest attenuation with frequency of the listed cables here:

http://www.canare.com/ProductItemDisplay.aspx?productItemID=74

 

I have been using this up to now for a square wave cable.

 

Of course the info shared today changes things .. lol I might just be buying an AfterDark sine wave clock now!

 

Will read and re-read a few more times first though ....

 

For square wave cable hunters though, Belden 1694A does look to be even better (lower) by the metric of attenuation vs frequency:

 

https://catalog.belden.com/techdata/EN/1694A_techdata.pdf

 

Best,

James

Link to post
Share on other sites
2 hours ago, James Stephens said:

 

Hi there,

 

Canare LV-77S does have the lowest attenuation with frequency of the listed cables here:

http://www.canare.com/ProductItemDisplay.aspx?productItemID=74

 

I have been using this up to now for a square wave cable.

 

Of course the info shared today changes things .. lol I might just be buying an AfterDark sine wave clock now!

 

Will read and re-read a few more times first though ....

 

For square wave cable hunters though, Belden 1694A does look to be even better (lower) by the metric of attenuation vs frequency:

 

https://catalog.belden.com/techdata/EN/1694A_techdata.pdf

 

Best,

James

 

Excellent tip, James.

 

Regrettably, the Canare and the  Belden measurements don't fully overlap, but where the do, the 1694A does measure better. 

I have a small spool of Furutech FP-62 on hand, but the company doesn't publish any numbers, so I'm reluctant to use it.

I guess Belden it is.

Stereo

[Genelec 1032C x 2 + 7360 x 2] <== [MC3+USB x 3 <-- REF10 SE120] <== [AERIS G2] <== [EtherRegen x 2]
Chain switchable to [Genelec 8331 x 2 + 7350]


Surround

[Genelec 1032C x 3 + 8431 x 2  + 7360 x 2] <== [MiniDSP U-DIO8] <== [Mac Mini] 

Link to post
Share on other sites

Thanks so much for this great explanation 

 

sign me up for a filter 🙂

 

does it make sense to use 2 filters? One in each side, maybe 2 different types?

would that cover more of the bandwidth and capture any of the noise that may leak through the first filter?

 

or maybe just use the BBP-10.7, which is a band pass?

Link to post
Share on other sites

Dear John,

Does the filters as mentioned by you alzo improve  the performance of my Afterdark Giesemann Clock Sin Wave???

 

And I have same question as GMG at both ends specified filter?

Quote

Audio. :4x Bonn Silent Angel 8P, Afterdark Emperor Crown Masterclock and Cybershaft 75 Ohm,Mini Circuits convertor,Uptone EtherRegen with 75Ohm. SOTM Cat CAT 7, Auralic Vega G2.1, Cambridge Edge W, Kef Ref 3 speakers.  Power: Farad super 3 ( 2x) , Keces P8 ( 2 Uptone LPS1.2 ) Afterdark 5V: Cables:Meicord Opal, SOTM Cat7 with filtering, Ghent Audio DC , Farad Level 2, Sharkwire speaker

Link to post
Share on other sites

@Superdad

 

Hi! Alex,

 

Thanks for your edited white paper. I hope this information will help us to found their best 10M Master Clock for EtherREGEN.  We followed your white paper with all specifications. Not surprise our best seller now is Queen - square wave for EtherREGEN special edition. 

 

We did measure the clock with Phase Noise @1Hz / 10Hz with Allan Derivation plotted, with the Clock cable made from leading Suhner + Huber from Swiss, this cable is very high specification cable available in the market now. 

 

I believe most customer can enjoy the lowest phase noise to the circuit being clocked. 

 

Thanks again for make this white paper happened!!! 

 

Best Regards,

Adrian

AfterDark.

Amp: Goldmund 27+ EVO Preamp, Goldmund 29M Power Amp, Goldmund AC-Curator

DAC: Goldmund 21D Convertor Mono Block x 2 

Digital: Mutec MC3-USB,  AfterDark. Giesemann OCXO 10M Master Clock Giesemann EVA 

Playback: Goldmund PH3 Phono Amp, Linn LP12, Rovox PR99 MKII Open Reel

Digital Player: AfterDark. Rosanna Network Bridge x Roon Bridge OCXO Edition x JS-2

Dealer: SMSL, Gustard, Cybershaft, Pachanko Studio, UpTone Audio, Waversa, DELA

Link to post
Share on other sites
10 hours ago, Superdad said:

Many of our friends here at Audiophile Style have been waiting for us to publish John Swenson's introductory explanations concerning choosing and implementing an external reference clock—be it for connection to an EtherREGEN or some other audio device.

