Jump to content
IGNORED

Reference & Word Clock Cables


Recommended Posts

It has been mentioned by others that clock cables are becoming of increasing interest, but posts on the subject are being spread through a number of different threads, notably the Mutec REF10 thread, SOtM threads and the infamous "A novel way...." thread.

 

So this is an attempt to to try to bring existing and future clock cable knowledge together, and with a bit of luck we should be able to identify some top performing clock cables that do not cost $1000's.

 

To start this thread off, I would like to pick up on the issue raised by @zoltan on the "A novel way...." thread.

 

Two things. 

For one, if you are in the EU, anything from outside the EU will cost 30-40% on top of the list price. In this case SOtM cables will be close to $1000 (I am almost sure that they will be sold around 800 euros) which makes them equally expensive as Habst. Shunyata is much more, needless to say.

 

Second, I bought a tx-USB ultra the other day as the last piece of the puzzle. I opened it to change the voltage to 12V. I noticed that the clock cable that goes from the input connector (inside of the BNC) to the board is curled up. I measured it and it is 40cm. By looking at it, it looks like more industrial than something in the league of high-end clock cables. I wonder how much our effort (both keeping short lengths and high quality) matters in this case when the last 40cm is something like that. 

Then again, given that SOtM is as good as it is (both products and as a company), my only conclusion is that they don't think that this matters that much. But why do they sell the first 1m for $700? As you can see, I am a little confused here.

IMG_0764.JPG

 

OK, I have to say that I was a little disappointed when I saw this post.  I have just purchased both a sMS-200Ultra and tX-USBultra and have spent some time and money buying custom made clock cables to optimise (minimise) clock cable length.  I then find that I probably have half a metre of cheap clock cable curled up in the case of the SOtM kit.  The addition of a reference clock connection is £200 when bought from the UK distributor for SOtM, or £400 in my case for the two units.  So this is not a cheap addition.  I guess my main frustration is that it seams to me that it would not take much additional effort to minimise the cable length from the connector to the board, oh well...

 

So this leads to a number of questions.

 

Firstly, does it really matter?  If so, what is the best way to resolve.  Could the units be sent back to SOtM for a more optimal solution?  Could users modify themselves, or would this invalidate warranty?

 

What would be the optimum solution anyway?  Simply shorten the cable?  Or maybe terminate the existing cable with a male connector, and use the cable to the board direct to the reference clock.  It occurs to me that you could simply disconnect the female from the case, pull the cable to the outside of the case, and connect direct to the reference clock with a female to female adaptor.  Is no (additional) cable better than a Habst cable?

 

I did demob my tX-USBultra from the system and took a look through the case vents.  Mine has the 75ohm connector, and it looks like the clock cable is a little different for the 75 ohm, it is copper coloured, but still appears to be over length.  I must admit that I was not prepared to open the unit, it is brand new with full warranty, so if I inadvertently broke something, it would be bad.  Some have mentioned that SOtM are fairly relaxed about users opening the kit, to adjust jumpers etc., but is this official policy, what about people shortening or replacing clock cables or whatever.

 

Maybe @MayfromSOtM would be kind enough to provide some good advice here?

Windows 11 PC, Roon, HQPlayer, Focus Fidelity convolutions, iFi Zen Stream, Paul Hynes SR4, Mutec REF10, Mutec MC3+USB, Devialet 1000Pro, KEF Blade.  Plus Pro-Ject Signature 12 TT for playing my 'legacy' vinyl collection. Desktop system; RME ADI-2 DAC fs, Meze Empyrean headphones.

Link to comment

If there were (much) better RF cables with TRUE 50Ω impedance that could be a good fit for those tiny little U.FL connectors, @romaz and others should have already ordered them a long time ago.

 

In other words, the (true) impedance must be right while the diameter should be less than 2.0 mm. We just don't have anything like that unless we cut some 50Ω clock cables up and then (try to) terminate them with U.FL connectors.

 

I just found those comments about cheap cables pretty funny since the only choices out there are the ones available from Digi-Key etc.

Link to comment
9 minutes ago, seeteeyou said:

If there were (much) better RF cables with TRUE 50Ω impedance that could be a good fit for those tiny little U.FL connectors, @romaz and others should have already ordered them a long time ago.

