Clock experiments

[custodian]

Over the last year, I've been using a special rubidium clock as master clock for my DCS system. The clock is a prototype from one of the leading digital timing companies in which they synch rubidium with an ocxo to get the benefits of both.

Because this was such a step up from the standard Scarlatti and Vivaldi clocks, I decided to investigate what further refinements in clock accuracy were possible. Last week I received here a prototype clock using a BVA crystal. This is the ultimate development of the OCXO to improve phase noise by an order of magnitude.

Results? A huge increase in sound quality through a reduction of remaining digital edge. I am amazed how much cleaner the sound is. Sound has an analogue sweetness but with great resolution.

Downsides? Two main ones. First cost: the only commercial example made for the HiFi world is $35k although should be possible to build one for nearer $10-15k; second drawback is stabilisation is quite slow, typically 48 hours to get to peak performance.

It really is surprising how big an effect these timing refinements can make to sound quality.

[Robert_Anderson]

Will an Esoteric clock work with your system? Mine was around 16K, it made a significant difference with my Esoteric separates. 35K for rubidium clock seems absurd. I use them in the radar system I manage and they are closer to 5K.

[custodian]

You misread my post. I have replaced the rubidium clock with a BVA clock. A different animal altogether. Short term accuracy is an order of magnitude ahead of the Esoteric clock!

[marsalis]

Can you provide some more info on the BVA clock?

[custodian]

It's a prototype built around an Oscilloquartz BVA8607b double oven OCXO mounted in a damped enclosure with a stiff power supply. A bit of a bench top prototype but not so difficult to turn into a finished product.

[jfrech]

Very interesting post. I've been creeping up the dCS stack...I know the clock and the clock cables make a BIG difference. I've used the dCS U Clock and currently the dCS Scarlatti Clock.

Clock cables i've tried are the stock dCS, Cardas Lightning 15 (excellent value and smashes the stock cables), Purist Proteous Provectus Praesto and now Transparent Ref XL digital.

All BNC to BNC

Speakers: Rockport Altair 2
Preamp: Robert Koda K10 Amp: Ayre MX-R
Cables: Transparent Opus MM2 Spkr, Opus MM2 & Trans Ref MM MM2 Intcnct.
Power Shunyata Triton/Typhon, Anaconda Zitron cords (x9)
Digital dCS Vivaldi DAC & dCS Scarlatti Clock & Transport with Transparent Reference XL Digital cables
Phono: Grand Prix Monaco TT, Schroder LT arm, Jan Allaerts MC2 Finish & Lyra Atlas, Nagra VPS/VFS
Racks: Grand Prix Audio Silverstone F1 (x2)

[custodian]

Very interesting post. I've been creeping up the dCS stack...I know the clock and the clock cables make a BIG difference. I've used the dCS U Clock and currently the dCS Scarlatti Clock. Clock cables i've tried are the stock dCS, Cardas Lightning 15 (excellent value and smashes the stock cables), Purist Proteous Provectus Praesto and now Transparent Ref XL digital. All BNC to BNC Speakers: Rockport Altair 2 Preamp: Robert Koda K10 Amp: Ayre MX-R Cables: Transparent Opus MM2 Spkr, Opus MM2 & Trans Ref MM MM2 Intcnct. Power Shunyata Triton/Typhon, Anaconda Zitron cords (x9) Digital dCS Vivaldi DAC & dCS Scarlatti Clock & Transport with Transparent Reference XL Digital cables Phono: Grand Prix Monaco TT, Schroder LT arm, Jan Allaerts MC2 Finish & Lyra Atlas, Nagra VPS/VFS Racks: Grand Prix Audio Silverstone F1 (x2)

There are big improvements to be had by installing a master clock with higher short term accuracy than the DCS clock. Certainly clock cables also worth experimenting with. I've had good results with the Vertex range although they are not well known in the USA. Apart from those, my cables of choice are Siltech with MIT for power to digital components. But do improve the clock before the cables: there's more to be gained with doing that.

[joeling]

Are u talking about the master clock or the reference clock ?

[Robert_Anderson]

You misread my post. I have replaced the rubidium clock with a BVA clock. A different animal altogether. Short term accuracy is an order of magnitude ahead of the Esoteric clock!

Sorry about that, I will have to look into it.

[custodian]

Are u talking about the master clock or the reference clock ?

I'm talking about adding an external reference in addition to the DCS clock. The additional clock outputs a reference 10mHz signal which the DCS clock locks to rather than its own Clock.