 

[I take the blame for the delay. John gave me the first draft of his paper just over two months ago. The concepts were pretty clear but I think he wrote it late at night so it needed a few editing/formatting passes. I finally had time this past week to prepare it for presentation.]

 

Here is a link to the PDF for offline reading: Considerations regarding 10MHz external reference clocks...

And below are the JPGs of the pages.

 

We do not expect that this paper will answer all questions about the complex realm of high-frequency reference clocking, but it is a start. Nor does this paper get deeply technical and there are some generalizations.

 

After reading it, feel free to ask questions.

 

As teased in the thread title, at the end of the paper we present a shortcut to getting stellar performance out of less than state-of-the-art clocks.

If there is interest, we may begin stocking the item mentioned--mostly for convenience of our overseas clients as the company selling the small, inexpensive item charges $120 for shipping to destinations outside the USA.

 

Enjoy!

--Alex C.

===================

 

624535702_UpTone-J.SwensonClockpaperpg.1.thumb.jpg.8ce5908dcfa699920a42d9287eb6402f.jpg

834775361_UpTone-J.SwensonClockpaperpg.2.thumb.jpg.7a77b065bc81f80b9c4d463a394feda4.jpg

1761935705_UpTone-J.SwensonClockpaperpg.3.thumb.jpg.2f827bd7ecdbb473859a20ecb73ecdab.jpg

455923025_UpTone-J.SwensonClockpaperpg.4.thumb.jpg.45eba0317b65fd0675bc8dc12ece4de0.jpg

 

 

Hi! Alex,

 

We are receiving the BLP-10.7 + adaptor on next Mondy, and looking forward to test with our Giesemann Clock in sine wave. Really excited if this can unlock the potential for our Giesemann Clock to work with EtherREGEN. 

 

Thanks again.

 

Best Regards,

Adrian

AfterDark. 

 

 1102061028_Screenshot2021-03-27at5_02_40PM.thumb.png.3f7455f19947ec195d8248175ca13e64.png

Amp: Goldmund 27+ EVO Preamp, Goldmund 29M Power Amp, Goldmund AC-Curator

DAC: Goldmund 21D Convertor Mono Block x 2 

Digital: Mutec MC3-USB,  AfterDark. Giesemann OCXO 10M Master Clock Giesemann EVA 

Playback: Goldmund PH3 Phono Amp, Linn LP12, Rovox PR99 MKII Open Reel

Digital Player: AfterDark. Rosanna Network Bridge x Roon Bridge OCXO Edition x JS-2

Dealer: SMSL, Gustard, Cybershaft, Pachanko Studio, UpTone Audio, Waversa, DELA

Link to post
Share on other sites
1 hour ago, MartinT said:

 

But the Canare LV-77S sounds better!  Trust your ears, it's not just about measurements.

 

I haven't used either, but I doubt I'll be able to hear any difference in a ref clock application. (Hell, I had to temporarily replaced a home-brewed Furutech cable with a $2 BNC/BNC and I couldn't detect anything different). 

 

Still, I believe a solid core is less prone to skin effect than a stranded core, which might explain why Belden measures better than the Canare. 

Stereo

[Genelec 1032C x 2 + 7360 x 2] <== [MC3+USB x 3 <-- REF10 SE120] <== [AERIS G2] <== [EtherRegen x 2]
Chain switchable to [Genelec 8331 x 2 + 7350]


Surround

[Genelec 1032C x 3 + 8431 x 2  + 7360 x 2] <== [MiniDSP U-DIO8] <== [Mac Mini] 

Link to post
Share on other sites
6 minutes ago, LowMidHigh said:

 

I haven't used either, but I doubt I'll be able to hear any difference in a ref clock application.

 

Within 30 seconds or................📣

Quote

Audio. :4x Bonn Silent Angel 8P, Afterdark Emperor Crown Masterclock and Cybershaft 75 Ohm,Mini Circuits convertor,Uptone EtherRegen with 75Ohm. SOTM Cat CAT 7, Auralic Vega G2.1, Cambridge Edge W, Kef Ref 3 speakers.  Power: Farad super 3 ( 2x) , Keces P8 ( 2 Uptone LPS1.2 ) Afterdark 5V: Cables:Meicord Opal, SOTM Cat7 with filtering, Ghent Audio DC , Farad Level 2, Sharkwire speaker

Link to post
Share on other sites

I heard quite clearly the upgrade in sound quality between LV-61S and LV-77S.

 

It's a surprise playing with different cables. The Belden 4694R sounds different again.