 

In other words, the (true) impedance must be right while the diameter should be less than 2.0 mm. We just don't have anything like that unless we cut some 50Ω clock cables up and then (try to) terminate them with U.FL connectors.

 

I just found those comments about cheap cables pretty funny since the only choices out there are the ones available from Digi-Key etc.

Interesting comment.  I presume the same is true in principle for SOtM kit with the 75 ohm clock feed?

Windows 11 PC, Roon, HQPlayer, Focus Fidelity convolutions, iFi Zen Stream, Paul Hynes SR4, Mutec REF10, Mutec MC3+USB, Devialet 1000Pro, KEF Blade.  Plus Pro-Ject Signature 12 TT for playing my 'legacy' vinyl collection. Desktop system; RME ADI-2 DAC fs, Meze Empyrean headphones.

Link to comment

@ConfusedThanks for starting the thread. It's been long overdue.

 

To comment on my own findings, I did ask the same thing from @MayfromSOtM who, as always, kindly and promptly answered. 
I will quote her reply here so she would not have to repeat it:

 

" The cable inside of the product case is effective much less noise external than the cable used in externally, so even though the cable inside of the product case is thin, there won’t be big loss. Of course, if the thick cable would be used internally, the result would be better but the thick cables are not available inside of our product.

 

And 40cm internal cable is our standard cable that used for all our product, and we don’t have the other length cable for the product."

 

That is pretty much we have all found on the internet as @seeteeyou also pointed out. 

 

I have not idea if a 20cm cable instead of a 40cm cable inside would really make an audible difference. Probably not large enough to justify the risk of damaging something inside as @Confused said. 

 

I hope somebody with a Habst or SOtM or Shunyata Research clock cable can tell us one day how big the difference is with the external part of the clock cable.

HQplayer - NAA - Devialet D-800 - YG Acoustics Carmel + dual ELAC sub-2090

Link to comment
1 minute ago, seeteeyou said:

We're only talking about those 50Ω U.FL cables between sCLK-EX and other SOtM components. Clock inputs from SOtM components are 50Ω. Clock outputs from sCLK-EX are also 50Ω. Obviously U.FL cables are 50Ω as well. Why would we mention anything about 75Ω?

SOtM products can be ordered with either. My SMS-200 ultra has 75 ohm input and my tx-USB ultra has 50 ohm input.

 

HQplayer - NAA - Devialet D-800 - YG Acoustics Carmel + dual ELAC sub-2090

Link to comment

I managed to catch Roy before he headed off for another extended trip, where he will be out of pocket. He confirmed that in his post about the "much longer clock cables," he was also referring to the internal reference clock cable. Here is the post:

https://www.computeraudiophile.com/forums/topic/30376-a-novel-way-to-massively-improve-the-sq-of-computer-audio-streaming/?do=findComment&comment=722848

 

To quote him (emphasis mine):

This is why I had to send my gear back to SOtM.  Because they didn't have the really short clock cables in stock, they ended up using much longer clock cables in my build which I ultimately deemed as unacceptable. 

 

He did say that were he to do it over, he would just source a shorter cable and DIY, since the U.FL connectors are snap on, snap off, and easy to swap.

 

Well, even though it doesn't involve soldering, I feel a lot of trepidation trying this. So for this exercise, I would ask the more handy, adventurous of you to try the shorter cable, and please report any perceived SQ improvement here.

 

<sits back and sips his beverage 9_9>

 

Link to comment
39 minutes ago, austinpop said:

 

 

Well, even though it doesn't involve soldering, I feel a lot of trepidation trying this. So for this exercise, I would ask the more handy, adventurous of you to try the shorter cable, and please report any perceived SQ improvement here.

 

<sits back and sips his beverage 9_9>

 

As I said, you could open the case, unscrew the female clock connector, gently liberate the clock cable from the glue blobs, pull the cable and female connector away from the unit.  My experimentation with very thick RG216 cables indicated that a 12" / 30cm cable is just long enough to run from the tXUSBultra to the REF10 if they are side by side.  So assuming the internal clock cable is 40cm, this should be enough to reach the REF10 (or other reference clock) and connect with just a female to female connector.  No soldering, no clipping, and no need for a Euro 800 Habst, and just about the shortest cable possible. 