[Garth]

At those prices you have just forfeited your rights to making comments on the cost of Analog. :music:

[custodian]

At those prices you have just forfeited your rights to making comments on the cost of Analog. :music:

Not something I have any interest in, having sold my Goldmund Studio and 5000 records many moons ago. These days even the hassle of dealing with thousands of silver disks is beyond me. Anything that can't be selected and managed from my iPad is far too much hassle!

[joeling]

custodian,

Thanks for the info. Any chance this will become a commercial product ?

I am using the Antelope clock & it does make a difference.

Regards,
Joe Ling

[custodian]

custodian, Thanks for the info. Any chance this will become a commercial product ? I am using the Antelope clock & it does make a difference. Regards, Joe Ling

The Antelope rubidium clock has quite poor phase noise. There are much better rubidium clocks available with improved phase noise and the BVA clock is an order of magnitude better again.

There is no problem in producing as BVA clock for HiFi use apart from cost. Having looked at costings, I think it would be at least $20k, maybe a bit more. Do you think there would be a market at that level?

[joeling]

Anything commercially available at the moment better than the Antelope ?

[custodian]

Anything commercially available at the moment better than the Antelope ?

I'll have a look at which rubidium clocks are used in the commercial units and get back to you. From memory, I think the Esoteric one uses a clock with better phase noise but I need to check. There is a commercial BVA clock for HiFi use made in Japan which retails at $35k but I think I could do an equivalent one for half that cost.

[custodian]

The longer the BVA clock operates, the better the phase noise performance. I must say the clock change to BVA has produced a staggering improvement in quality.

[Davidny]

I have been using the Antelope Audio OCX clock master clock and a Stanford Research Systems Rubidium 10MHz oscillator (FS725). A material improvement to the internal clock of my Soulution 745 SACD/CD player. Interconnect and power cables also make a noticeable difference.

[Masterlu]

Davidny... Welcome to AA! :wave:

[jfrech]

The longer the BVA clock operates, the better the phase noise performance. I must say the clock change to BVA has produced a staggering improvement in quality.

I am very curious here. I have the Vivaldi Transport ordered...hopefully it'll be here in a week or so. I have kept my Scarlatti clock for the time being...I got to demo the Vivaldi Trans...and it made quite a difference in my system vs my dCS Scarlatti Trans...I don't know if the Vivaldi Clock...the clock specs to the Scarlatti are the same..the Vivaldi clock adds dual frequency outputs...which can be useful (but I can get the same results by pressing a button on Scarlatti to change the frequency and don't have to buy another cable)

Using the reference clock input I've always been curious about...

Speakers: Rockport Altair 2
Preamp: Robert Koda K10 Amp: Ayre MX-R
Cables: Transparent Opus MM2 Spkr, Opus MM2 & Trans Ref MM MM2 Intcnct.
Power Shunyata Triton/Typhon, Anaconda Zitron cords (x9)
Digital dCS Vivaldi DAC & dCS Scarlatti Clock & Transport with Transparent Reference XL Digital cables
Phono: Grand Prix Monaco TT, Schroder LT arm, Jan Allaerts MC2 Finish & Lyra Atlas, Nagra VPS/VFS
Racks: Grand Prix Audio Silverstone F1 (x2)

[custodian]

The DCS clock is a standard OCXO of pretty good spec.

Using the master clock input on the DCS clock, you can use an external master clock which might improve sound.

Options for master clock are:

1. GPS clock - not a good choice because of poor short term stability

2. Rubidium clock- can be a real improvement however basic rubidium also has poor short term stability and you really need something where rubidium and OCXO are working together to get better performance.

3. BVA OCXO clock which is ultimate short term stability but at a price. Only commercial unit designed for audio use costs $35k!

BVA really makes a huge difference to sound quality in removing any hint of digital edge.

[JCR]

I am very curious here. I have the Vivaldi Transport ordered...hopefully it'll be here in a week or so. I have kept my Scarlatti clock for the time being...I got to demo the Vivaldi Trans...and it made quite a difference in my system vs my dCS Scarlatti Trans...I don't know if the Vivaldi Clock...the clock specs to the Scarlatti are the same..the Vivaldi clock adds dual frequency outputs...which can be useful (but I can get the same results by pressing a button on Scarlatti to change the frequency and don't have to buy another cable)

Using the reference clock input I've always been curious about...

