Rubidium Clock

Can anyone advise whether an Esoteric Rubidium clock would improve the sound on my Esoteric X-01/D2 player? I have been told "not much since it is a one box." But the reviews have seemed to indicate that the upgrade in sound quality is quite apparent. I am aware that some upgrades are very small in their ability to be heard, others are like a whole new piece of gear.
Any advice is appreciated.
I have a P03.

My experience is that while significant, it is not like a new piece of gear.

There is a "rightness" in timbre and pace with the G0rb that you miss as soon as it is out of your system.

I have a G-Os Rubidium clock and it makes a pretty big difference in the quality of the sound - I agree with Randy above. The amount of change you hear is system-, room-, music- and listener- dependent, however. It might be significant in your situation, or it might not be.

It IS in mine. I get a bit more depth of soundstage, air around the instruments and overall musicality with my clock. Best bet is to try to demo one and listen for yourself.
thank you guys for your extremely helpful answers. I will be able to do an audition and will post my perceptions.
I just heard this combination yesterday. There was a definite improvement in the sense of real insruments and voices in space, and diminished "splash" on transients like cymbals and applause. The character of the sound changes less than what you hear when switching between the DSD and multiple-bit DACs, but whereas I think the DSD/multibit choice is a matter of preference, it's pretty obvious that the clock's impact is better, vs. just different.

I'll take a stab at quantifying the impact, and say that the effect on redbook is about 25% of the way from redbook to SACD, possibly a bit more.

I also listened to the $5k model ( G03X), and this much less expensive model is very nearly as effective. I didn't try to compare clocks to each other because frankly, I can't afford the G0Rb unless I win the lottery. As far as the G03X, if I had the cash, I would taken one home, but alas, it will have to wait . . .
you can buy a SRS PERF10 for around $3000, the rubidium clock "box" inside is better than the Esoteric or the Antelope.
Are you referring to SRS FS725?
The SRS FS725 is the older, simpler version of the Stanford Research Systems rubidium clock.
The PERF10 has a nicer box and a power switch, but the same internal clock as the SRS FS725

If you get the SRS rubidium clock, you still need to get an Antelope Isochrone OCX master clock which outputs 44.1K. The Rubidium clock acts as an external clock to the Antelope

YMMV but together I have found that these 2 clocks can make a big difference at considerably lower cost than the Esoteric rubidium clock which I have not heard. And power cord and digital IC choices can also make a meaningful difference raising the overall cast.
Thanks for the great info. I will need to try one of those.
I've done a lot more research in this regard and have had a number of conversations with SRS as well as other options. The lead-time on the PERF10 or FS725 is longer than I would like to wait personally and my RFQs out to LibertyTest, AllTest and other certified/used equipment vendors for a PERF10 or FS725 have come up dry at the present time. I stumbled on Cybershaft Japan as an option via listings on various sites. It seems they make OCXO, Rudidium-only and OCXO+Rb clock units (single port each standard) for high-end audio, video and studio purposes at an extremely aggressive price point (the Rb-only unit is about $1300-$1500 USD depending upon JPY->USD conversion rate). They are rated for 100-120V and 50-60Hz use which makes them perfect for US or Japanese usage. The Rb-only unit has a single FIFTY (50)-ohm BNC clock output; they supply all their test and calibration results with each unit plus a 1 year unconditional warranty.  I have taken the plunge and ordered one as of yesterday; this should be a very nice and affordable test.  I plan to use this 10Mhz reference clock sync to drive my Esoteric D-02's clocking baseline while leaving the D-02 to sync itself and the P-02 transport together at 22.5792 Mhz.  This should surpass the already great performance of the D-02 clock circuit by a clear margin.  Unlike the PERF10 or particular FS725, this Cybershaft unit seems to have a better internal PSU but I'm not discounting the potential move to another HDPlex power supply with a retrofit in the future to get an even better bespoke PSU to drive the Rb-clock.  I will report back and let you know my findings between mid-late April after I receive it and break it in.  They state specific compatibility with Esoteric D-02, D-03, D01, G-01, G-02, G-03x, G-02s, K-01, K-01X, K-03 and K-03X.  You may read more here (use Google Chrome and let it translate the page);