 

I do wonder if this would invalidate warranty?  Maybe a question for @MayfromSOtM

 

Meanwhile....   Enjoy your drink^_^

Windows 11 PC, Roon, HQPlayer, Focus Fidelity convolutions, iFi Zen Stream, Paul Hynes SR4, Mutec REF10, Mutec MC3+USB, Devialet 1000Pro, KEF Blade.  Plus Pro-Ject Signature 12 TT for playing my 'legacy' vinyl collection. Desktop system; RME ADI-2 DAC fs, Meze Empyrean headphones.

Link to comment

Hi @Confused,

 

Great job starting this thread. 

 

It would be great if some of the the CAers with more expertise in this area could share some knowledge or perceived wisdom. 

 

For example. Are there any arguments on optimal clock length or is it just the shorter the better? 

 

The SOtM BNC50 cable that they list as an optional $500 extra appears to be 1m for instance whilst there's some controversy around the 40cm internal cable in the TX-USBultra. 

 

Also what are a few of the clock cable brands at different price points that the uninitiated may want to consider? 

 

Lastly are there any clock cable best practices or add ons to consider like ferrites etc? 

 

Cheers, 

Alan 

Synergistic Research Powercell UEF SE > Sonore OpticalModule (LPS-1.2 & DXP-1A5DSC) > EtherRegen (SR4T & DXP-1A5DSC) > (Sablon 2020 LAN) Innuos PhoenixNet > Muon Streaming System > Grimm Audio MU1 server > (Sablon AES) Mola Mola Tambaqui DAC > PS Audio M1200 monoblocks > Salk Sound Supercharged Songtowers

Link to comment

Thanks @auricgoldfinger,

 

Cheers, 

Alan 

Synergistic Research Powercell UEF SE > Sonore OpticalModule (LPS-1.2 & DXP-1A5DSC) > EtherRegen (SR4T & DXP-1A5DSC) > (Sablon 2020 LAN) Innuos PhoenixNet > Muon Streaming System > Grimm Audio MU1 server > (Sablon AES) Mola Mola Tambaqui DAC > PS Audio M1200 monoblocks > Salk Sound Supercharged Songtowers

Link to comment

On the sCLK-EX boards that is used in sms 200 Ultra and tX-USBultra are the masterclock inputs 50ohm and 75ohm  always active even if it is bought without a masterclock input?

 

Main system
TAD D1000mk2, TAD M2500mk2, TAD CE-1, Ansuz Mainz 8 C2, Ansuz Darkz D-TC, 
Qobuz Studio -> Roon ROCK on NUC -> Uptone etherREGEN -> dCS Network Bridge -> AES/EBU -> DAC
HD Plex 200W PSU (4 rail for ISP fiber, router, etherREGEN and NUC)
 
Second system
Qobuz Studio -> Devialet Silver Phantom, Devialet Tree
Link to comment
27 minutes ago, octaviars said:

On the sCLK-EX boards that is used in sms 200 Ultra and tX-USBultra are the masterclock inputs 50ohm and 75ohm  always active even if it is bought without a masterclock input?

 

I recall that @zoltan mentioned in another thread that they are configurable via firmware.  This was regarding a slightly different point, can the unit be swapped between 50 and 75ohm, for which the answer is no, they are factory configured by firmware.  I guess it is just possible that one tap is configured?  Unlikely though, I would have thought.

Windows 11 PC, Roon, HQPlayer, Focus Fidelity convolutions, iFi Zen Stream, Paul Hynes SR4, Mutec REF10, Mutec MC3+USB, Devialet 1000Pro, KEF Blade.  Plus Pro-Ject Signature 12 TT for playing my 'legacy' vinyl collection. Desktop system; RME ADI-2 DAC fs, Meze Empyrean headphones.

Link to comment

I

2 minutes ago, Confused said:

I guess it is just possible that one tap is configured?  Unlikely though, I would have thought.

 

I suppose that the masterklock input needs to be selected in firmware either 50 or 75 ohm input otherwise it would be easy to open it and put in a cable by yourself without the need of SOtM to do anything.