Speakers: Rockport Altair 2
Preamp: Robert Koda K10 Amp: Ayre MX-R
Cables: Transparent Opus MM2 Spkr, Opus MM2 & Trans Ref MM MM2 Intcnct.
Power Shunyata Triton/Typhon, Anaconda Zitron cords (x9)
Digital dCS Vivaldi DAC & dCS Scarlatti Clock & Transport with Transparent Reference XL Digital cables
Phono: Grand Prix Monaco TT, Schroder LT arm, Jan Allaerts MC2 Finish & Lyra Atlas, Nagra VPS/VFS
Racks: Grand Prix Audio Silverstone F1 (x2)

jfrech, according to my dealer the Vivaldi clock is better then the Scarlatti. I have not tried both but when they did the Vivaldi, they improved the internal circuits and power supply compared to the Scarlatti.

[JCR]

The DCS clock is a standard OCXO of pretty good spec.

Using the master clock input on the DCS clock, you can use an external master clock which might improve sound.

Options for master clock are:

1. GPS clock - not a good choice because of poor short term stability

2. Rubidium clock- can be a real improvement however basic rubidium also has poor short term stability and you really need something where rubidium and OCXO are working together to get better performance.

3. BVA OCXO clock which is ultimate short term stability but at a price. Only commercial unit designed for audio use costs $35k!

BVA really makes a huge difference to sound quality in removing any hint of digital edge.

This is indeed an very exciting topic as pointed earlier in this thread. I am confused on this topic as a year ago I did experiment with the Antelope Rodium reference clock with my Vivaldi stack. At first I was impressed but after a few days of listening I felt the sound was colored a bit and could not understand why.

I called dCS directly since I had met the rep and he then had told me dCS apparently a while back looked into reference clock ... in the case the Antelope, he suggested its switching power supply was not ideal and even if you feed the dCS clock with a perfect 10Mhz signal, it still needs to be converted to 44.1 and 48khz internally using most likely a less then ideal chip set. otherwise not required when using the internal 44.1 clock directly. So while in theory using a reference should be better, they moved away from it.

I still would like to try it again and will look into some of the other choice you mention in your post. But, would it make any sense to any of you who experimented with this that the "conversion chip" that takes the 10Mhz to make it 44.1Khz inside the dCS clock may actually impact the desired result to the point using the internal being superior?

Are any of these reference clock you describe come with a linear power supply? I suspect why esoteric may have good result with their clock is because the Rodium reference is actually in the main Esoteric chassis, power by a linear power supply.

As you can see, many questions on this exciting subject!

Jacques

[custodian]

Jacques
Interesting post.

You are right, however DCS use conversion electronics for the inbuilt OCXO to generate the 44.1 and 48 signals.

The Antelope rubidium clock actually doesn't have particularly good phase noise which means it will not be major improvement when used as master clock for a DCS system. In simple terms, rubidium will have better long term stability but that has no real value in this application. There are techniques to link the rubidium source with an OXCO to produce an external master clock which improves on the basic DCS clock. I've done this on both Scarlatti and Vivaldi clocks with good results.

However at this level, a BVA OCXO gives much better results.

One other option I've not looked at would be to replace the OCXO in the Vivaldi with a performance optimised version of the same component. That might be worth looking at.

In the external master clock, psu and cabling are all of key importance in tweaking performance. Commercial problem with BVA remains the high cost of the crystal which means market very limited. Currently only available audiophile clock is $35k. I'm sure it could be produced at maybe $20k but even then, sales volume very limited.

[crwilli]

Am I the only one that has no idea what this thread is talking about? It's in English but reads like Greek to me. Where can I go to get 'clocking' for dummies? This thread is also an other reminder that there are whole other levels of this science and hobby which I am clueless to.

[JCR]

Am I the only one that has no idea what this thread is talking about? It's in English but reads like Greek to me. Where can I go to get 'clocking' for dummies? This thread is also an other reminder that there are whole other levels of this science and hobby which I am clueless to.

crwilli, no worries I am confused too about this topic sometime! One good place to learn about digital clock and how they are use/important in digital playback for DAC like the dCS ones, is actually on dCS website.

If you go on dCS website and read a bit on the dCS Vivaldi "stack" (aka clock+upsampler+DAC+ transport) they explain what each unit does and why they have a separate component for the clock - to synchronize all the digital equipment together. Think of it this way: no clock or bad clock = everything bad about digital sound; while good clock = a digital playback that could rival with analog playback...