www dot cybershaft dot jp
There are many relatively inexpensive scientific instrument versions with 50 ohm outputs. I could find none with a 75 ohm output, as needed for optimal impedance match with 75 ohm digital audio input as used on the Esoterics. Through a web search I found posts and screen shots by an engineer who measured a degraded 10Mhz waveform caused by reflections between mismatched 50 & 75 ohm BNC impedances. That was enough for me to pony up the added $$$ for the SRS.
The 10Mhz inputs on the Esoteric gear is spec'ed at 50-ohm, not 75-ohm. The "WORD CLOCK" In and Out BNC connections on Esoteric gear is spec'ed at 75-ohm.  Put another way, if you use an atomic/other external clock standard to supply a 10Mhz pulse, Eso gear expects that at 50-ohm whereas for Word clock purposes (44.1, 88.2, 176.4, 22.5792Mhz), they expect 75-ohm...
The K-01X manual specifies the BNC clock input as 75 ohm impedance.  I can't speak to other Esoteric products.
Correct in the case of the K-01X; it only has a WORD CLOCK IN connector which is 75-ohm (as with other Eso gear). It does not have a separate 10Mhz input.
In the way of an update, I have the Cybershaft Rb+OCXO 'dual master clock' offering up and running as of late and I am extremely impressed by the build quality of the unit and the customer service provided by Hasegawa-san at Cybershaft.  He goes to great lengths to ensure all questions are answered and provides unit-specific test data for ALL testing of the unit including Allen Deviation, reference measurement devices used, etc....It's the most specific and open backing of what a unit truly does after it is built I have ever seen.  The price point of the unit is a fraction of the other offerings in the space (that provide 10 Mhz atomic-precision master clocking) and frankly when I saw the unit, it's quality, appearance and sheer weight coupled with the exceptional customer service, I don't fee that I am missing out on a single thing compared to the offerings from Stanford Research, Isochrome/Antelope or others. I currently have this connected as follows;

Cybershaft Rb-output=>10Mhz=>Esoteric D02 (WRD CLK IN, 10Mhz)=>Esoteric P02 (MCLK frequency from the D02). 

Put another way, the Cybershaft clock is providing an atomic-precision baseline for the clocking circuit of the D02.

All the specs and other technical aspects aside, there was an immediate improvement in the natural/liquid nature of the sound when I enabled the 10Mhz input signal from the Cybershaft to drive the WRD CLK Input of the D02 over the D02 alone. All was extremely good before but I find a touch more precision in image size and placement (of instruments and voices) and an even more musical presentation overall of the system as a whole.

I am very happy to have stumbled on the company out of Japan that as it turns out produces alot of these and similar devices for broadcast and recording audio and video firms and audiophile users in Asia.  My hat is off to Hasegawa-san and his team for building on hell of a component at a fair price and topping that with some of the best customer service and attention to detail I have ever seen!
Fascinating find. I may have to consider this to work with Mutec 3+usb converter.  Can you please let me know the part # of what you purchased? 
Good Day tboooe!!! Great to hear from you,...hope all is well!

The model number is RBOCXO-01,...send me an in-mail with your current email address and I'll be happy to share the calibration data and manual from the specific unit I now have.
Thank you zephyr!  Things are good thank you!  I hope all is well with you too!  I am really happy to have found this thread as I have been thinking about adding a clock to my system.  Actually I was thinking about this waaay back when I still had my Esoteric P3-D5 combo.

I am a little embarrassed to ask this question but what is the difference between the 10M clock like this one from Cybershaft and a work clock like the Esoteric G-01?  Also, the Cybershaft websites states that it is ok to plug their 50ohm output into a 75ohm input of the downstream device.  Is this correct?  

Again thank you zephyr!

The newer X version over the non-X or your D-02 uses the same clock input connecting, however, it is menu selectable to accept 10M input as well as a masterclock input of 22M (the new D-02x has this function.

The Rakon OCXO used in the cybershaft has impressive specs (possibly delivering better short term phase noise) as opposed to any Rubidium module. Not sure if sonics, beats say the G-01.

Maybe Hasegawa-san has tested or compared.

The benefit is the capability of running the master 22M from the G-01 directly to the newer Esoteric players/Dacs. Essentially bypassing all clock circuits of the player/Dac.