 

 

Main system
TAD D1000mk2, TAD M2500mk2, TAD CE-1, Ansuz Mainz 8 C2, Ansuz Darkz D-TC, 
Qobuz Studio -> Roon ROCK on NUC -> Uptone etherREGEN -> dCS Network Bridge -> AES/EBU -> DAC
HD Plex 200W PSU (4 rail for ISP fiber, router, etherREGEN and NUC)
 
Second system
Qobuz Studio -> Devialet Silver Phantom, Devialet Tree
Link to comment
On 2018. március 14. at 2:00 PM, Confused said:

I recall that @zoltan mentioned in another thread that they are configurable via firmware.  This was regarding a slightly different point, can the unit be swapped between 50 and 75ohm, for which the answer is no, they are factory configured by firmware.  I guess it is just possible that one tap is configured?  Unlikely though, I would have thought.

This is correct as fas as I know. When I sent my SMS-200 ultra to Korea for clock input/output upgrades, I was charged extra for the programming of the board to accomodate the changes.

HQplayer - NAA - Devialet D-800 - YG Acoustics Carmel + dual ELAC sub-2090

Link to comment

Looking at the picture of the tX-USBultra board that was posted earlier, I presume units that have the 75 ohm optional connection will connect internally in the connector circled here.  (circled in blue)  Is this an MCX connector? 

 

I am thinking about the internal clock cable length issue and trying to work out the best proposal to modify.  I am thinking that if you have to have a length of internal cable, you might as well have a 'fly lead' approach and connect direct from the reference clock (via a BNC connector) to the connection on the board.  An overall cable length of 0.6m or 1m should be fine if the reference clock is adjacent to the SOtM unit.

 

Any ideas?  To be clear, this is not my area of expertise!  So all (sensible) suggestions welcome.

clock.PNG

Windows 11 PC, Roon, HQPlayer, Focus Fidelity convolutions, iFi Zen Stream, Paul Hynes SR4, Mutec REF10, Mutec MC3+USB, Devialet 1000Pro, KEF Blade.  Plus Pro-Ject Signature 12 TT for playing my 'legacy' vinyl collection. Desktop system; RME ADI-2 DAC fs, Meze Empyrean headphones.

Link to comment
3 minutes ago, Confused said:

Looking at the picture of the tX-USBultra board that was posted earlier, I presume units that have the 75 ohm optional connection will connect internally in the connector circled here.  (circled in blue)  Is this an MCX connector? 

 

Yes the 75ohm is a MCX connector. Geting a 75ohm cable of decent quality with a MCX connector at one end and a BNC that fits the masterclock seems to be a good idea.

 

Are the 50ohm and 75ohm masterclock available at the same time or does SOtM program the card to accept either one?

 

Main system
TAD D1000mk2, TAD M2500mk2, TAD CE-1, Ansuz Mainz 8 C2, Ansuz Darkz D-TC, 
Qobuz Studio -> Roon ROCK on NUC -> Uptone etherREGEN -> dCS Network Bridge -> AES/EBU -> DAC
HD Plex 200W PSU (4 rail for ISP fiber, router, etherREGEN and NUC)
 
Second system
Qobuz Studio -> Devialet Silver Phantom, Devialet Tree
Link to comment

Windows 11 PC, Roon, HQPlayer, Focus Fidelity convolutions, iFi Zen Stream, Paul Hynes SR4, Mutec REF10, Mutec MC3+USB, Devialet 1000Pro, KEF Blade.  Plus Pro-Ject Signature 12 TT for playing my 'legacy' vinyl collection. Desktop system; RME ADI-2 DAC fs, Meze Empyrean headphones.

Link to comment
11 hours ago, Confused said:

 

But dont you need a male BNC at the end to fit directly to the masterclock? Or was you just talking about changeing the cable inside the SOtM products?

 

1200px-BNC_connector_50_ohm_male.thumb.jpg.2e01a875a3b07528db12fd63665db35a.jpg

 

Main system
TAD D1000mk2, TAD M2500mk2, TAD CE-1, Ansuz Mainz 8 C2, Ansuz Darkz D-TC, 
Qobuz Studio -> Roon ROCK on NUC -> Uptone etherREGEN -> dCS Network Bridge -> AES/EBU -> DAC
HD Plex 200W PSU (4 rail for ISP fiber, router, etherREGEN and NUC)
 
Second system
Qobuz Studio -> Devialet Silver Phantom, Devialet Tree
Link to comment
4 hours ago, octaviars said:

 

But dont you need a male BNC at the end to fit directly to the masterclock? Or was you just talking about changeing the cable inside the SOtM products?