Hope this helps...

[custodian]

Sorry. Didn't mean to complicate it.

I only got into this stuff when I had to scratch the urge to try the external master clock socket on the DCS system. It is inevitably a tricky subject. All I can say is that better short term accuracy = better sound.

Rubidium clocks don't necessarily improve sound because most of them don't improve short term accuracy.

Any of the external master clock options cost money so if you want to jump in, make sure you can try for a while first.

[JCR]

Jacques
Interesting post.

You are right, however DCS use conversion electronics for the inbuilt OCXO to generate the 44.1 and 48 signals.

The Antelope rubidium clock actually doesn't have particularly good phase noise which means it will not be major improvement when used as master clock for a DCS system. In simple terms, rubidium will have better long term stability but that has no real value in this application. There are techniques to link the rubidium source with an OXCO to produce an external master clock which improves on the basic DCS clock. I've done this on both Scarlatti and Vivaldi clocks with good results.

However at this level, a BVA OCXO gives much better results.

One other option I've not looked at would be to replace the OCXO in the Vivaldi with a performance optimised version of the same component. That might be worth looking at.

In the external master clock, psu and cabling are all of key importance in tweaking performance. Commercial problem with BVA remains the high cost of the crystal which means market very limited. Currently only available audiophile clock is $35k. I'm sure it could be produced at maybe $20k but even then, sales volume very limited.

A friend of mine has a recoding studio and I will ask him if he would know other brand of potential solution like you describe. Your comment about the Antelope would explain why I had mixed result with it. I kept scratching my head because logically I was so convinced there is a way to make the clock stock dCS clock sound better with a reference clock.

Would you be able or mind to expand what techniques/toold you use the improve on your Scarlatti and Vivaldi clock "link the rubidium source with an OXCO to produce an external master clock which improves on the basic DCS clock"?

How could one do that?

Jacques

[JCR]

Sorry. Didn't mean to complicate it.

I only got into this stuff when I had to scratch the urge to try the external master clock socket on the DCS system. It is inevitably a tricky subject. All I can say is that better short term accuracy = better sound.

Rubidium clocks don't necessarily improve sound because most of them don't improve short term accuracy.

Any of the external master clock options cost money so if you want to jump in, make sure you can try for a while first.

+1 ! I also only started to wonder after getting the dCS clock - but it is indeed a subject with very few folks having the experience for these things it would seems. I know when I started to ask about a reference clock to my dealer he was looking funny to me: what do you mean I just sold you a clock!

:scratch2:

[crwilli]

crwilli, no worries I am confused too about this topic sometime! One good place to learn about digital clock and how they are use/important in digital playback for DAC like the dCS ones, is actually on dCS website. If you go on dCS website and read a bit on the dCS Vivaldi "stack" (aka clock+upsampler+DAC+ transport) they explain what each unit does and why they have a separate component for the clock - to synchronize all the digital equipment together. Think of it this way: no clock or bad clock = everything bad about digital sound; while good clock = a digital playback that could rival with analog playback... Hope this helps...i will do that! Thank you.

Custodian - never apologize for bringing state of the art and beyond to AA. We all want to learn. Some just do it faster than others ;)

[custodian]

Having played with a few rubidium clocks and being confused with the results, I contacted a UK group which specialises in producing the highest accuracy timing devices for research. They were very kind and spent some time explaining the different options to me and they produced two prototype rubidium clocks with good short term stability. I thought they improved on the DCS clock. I did do a demo to the DCS sales director who was also enthusiastic about the results.

Sadly there is not much available "off the shelf" that I believe would really improve over the standard DCS clock. The Esoteric clock seems to have good performance although I haven't tried it. The Antelope is not, in my opinion, any improvement over the DCS internal clock. It sounds different but not better.

My view is that if you are going for an external master clock, go for a BVA. Expensive but really big improvement: it makes digital sound totally analog! As I posted previously, there is a Japanese company offering a commercial audiophile product but it is expensive. I got mine custom made using a standard Swiss made BVA crystal. A Scarlatti stack with a BVA master clock will comfortably outperform a Vivaldi stack using the DCS clock alone (in my opinion, for what that might be worth)

I have been trying to persuade the UK group to produce a commercial audio clock product but they are not convinced the market size justifies the effort which is a pity. The founder and owner of the UK group sadly died recently so there is some uncertainty over the future business direction. When things settle down, I'll revisit trying to encourage them to pitch an audio product.