I believe that a separate clock, whether a 10M or G-01 unit has over the internal clock of the Esoterics is much more attention and contribution is made by the beefier power supply lacking in the players/dac.

tboooe: Thanks for dropping me an in-mail,...hope you've had a chance to review the Rb and OCXO calibration/test and Allan Deviation plots for the Cybershaft clock; let me know if you have any questions.  I'm very happy to find a 10Mhz master clock that doesn't break the bank and yet delivers superior quality.  It's not the G-01 in cost or in its ability to send other 44.1 frequency multiple clock frequencies, or 22.xx or 24.xx "direct master clock" frequencies but what it does do very well is a rock solid 10Mhz high-precision pulse output to help up the performance of my D-02 clocking itself and the P-02 together.  I've just crossed 310 hours or so and things have matured nicely so I am very happy with this path I've chosen.  

Insofar as the 50-ohm versus 75-ohm cable question is concerned, the Esoteric P-02 and D-02 manuals are explicit in that both terminal types are available and should be used with the matching cable depending upon configuration desired.   I've done a good amount of research and in threads here, links referenced externally by posts here and on other sites, I've read that it does introduce errors and anomalies if you try to utilize a 75-ohm cable where a 50-ohm connection is specified. It's true that you 'can' do it, and a small number of people report that they do hook-up this way (mostly because none of the high-end cable firms seems to make a high-quality 50-ohm cable) but from all I've read, it can/does have some negative affect on the overall sound of the configuration.  Therefore, I'm running 75-ohm cabling where it belongs and did procure a good quality 50-ohm cable from Cybershaft to hook up the master clock to my D-02.  Joe Kubala is building a proper 50-ohm version of his "Emotion" digital cable for me and I should have that in about 2 weeks; I'm looking forward to matching the quality of my existing 75-ohm clock cable!

justubes2: Apologies for the delay in replying and thank you for all the useful info on the D-02X (and together with the P-02X) as well as your observations!  I had not read up on the X versions of the P-02 and D-02; they look impressive to say the least; they've added ESLink4 and many more capabilities and internal build from the P1 and D1 generation. The upgrade would be major based upon what I read though I need to stick with my current units for 'a while'.  

If you send me an in-mail and let me know your external email address, I'd glad share the detailed calibration test results for my units dual clock modules and the separate Allan Deviation test reports.  From what I can see, the Rubidium seems to have a bit of an edge in overall precision with lower Harmonic distortion (very small margin) but higher overall phase distortion versus the OCXO module (which appears to have extremely low phase distortion), so it's going to be a tough choice overall to select my 'final config' as to which circuit to utilize. The Rubidium side SEEMs to have better overall Allan Deviation performance but as I'm no expert at this (reviewing such data), if you want to have a look at the very detailed reports, I'm happy to share them and get your opinion.

I did check out the config options on my current P02 and D02; the D02 does offer the ability to config either a 10Mhz input as well as (one or the other at any one time), a master clock input; I think what your reference for the X versions is also present on the P-02 and D-02 based what I've just seen again in the config menus.  The D-02 also offers a "THRU" clocking mode that allows me to take a 10Mhz pulse into the D-02 on the 50-ohm connector and (while clocking the D-02 to it), pass it through directly to the P-02 (but on the 75-ohm Word Out/In) if I wanted to have both units fully clocked only on a 10Mhz baseline.  The way I do have it setup though is that I have 10Mhz baseline come into the D-02 on its 10Mhz input and then use "MCK" direct master clock frequency output of 22.xx Mhz from the D-02 to the P-02.  So far, this is the best sounding combination (along with 4fs or 8fs up-sampling of RBCD and S_DLY2 filter which has been my 'go-to' configuration all along.

All this stated, I also don't know how this all compares without going out and plunking down the sizable commitment for a G-01 (or X when they bring it out) and/or using the G-01 AND driving it with a 10Mz reference signal from the Cybershaft.  

Wow....too damned many options to consider :-) ! The life of an audio-nut is never complete I guess as always!
Hi Zephyr,

Thanks for your info on the Cybershaft, i have read the specifications, most impressive, seems 2nd only to the 6X more costly non commercial BVA OCXO which is an end of life product.