TP-Link MR6400 4G router > Uptone EtherREGEN reclocker > Sonore ultraRendu streamer > Mutec MC-3+ USB reclocker > LKS MH-DA004 DAC > Burson AB-160 XLR buffer > Belles SA-100 power amp > Usher Dancer Be-20 speakers. BG7TBL master clock. PS Audio P3 & P10 regenerators. Coherent, Mad Scientist, Wireworld & Canare cables.

https://theaudiostandard.net

Link to post
Share on other sites

Are there any other clocks, besides I imagine the Mutec Ref 10 and Ref 10 SE 120 (?), for which we might expect the square wave output into an ER to surpass its sine wave output (+ of course the Mini-Circuits filter)?

 

Thanks!

Link to post
Share on other sites

I have a question fo my own here to John. Given we have the figures for both the Bedlen 1694A and Canare LV-77S, which of the two would he recommend over the other? Going by the numbers alone, the Bedlen is superior, but some people here claim that the Canare "sound" better. Kind of a contradiction, so I hope he could weigh in. 

Stereo

[Genelec 1032C x 2 + 7360 x 2] <== [MC3+USB x 3 <-- REF10 SE120] <== [AERIS G2] <== [EtherRegen x 2]
Chain switchable to [Genelec 8331 x 2 + 7350]


Surround

[Genelec 1032C x 3 + 8431 x 2  + 7360 x 2] <== [MiniDSP U-DIO8] <== [Mac Mini] 

Link to post
Share on other sites
45 minutes ago, Superdad said:

 

[When you accidentally posted your question in AfterDark’s “Filter group buy” thread I answered there. But since you caught that the question is more appropriate here, I’ll just repost my long answer below...]

 

Hi James:

While I understand what you are asking, the phrasing of the latter part of your question does not really fit. You seem to imply that there are first-rate clocks that offer both square and sine waves from the same box. That’s not the case with the Mutec (square only) nor any of the better boxes from Asia (mostly sine) that I am aware of.

 

As John explained in his paper, it takes a lot of care to both produce a really good square wave AND to preserve that quality (via cabling) all the way to the target device. Not that it can’t be done.  And OXCO modules (the circuits in the cans along with the crystal) are available with square wave output. But how that is implemented and handled varies greatly.

Also, some companies (and I have no idea about what AfterDark does to offer square wave in some models) use sine>square circuits between the OCXO module and the output.  There exist a couple of chips that do this extremely well, but then there are the rest which are rather poor at it (and then the truly terrible squarer mess that is in the BG7TBL boxes).


So with inexpensive square wave output clocks you really never know what you will get. Yet with sine wave clocks you need to be very careful to filter to a very clean wave—best done at the endpoint target device end.

 

Back to your question—which likely was more meant to be something like:
“Can a really low-phase noise sine wave output clock—terminated with the Mini-Circuits filter—outperform a first-rate square wave box such as a Mutec REF10 SE20 (assuming $$$ also spent on a cable for that square wave)?

 

I certainly can’t answer that and I think John would decline to as well without making extremely careful (and rather difficult to set up) measurements.  And even the characteristics of the receiver in the endpoint target would likely have significant affect on such a comparison.

 

I write all the above primarily so that we can all begin thinking about these things from the proper angles. It’s confusing stuff! B|

 

Hi Alex,
 
Thanks very much.
 
There are of course sine + square wave output choices for BG7TBL and some AfterDark clocks but I forgot there wasn't a sine wave output for the Mutec clocks. 🤭
 
Ok here goes again lol:
 
My sense having read the clock paper is that square wave outputs are to be avoided except perhaps in the case of the Mutec clocks .. and that is what I was driving at in my question .... although I was trying to simultaneously enquire whether there might be any other clocks besides the Mutec that might have a good enough square wave output that it is worth consideration.
 
.. of course even then I get it that preserving that square wave all they way to the target device has its challenges.
 
Thanks again to you and John for everything!
 
Best,
James
 
Link to post
Share on other sites
19 minutes ago, LowMidHigh said:

I have a question fo my own here to John. Given we have the figures for both the Bedlen 1694A and Canare LV-77S, which of the two would he recommend over the other?

 

It's really the Belden 4694R that should be compared with the Canare LV-77S.  And they sound really close albeit slightly different in character.

 

1694A is a lesser cable and sounds inferior.

TP-Link MR6400 4G router > Uptone EtherREGEN reclocker > Sonore ultraRendu streamer > Mutec MC-3+ USB reclocker > LKS MH-DA004 DAC > Burson AB-160 XLR buffer > Belles SA-100 power amp > Usher Dancer Be-20 speakers. BG7TBL master clock. PS Audio P3 & P10 regenerators. Coherent, Mad Scientist, Wireworld & Canare cables.

https://theaudiostandard.net

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×
×
  • Create New...