[John49]

...I only got into this stuff when I had to scratch the urge to try the external master clock socket on the DCS system...

I have had a similar urge with my Marantz SA7-S1. Not dCS I know, but...

[custodian]

I have had a similar urge with my Marantz SA7-S1. Not dCS I know, but...

Try it. That's a very good unit so worth doing. Does the clock input take a standard 10mHz signal?

[JCR]

Custodian, I was able to find the BVA master clock you reference to. at $37k it is very expensive indeed but seem extremely well built! The same company seem to have a smaller model but not sure it is a BVA master clock. Anyway I will try to educate myself a bit more a this...

[custodian]

Custodian, I was able to find the BVA master clock you reference to. at $37k it is very expensive indeed but seem extremely well built! The same company seem to have a smaller model but not sure it is a BVA master clock. Anyway I will try to educate myself a bit more a this...

It does look very well constructed. That machined case reminded me of my Ayre KX-r preamp case. The Japanese distributor was helpful and offered to fly over to demonstrate the unit! It uses the same crystal as I have in mine. The component cost for the crystal is around $12k, so it is always going to be expensive. I think a commercial product could be $20k

[JCR]

Wow! They offered to fly for a demo! Then there is surely some room in their margin :-) So you have not found any other company doing this right? I will definitively try to learn more on this...

[custodian]

Wow! They offered to fly for a demo! Then there is surely some room in their margin :-) So you have not found any other company doing this right? I will definitively try to learn more on this... I couldn't find any other company offering a ready made product for audio use. It would not be too difficult to source the crystal and build such a device. The BVA used is made by Oscilloquartz in Neuchatel, Switzerland. Model number is BVA 8607. It has a 10x better short term accuracy than the best OCXO clock and is sold as a replacement for atomic clocks.

[JCR]

Humm...ok here is a stupid question! If it is sold as a replacement for atomic clock, could one buy a commercially available atomic clock (not sure if Antelope has one but I think they do) and then buy this BVA part number to replace the generator of the 10Mhz signal? This may be an oversimplification but just a thought!

Jacques

[custodian]

Humm...ok here is a stupid question! If it is sold as a replacement for atomic clock, could one buy a commercially available atomic clock (not sure if Antelope has one but I think they do) and then buy this BVA part number to replace the generator of the 10Mhz signal? This may be an oversimplification but just a thought! Jacques Not a simple straight replacement but could be possible. Although Antelope doesn't have special case or great power supply so would be much better to build new unit with custom case and high quality power supply. The lock electronics are not the same for a BVA clock so that would need changing if you tried to do a straight swaps

[JCR]

Not a simple straight replacement but could be possible. Although Antelope doesn't have special case or great power supply so would be much better to build new unit with custom case and high quality power supply. The lock electronics are not the same for a BVA clock so that would need changing if you tried to do a straight swaps

Ok thanks. I think I just found my next DIY project!

[John49]

Try it. That's a very good unit so worth doing. Does the clock input take a standard 10mHz signal?

From the manual, the frequency used is either 44.1, 88.2 or 176.4 kHz.

[custodian]

From the manual, the frequency used is either 44.1, 88.2 or 176.4 kHz.

Yes, that's the frequencies generated in the Marantz for different digital music signals. The external clock control is usually 10mhz. Is it not specified in the manual?

[crwilli]

Since I am learning fast (but still near the bottom of the curve) and have found myself in two threads on a new reclocking device from Wyred 4 sound and it seems these threads are largely about the same technology, how can there be a device that works at $399 and you are talking about devices where the parts cost $35,000?

It is mind blowing to me. I get there is a point of diminishing returns for almost everything and I celebrate those who won't accept being anywhere but at the pinnacle, but Geesh, what are the differences here?

Sent from my iPad using A.Aficionado

[Masterlu]

Since I am learning fast (but still near the bottom of the curve) and have found myself in two threads on a new reclocking device from Wyred 4 sound and it seems these threads are largely about the same technology, how can there be a device that works at $399 and you are talking about devices where the parts cost $35,000?

It is mind blowing to me. I get there is a point of diminishing returns for almost everything and I celebrate those who won't accept being anywhere but at the pinnacle, but Geesh, what are the differences here?