It looks to be very impressive where the Rakon's OCXO phase noise surpasses any commercial audio clock!

As to your P-02 / D-02 units, a Masterclock option will likely be  more superior, it believe it is the output feeding of either the P-02 to D-02 or vice versa as your units can act as a Masterclock to feed other units (as such, you will not need to feed 2 separate clock signals to both units).

Are you finding that you are liking the Rubidium output over the OCXO output from the Cybershaft unit?

Thank you for checking all that out and letting me know your thoughts!

I have only been using the Rb 10Mhz output thus far and like it very much. It ups the ante on 'meat/substance" around each note and the overall musical presence.  It's a not so subtle improvement over what the P-02/D-02 with the D-02 set to MCK (22.xx Mhz) output to drive itself and the P-02 are capable of.

I have things setup as follows:

Cybershaft RBOCXO-01 (10Mhz, 50ohm output) into D-02 10Mhz 50ohm input
D-02 set for WORD IN of 10Mz
D-02 set for WORD OUT (75ohm) of "MCK", so 22.xx Mhz
P-02 set for WORD IN (75-ohm), so it gets a Direct MCK pulse from the D-02

Near as I can tell, even with the higher phase noise of a typical Rb circuit baselining the
operation of the D-02 with an atomic-reference/rock-solid 10Mhz pulse is the jump I was
looking for.

I have not tried the super-accurate/low-phase noise OCXO circuit (10Mhz, 50ohm) on the Cybershaft as yet. As the unit has crossed 350 hours as of late tonight, I will switch over and see which config I like best.

I had two Esoteric clocks over the years;

G-0s: Amazing and super-accurate overall system presentation driving the P-03U and D-03 but a touch analytic
G-03x: Not so analytic, accurate sound-staging, etc....just enough precision for my ears

I never drove the G-0s or G-03x with a separate 10Mhz reference pulse clock device....

I later found when I got the D-02/P-02 combo that the D-02 has an improved clock over the G-03x so I parted ways temporarily with a separate clock.

The combination of the 10Mhz Cybershaft and the much improved Direct MCK 22.xx Mhz operational mode of the D-02 driving the P-02 leaves me with the best overall sound I've heard out of any my systems, ever.  

More later as I listen to more combinations!
Good Morning! In the way of any update,....the Cybershaft has well over a 1500 hours on it at this point (and the RB and OCXO clock outputs are equally broken in) and I've done a lot of testing over a wide variety of material (CD, XRCD, SACD) and alot of different recordings.  During this time I've spent several days at a time with the Cybershaft Rb and then the OCX outputs; over the past month I have found myself using only the OCX output circuit for 10Mhz 50ohm output as sonically, it is a much better match for the widest variety of recordings and things simply sound their best over and above what the Rb-based 10Mhz output circuit provides.  At this point, I think it is safe to say that assuming no other changes to the system, that I will be sticking with the current config and using the OCX output over the Rb for playback of 90-95% of all material.  Questions...please let me know.
Justubes2: Thank you once again for highlighting the lower phase noise/etc...on the OCXO side of my Cybershaft clock. The difference in terms of satisfying musical presentation of every note, more precise and natural imaging, etc...once I switched over and have been using that circuit as my 10Mhz baseline is not only noticeable but dramatically better! With the Rb circuit (as with my experiences a few years ago with the Esoteric G-0s Rb clock), I had precision in many ways but not the beauty and naturalness I am experiencing with the lower phase-noise OCXO-based presentation.  Thank you again!!!
Thanks for your posting on the Cybershaft zephyr24069. Nice to know your experience continues to be positive. I have a Premium OCXO in route.
Sibelius: Great to hear from you....what piece will you be driving with the Cybershaft Premium?  I am sure you will be very happy with the result based upon what I continue to hear here plus the results of 2 others who have recently received one of Kenji's premium OCXO 10Mhz units.  On day1 it's an impressive difference,...once the power supply and OCXO get broken in (seems to be the usual 300-350 hours is required) fully, I believe you will be even more happy!  Enjoy....let me know how it turns out for you!