 

1200px-BNC_connector_50_ohm_male.thumb.jpg.2e01a875a3b07528db12fd63665db35a.jpg

 

Yes, in my last post I was just referring to a possible "like for like" replacement for the 0.6m cable inside the SOtM unit.  Like for like but shorter, that is.

 

I am just thinking about possible, practical, solutions at the moment, to see if anything comes out on top as the best approach.

Windows 11 PC, Roon, HQPlayer, Focus Fidelity convolutions, iFi Zen Stream, Paul Hynes SR4, Mutec REF10, Mutec MC3+USB, Devialet 1000Pro, KEF Blade.  Plus Pro-Ject Signature 12 TT for playing my 'legacy' vinyl collection. Desktop system; RME ADI-2 DAC fs, Meze Empyrean headphones.

Link to comment

In terms of the "fly lead" approach, so connecting direct between the clock output and the SOtM board, I have found these two candidates:

 

https://www.amazon.co.uk/24inch-Cable-Straight-75ohm-Right/dp/B071D2F41J/ref=sr_1_fkmr0_2?ie=UTF8&qid=1521638042&sr=8-2-fkmr0&keywords=mcx++to+bnc+0.6m+75+ohm

 

https://www.ebay.co.uk/itm/1-X-24inch-RF-Coax-Cable-MCX-Male-Plug-Straight-to-BNC-Male-Plug-75ohm-Right/272837402958?hash=item3f8660614e:g:9i0AAOSwP8BZsO32

 

I am not sure if the "right angle" connectors are an issue, but that is about all I can find.

Windows 11 PC, Roon, HQPlayer, Focus Fidelity convolutions, iFi Zen Stream, Paul Hynes SR4, Mutec REF10, Mutec MC3+USB, Devialet 1000Pro, KEF Blade.  Plus Pro-Ject Signature 12 TT for playing my 'legacy' vinyl collection. Desktop system; RME ADI-2 DAC fs, Meze Empyrean headphones.

Link to comment
On ‎24‎/‎03‎/‎2018 at 6:21 PM, zoltan said:

If my unit was 75 ohm (as it is not), I would choose something like this: 
https://www.fairviewmicrowave.com/mcx-plug-bnc-male-cable-rg316-coax-fmc0708315lf-p.aspx 

Perhaps 24 inches and that would be enough for both inside the unit and to the clock.

 

Unfortunately, the choice for 50 ohm cables is much more limited.

I do like this idea.  There is much debate about the influence of the external clock cable, but maybe the best approach is to simply eliminate it.  24" is definitely long enough to connect if the clock and SOtM kit are side by side, consider that I am using a 12" cable between the tX-USBultra external connector and REF10, so 24" overall would work fine. 

 

That said, I think using a shorter internal cable is the neater approach.  (and probably better for retaining second-hand resale value) 

 

With either approach, obviously changing internal cables risks invalidating the warranty.  So is this worthwhile?  Will it really make any difference to sound quality?  I plan to experiment myself by swapping between the 12" and 24" cables that I already have.  This test will need to wait a while though, I have changed so much in my system recently that need to spend some time just getting used to it.  The more I listen, the more I realise has changed since adding the REF10 and SOtM kit, so experimenting with  the really subtle stuff is on hold for now!

Windows 11 PC, Roon, HQPlayer, Focus Fidelity convolutions, iFi Zen Stream, Paul Hynes SR4, Mutec REF10, Mutec MC3+USB, Devialet 1000Pro, KEF Blade.  Plus Pro-Ject Signature 12 TT for playing my 'legacy' vinyl collection. Desktop system; RME ADI-2 DAC fs, Meze Empyrean headphones.

Link to comment

50 Ohm from SAEC, reasonable prices. YEN33,000 for 1.5m.

 

Conductor cross section area: 1.22 sq (mm 2 )
sp.gif
Conductor insulating material: EPTFE
sp.gif
Primary shield: Silver plated high purity copper wire
sp.gif
Secondary shield: Tin plated high purity copper wire
sp.gif
Sheath: PVC
sp.gif
Characteristic impedance: 50 Ω
sp.gif
Capacitance: 84 pF / m (1 kHz)
sp.gif
Cable outer diameter: φ 6.5 mm
sp.gif
Plug: Tajimi BNC plug
sp.gif
Cable length: 0.7 m / 1.0 m / 1.5 m

 

 

dig-t50.jpg

AS Profile Equipment List        Say NO to MQA

Link to comment

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...