Sent from my iPad using A.Aficionado

Rubidium Clock:

Rubidium standard - Wikipedia, the free encyclopedia (http://en.m.wikipedia.org/wiki/Rubidium_standard)

Femto Clock:

Low Phase Noise Clock Synthesizers, Low Jitter Clocks - FemtoClock® | IDT (http://www.idt.com/products/clocks-timing/femtoclock-low-phase-noise-frequency-clock-synthesizers)

About Low-jitter Clocks
Jitter can be defined as the undesired deviation from an ideal periodic timing signal. Jitter may be observed in characteristics such as the frequency, phase, or amplitude of successive pulses. High levels of jitter can result in significant undesired system behavior in high-performance applications. IDT offers the industry's leading portfolio of low-jitter clock synthesizers and phase-locked oscillators (PLL oscillators) to meet the needs of virtually any application.

[custodian]

Since I am learning fast (but still near the bottom of the curve) and have found myself in two threads on a new reclocking device from Wyred 4 sound and it seems these threads are largely about the same technology, how can there be a device that works at $399 and you are talking about devices where the parts cost $35,000? It is mind blowing to me. I get there is a point of diminishing returns for almost everything and I celebrate those who won't accept being anywhere but at the pinnacle, but Geesh, what are the differences here? Sent from my iPad using A.Aficionado

Sorry, just not that simple.

Digital clocking is a complex subject with lots of different ways to do it, each with their benefits.

Devices used include crystals, rubidium sources, caesium decay sources, GPS clocks, hydrogen masers and others.

Some of these are incredible at long term timing so will be accurate to fractions of a second over a million years; others are good at keeping the time signal constant over very short intervals.

In audio, we are concerned about short term constancy.

Less expensive audio devices use an OTXO crystal; better equipment uses an OCXO crystal. Whilst OCXO devices are not hugely expensive, there is manufacturing variation in performance, so manufacturers of specialist equipment will often specify at the top end of the performance curve which adds greatly to manufacturing cost because of high scrap losses.

The OCXO crystal has very good short term performance, even compared to the more expensive devices above.

The external system clock used by DCS is an OCXO crystal.

To try to get better performance, people have tried rubidium clocks ( sometimes referred to as atomic clocks) which have better long term (drift) performance. These sre used in huge numbers in the telecoms industry and lots of cheap surplus devices packaged into a complete unit can be bought through surplus channels and eBay for around $100. The problem is that short term performance is generally poorer than a good OCXO crystal. Clever design and using rubidium and OCXO in the same device can give a clock with the best of both worlds.

Caesium, gps clocks, hydrogen masers etc are best ignored because of cost, complexity or performance issues.

A specialist rubidium clock for audio use can make a positive difference to sound quality. There are several on the market ranging from the Antelope device at below $5k up to the Esoteric clock. All will make the audio system sound different.

Finding the improvements from clock changes interesting, I talked with experts in digital timing in research applications and the recommendation for ultimate short term stability in a practical device was a very special variant of an OCXO crystal called a BVA in which a specially cut crystal is suspended in a complex structure and temperature stabilised in a double oven. The BVA based clock is typically 10x better than the best OCXO in the key parameters that effect use in audio systems. Problem is cost with the only available complete audio clock now being $37k.

People on audio forums have argued over the differences between analog and digital music reproduction for ever. All I can say is that in a good system, the BVA clock removes digital edge (presumably low level jitter) to a point that brings analog and digital much closer together.

I sound a bit like a missionary on this subject: I don't mean to become a preacher. I am not an expert in this field and the views above are grossly oversimplified and incomplete. Hopefully it has provided a useful overview of the options. I'm happy to demo the effects of my own BVA clock to anyone who happens to find themselves in this part of the UK

[cmarin]

Custodian,

Not preachy at all. Quite the contrary, thank you for explaining a complex subject so that even newbies such as myself can increase, even minimally, our understanding of a very complex subject.

As a friend of mine is fond if saying: "if you're not careful, you might just learn something".

Thanks again.

[chessman]

Custodian,

Not preachy at all. Quite the contrary, thank you for explaining a complex subject so that even newbies such as myself can increase, even minimally, our understanding of a very complex subject.

As a friend of mine is fond if saying: "if you're not careful, you might just learn something".

Thanks again.

+1! :)

[crwilli]

Custodian,

Not preachy at all. Quite the contrary, thank you for explaining a complex subject so that even newbies such as myself can increase, even minimally, our understanding of a very complex subject.

As a friend of mine is fond if saying: "if you're not careful, you might just learn something".

Thanks again.