You mentioned something about the HDPlex LPS, do you think it would be possible for Cybershaft to manufacture a unit to accept the power from the HDPlex.
I just contacted Cybershaft and mentioned that I have a few HDPlex LPS units laying around and I'm looking for recommendations for a 10MHz clock for my pair of Grandioso D1.
Hopefully I will hear back soon on the matter.
Ysound: you must have a very nice setup with the Grandioso gear!  For clarity, are you looking to add 10Mhz (50-ohm) clocking externally to baseline the MCL circuits in your D1s? If so, the Cybershaft is definitely worth considering....

To your question: I have no idea whether Cybershaft would produce a unit that takes a DC XLR 5-pin connector (like Wavelet) and would allow you to use an outboard power supply.  That would be a question to send to them directly.  I can tell you that with the power supply that is my the clock I purchased to begin with (designed by Cybershaft for best match and optimal performance), I've never sonically felt a need to look into this path for my setup here. The power supplies in the Cybershaft upper-line clocks are of excellent quality from what I hear out of my system.
Yes, I'm looking to add a external clock to the D1s and then output the clock signal from the D1 to the RedNet D16.
BTW, the RedNet is the real deal, just replaced my USB set up and was amazed of the immediate improvement in SQ, worth every pennies in my opinion. 
Next up, will trying out some of AQ crazy priced CAT6 cables.

ysound - I'll second your recommendation of the RedNet. I also have a D16 and love it.

Zephyr - the Cybershaft is going into an Antelope Liveclock which is then feeding the above mentioned RedNet D16 and a Mutec MC-3+ USB reclocker. I've been very pleased with the outcome.

Sibelius: Thanks for letting me know,..
Interesting discussion. I'm using Oscilloquartz 8607 powered by custom PSU and very happy with results in my Aurender/dcs system. Problem now is availability of 8607 on used market so your option could be very interesting alternative
That looks to be one outstanding OCXO clock module...phase noise and precision specs are really impressive! It reports discontinued unfortunately....this seems to happen alot from what I've seen recently.  I'm told that vendors often will buy up 1500-2000+ units of such a component when they find it and test it/validate its quality just in case. Very similar to what happened alot in the DAC chip market and how some vendors (AMR, others) have chosen to proceed (which is a good approach IMHO).....
Hey Zephyr,

I just had to...... Thanks Zephyr for contributing Cybershaft's excellent OCXO at affordable prices!

Just received from Kenji an option 16, -116db/1 Hz OCXO hand selected/tested from many OCXO's.

The packaging was 1st class all the way, just beautifully well packaged and delivery was just too fast, i hadnt even expected it for another 2-3days. 

I have to run it in, nut off the bat, coming from a Quartzlock rubidium 110db/1 Hz into a G-02, what i am experiencing  exactly echos your comments from switch from rubidium to OCXO.

" I had precision in many ways but not the beauty and naturalness I am experiencing with the lower phase-noise OCXO-based presentation."

The Rubidium has maybe better sparkle or "brightness", not in a really bad way and a bit more pyrotechnics in the bass... I would term it a hardness and some glare which i did not really find distracting with careful tweaks and room adjustments. Rubidium thus lends to a brighter, showy or flashy presentation.

Cybershaft's OCXO is just so much more grounded in the mid regions  and has zero brightness that i can tell so far from any genre's of music now, even "poorer" commercial recordings.

Hi Custodian, i appreciate your comment now of low phase noise from your BVA 8607..."Zero digital glare" from discussion from another forum.

I am not certain is this an combined artifact of low phase noise and also character OCXO as opposed to a rubidium unit.

I guess i have fueled my quest of experiment with clocks. Thanks to all, a most excellent resource in this discussion.
You are very was a very lucky stroke to have come upon this company and their products via HiFiShark and then following over to Yahoo Japan.  Kenji and his team are consummate professionals and have done their best by a few of us who have taken up one or the other of their top clock models into our systems. As Kenji explained to me, the most precise clock is not the end-all/be-all for an audio or video high-quality system; he explains that alot of hardcore testing and real world use cases have proven to him and his team that the best strategy is to come as close as possible to the clocking standard and precision of the original recording. He has also further explained the fallacy (which I was guilty of same as others) of only focusing on "ppm" or "ppb" accuracy to evaluate our purchases of master clocks and to instead look at all the aspects of a clock's performance including Allen Deviation, Phase Noise, truly evaluate how that clock will perform.  Suffice it to say I've learned alot more in the process than I had ever picked up on before and I am glad that what I am hearing insofar as audible differences in my system with the clock is also being enjoyed by yourself and several others who all write about very similar positive experiences with this fine company's products.   Have a great day and Enjoy The Music!
Is the UPOCXO-01-SS clock (OCXO only) equal performance wise to  RBOCXO-01 when in OCXO mode ?
For the standalone OCXO clocks as I understand it from a couple friends who have ordered the Ultra Premium/Premium versions, the answer is that in terms of phase noise being lower, is superior to the Rb-only clock in terms of overall musical presentation.  I cannot speak to their individual results as I was not in their rooms to hear but for my system, with the dual-clock unit using the same parts, power suppliers, etc...and itself and Ultra Premium level unit, I can tell you that I do love what the Rb side does for the system on many discs, however for my ears and most of the discs on my shelves, the OCXO provides a more musical presentation without sacrificing the imaging improvements and other things related to higher-precision clocking. Write on in-mail if you want to talk via phone or email more directly. Apologies for the delayed response as I've been off the forums due to work and life for a few days....
Thanks. I went ahead and ordered the UPOCXO-01-SSSS clock for my friend. We will try it with his Vivaldi stack, on top of the Vivaldi clock.

If it goes well, he may consider the UPOCXO-RK01-OP17 Ultra model, which is triple the price, but also offers 7 dBc/Hz lower phase noise level at 1Hz (-110 dBc/Hz vs -117 dBc/Hz) .
Good luck with breaking in the clock and all the testing; please let us know what you hear and determine about the overall sound with that configuration!
Have anybody tried it with aurender w20 with a word clock input & it already has oxco clocks ? 
Any device you connect to one of the master clocks from Cybershaft should support 50-ohm 10 Mhz master clock connections; note that there is much discussion in a couple of forums as of the last month or two that quotes statements from manufacturers using hard facts that claim that using a 75-ohm cable in place of 50-ohm is acceptable for short runs (1-meter, 1.5 meter, etc...typical between such devices). I happen to be using spec-compliant 50-ohm capables. That stated, the discussion and statements from 3 different clock manufacturers including Esoteric, Cybershaft and one other (think it is SRS or Antelope) state that for a 50-ohm input and output pair, using 75-ohm cables for these lengths does not represent a probable issue.  No discussion I have seen states that you can connect a 75-ohm cable to a 75-ohm input and route a signal (such as one from a Cybershaft clock of SRS PERF10, Antelope Isochrome 10MX, etc..>) made for 50-ohm and 10 Mhz in nature to a 75-ohm port.

I just read the Aurender W20 manual and spec. sheet on line; they are very good in terms of the step by step involved in setting up the server and playback software however, they do not seem to make any statements about how to setup/configure the clock input for what they state they support (from their website and product manual: "It supports both word clock (dCS DACs or similar) or Master Clock.(MSB DACs or similar)"

I would suggest you get specifics from Aurender regarding what this input on their W20 truly supports first and go from there. I’ve sent a question as well using their online form; if I heard back I will let you know.  The key questions;

- is their input a 75-ohm or 50-ohm connect (based upon context on their spec-sheet, I'd guess 75-ohm?
- does it truly support "master clock" frequency of 10 Mhz...?
- how do you configure the W20 to tell it which type of clocking input it is receiving?
Response from Aurender

The W20 supports 44.1kHz clock inputs at 2x and 4x, 48kHz clocks at 2x and 4x, and 10MHz clocks; we also support MSB clock systems. All clocks must use a 75ohm BNC type connector.

If the Cybershaft meets these specifications, then it should work correctly with the W20.

Used to own MSB Select with Femto clock  . Just direct connection without any set up 
In professional studios /  industrial applications of 10M clocking, one may very well see cabling of lengths of 10 meter, 20 meters connection the various equipment.

In his situation, using a 75ohm cable will cause a decrease in voltage reaching the equipment in question, potentially causing locking/syncing problems or possibly not locking at all.