EXACTLY! That is why I have no issue showing my ignorance on this topic. I assume there are others out there who may also benefit. HUGE fan of 'trickles down'.

[custodian]

Thanks Guys, glad it was useful. I feel like the teacher who is half a page ahead of the pupils. Problem is you now know as least as much as I do! I need to read some more so I can get ahead again

[JCR]

I sound a bit like a missionary on this subject: I don't mean to become a preacher. I am not an expert in this field and the views above are grossly oversimplified and incomplete. Hopefully it has provided a useful overview of the options. I'm happy to demo the effects of my own BVA clock to anyone who happens to find themselves in this part of the UK

Thanks for this clear explanation custodian! This is the clearest and best overview of the digital clock options/challenges I have seen and is quite useful! I will echo others here as not to worry about your "preaching"! We all need a little bit of that in this topic :yes:

I just wish that was more then a single $37k alternative out there :tears:

Thanks again for the clarity of your explanations!

Jacques

[wizard]

http://prohighend.ru/uploads/12/10/12/l_dCS_06_A.jpg

The OCXO clock used in dCS Puccini U-Clock.
It's from HCD Research, a UK company.

http://www.hcdresearch.co.uk/resources/images/shop-images/20120615090921-HCD331.pdf

[wizard]

Sorry, just not that simple.

Digital clocking is a complex subject with lots of different ways to do it, each with their benefits.

Devices used include crystals, rubidium sources, caesium decay sources, GPS clocks, hydrogen masers and others.

Some of these are incredible at long term timing so will be accurate to fractions of a second over a million years; others are good at keeping the time signal constant over very short intervals.

In audio, we are concerned about short term constancy.

Less expensive audio devices use an OTXO crystal; better equipment uses an OCXO crystal. Whilst OCXO devices are not hugely expensive, there is manufacturing variation in performance, so manufacturers of specialist equipment will often specify at the top end of the performance curve which adds greatly to manufacturing cost because of high scrap losses.

The OCXO crystal has very good short term performance, even compared to the more expensive devices above.

The external system clock used by DCS is an OCXO crystal.

To try to get better performance, people have tried rubidium clocks ( sometimes referred to as atomic clocks) which have better long term (drift) performance. These sre used in huge numbers in the telecoms industry and lots of cheap surplus devices packaged into a complete unit can be bought through surplus channels and eBay for around $100. The problem is that short term performance is generally poorer than a good OCXO crystal. Clever design and using rubidium and OCXO in the same device can give a clock with the best of both worlds.

Caesium, gps clocks, hydrogen masers etc are best ignored because of cost, complexity or performance issues.

A specialist rubidium clock for audio use can make a positive difference to sound quality. There are several on the market ranging from the Antelope device at below $5k up to the Esoteric clock. All will make the audio system sound different.

Finding the improvements from clock changes interesting, I talked with experts in digital timing in research applications and the recommendation for ultimate short term stability in a practical device was a very special variant of an OCXO crystal called a BVA in which a specially cut crystal is suspended in a complex structure and temperature stabilised in a double oven. The BVA based clock is typically 10x better than the best OCXO in the key parameters that effect use in audio systems. Problem is cost with the only available complete audio clock now being $37k.

People on audio forums have argued over the differences between analog and digital music reproduction for ever. All I can say is that in a good system, the BVA clock removes digital edge (presumably low level jitter) to a point that brings analog and digital much closer together.

I sound a bit like a missionary on this subject: I don't mean to become a preacher. I am not an expert in this field and the views above are grossly oversimplified and incomplete. Hopefully it has provided a useful overview of the options. I'm happy to demo the effects of my own BVA clock to anyone who happens to find themselves in this part of the UK

There's no OTXO clocks, but TCXO and yes they are cheaper than OCXO.

The $37000 Sforzato 01 with Oscilloquartz 8607 BVA is now $33000.

http://www.sfz.co.jp/PMC-03.jpg

http://en.sfz.co.jp/products/pmc/PMC-02-EX-inside.jpg

http://en.sfz.co.jp/products/pmc/PMC-02-EX_cristal.jpg

A cheaper model is PMC-03 at $2800. It uses a Oscilloquartz 8788.
Phase noise 1 Hz -100dB and 10 Hz - 130dB.

[custodian]

The OCXO clock used in dCS Puccini U-Clock. It's from HCD Research, a UK company. http://www.hcdresearch.co.uk/resources/images/shop-images/20120615090921-HCD331.pdf Yes. It is a standard product. The question is whether DCS have screened that product to select particularly good samples as there is likely to be sample to sample variance straight from the supplier of the standard device.