There would not have these issues typically over shorter lengths of 1 meter even if there IS a voltage drop, but to a lesser degree and still capable of locking.

Now, say for the Aurrender W20, there is 1 bnc clock connector, 75 ohms presumably. This would be correct for 44.1, 48khz or multiples, BUT not for a pure 10m sine input. 

10M sine signal, you would want a 50 ohm cable

10M TTL signal, you would want a 75 Ohm cable.

More clarification is required from Aurender, even so the bnc on the unit may have only been considered for TTL Levels.

Sure, the unit will still most likely lock with a 50 ohm cable.
Thank you both for the was Aurender's response to my questions yesterday. I've included it as they put a bit of additional detail/wording;

"- The BNC input is 75ohm only, and does not support a 50ohm connection.

- The input supports 44.1kHz 2x and 4x, 48kHz 2x and 4x, and 10MHz. It also supports MSB’s work clock frequencies. These are typically automatic, though they may need to be adjusted by the user on the manufacturer’s clock, manually (Esoteric, for example). MSB uses proprietary clock frequencies which we are compatible with. dCS uses either 44.1kHz (2x and 4x) or 48kHz (2x and 4x).

- Based on the above, we should work with any clock system that uses a 75ohm BNC connector and operates at any of these frequencies. We do know that Esoteric clocks require a manual adjustment by the user."

There was additional exchange with Aurender Tech/Sales Support. Here is the complete synopsis from the beginning....

“10 Mhz clock signals are also valid as per my previous email. The app allows adjustment between 44.1kHz or 48kHz, whereas 10Mhz is auto detected and is a single frequency.” <Aurender>

Question: “What about 10 Mhz per your last email, your most recent email excludes it from the list”

“The word clock input is activated in the Settings menu of the app, and the word clock is automatically turned on when a word clock signal is detected on the BNC input. When word clock mode is on, the SPDIF output will synchronize with the word clock signal. For a 44.1, 88.2 and 176.4 kHz sampling rate, 44.1, 88.2 and 176.4 kHz word clock or a 22.5792 MHz master clock signal are valid. For a 48, 96 and 192 kHz sampling rate music. 48, 96 and 192 kHz word clock or a 24.576 MHz master clock signal are valid.”<Aurender>

Question: “How do you configure the W20 to know what frequency it is to expect? Is it auto-sense?”

“With regard to your questions about the W20 word clock input, please refer to below -

- The BNC input is 75ohm only, and does not support a 50ohm connection.

- The input supports 44.1kHz 2x and 4x, 48kHz 2x and 4x, and 10MHz. It also supports MSB’s work clock frequencies. These are typically automatic, though they may need to be adjusted by the user on the manufacturer’s clock, manually (Esoteric, for example). MSB uses proprietary clock frequencies which we are compatible with. dCS uses either 44.1kHz (2x and 4x) or 48kHz (2x and 4x).

- Based on the above, we should work with any clock system that uses a 75ohm BNC connector and operates at any of these frequencies. We do know that Esoteric clocks require a manual adjustment by the user (to set the output clock frequency)

I hope that helps and please let us know if you have any other questions.” <Aurender>

Question: “…One aspect that is very important to me is to integrate into a system that makes use of Esoteric (Japan) P-02 Transport, D-02 DAC, G-01 master clock (75-ohm re-clocking/master clocking) and a separate Rb/OCXO (dual capability)10 Mhz 50-ohm "Master Atomic Clock".  

Your website and user manual does not give more specific info on the BNC Word Clock input on the W20.   Can you please let me know;

- is it 75-ohm or 50-ohm input?- what frequencies does it support (44.1, 88.2, 176.4, etc...)?- does is also support 10 Mhz master clock input?- how do you configure which type of input is coming into this port?

Your website say this;

‘... It supports both word clock (dCS DACs or similar) or Master Clock.(MSB DACs or similar)...’

*Can you please give specifics on what this means? For example, what is the difference between DCS DAC and MSB DAC clock outputs. Have you tested with any of the following;  Esoteric G-01 (Rb oscillator)- Esoteric G-02 (OCXO)- Esoteric G-03x (OCXO) Antelope Isochrome 10MX- Standard Research SRS PERF10- etc…?”