The cheaper PMC-03 device you list above is a standard OCXO. Oscilloquartz quote the 8607 as having a factor of 10 better stability.

I have no idea about the Sforzato pricing. Last quote they sent me was ¥3.8 million back in July. Maybe they were not overwhelmed with orders at that price.

Thanks for pointing out my error on TCXO : I need to proof read when I post on the run!

[custodian]

I do like the case construction in the Sforzato BVA clock: http://www.avcat.jp/main/avnews/files/2013/06/PMC-01top.jpg It would be interesting to try and machine a similar case from solid, maybe also keeping the psu in a seperate box. Next project!

[Mysound]

Hello, I run a DCS paganini transport and dac, and a scarlatti upsampler. I added an Antelope OCX/10Mhz combi, and it made a big difference, it whas like adjusting a binoculars, and the background became real black. I'm still looking for great clock-cables. Just my 50cnts

[JCR]

Hello, I run a DCS paganini transport and dac, and a scarlatti upsampler. I added an Antelope OCX/10Mhz combi, and it made a big difference, it whas like adjusting a binoculars, and the background became real black. I'm still looking for great clock-cables. Just my 50cnts

clock cable: I use the Siltech Golden Eagle 75 Ohm BNC digital cable for my dCS clock and it work really well. Extremely fluid cable. A major upgrade to anything I tried before.

I also had good result with using the Shunyata digital cable but they require you to use a RCA to BNC adapter since Shunyata does not offer BNC termination.

Jacques

[CGabriel]

clock cable: I use the Siltech Golden Eagle 75 Ohm BNC digital cable for my dCS clock and it work really well. Extremely fluid cable. A major upgrade to anything I tried before. I also had good result with using the Shunyata digital cable but they require you to use a RCA to BNC adapter since Shunyata does not offer BNC termination. Jacques

Just an FYI Jacques,

We are announcing a true 75 ohm BNC or RCA terminated cable specifically designed for clocks as used in dCS and Bel Canto and many others. This ANACONDA cable features our VTX (virtual tube geometry) with silver conductors and Teflon dielectrics. Official announcement and ship dates will be released next week.

BTW, dCS is currently using our 75 ohm COBRA cables for clock signals.

[custodian]

Hello, I run a DCS paganini transport and dac, and a scarlatti upsampler. I added an Antelope OCX/10Mhz combi, and it made a big difference, it whas like adjusting a binoculars, and the background became real black. I'm still looking for great clock-cables. Just my 50cnts

Now just imagine if you improved the clock accuracy by a factor of 10, how big of a further improvement you might get. That's what a BVA would do.

Sent from my iPad using A.Aficionado

[John49]

Yes, that's the frequencies generated in the Marantz for different digital music signals. The external clock control is usually 10mhz. Is it not specified in the manual?

No, it is not.

[JCR]

Just an FYI Jacques,

We are announcing a true 75 ohm BNC or RCA terminated cable specifically designed for clocks as used in dCS and Bel Canto and many others. This ANACONDA cable features our VTX (virtual tube geometry) with silver conductors and Teflon dielectrics. Official announcement and ship dates will be released next week.

BTW, dCS is currently using our 75 ohm COBRA cables for clock signals.

Caelin, this is a great news! Thanks for the update as I was not aware of that. I will for sure try the Anaconda version on my dCS. Now did I read this right and you mention that new BNC cable would be made with silver as opposed to copper? Very interesting.

I am also eagerly waiting for my local dealer shipment of your soon to be announced new line of power cords so I can try your new top of the line on my newly acquired MC2KW mono blocks!

Best,

Jacques

P.S.: I can't enough of your Typhon! I have 4 and could no longer live without them!

[custodian]

No, it is not.

Interesting.

I downloaded the manual and I understand now. On p21 it explains the external clock connection. It is designed to be used with an audio clock such as one of the DCS clocks which output the 44.1/48 frequency.

So you have two things to add:
First bypass the built in clock with an external clock outputting the selected frequency. Set the matching frequency on the Marantz.

Add a high resolution 10mhz clock to improve accuracy of the external clock.

Seems a bit of a nuisance if you are changing source to have to change frequency setting on two units.

[wizard]

The Quartzlock A10-M ULN rubidium frequency reference beats the Oscilloquartz 8607 used in Sforzato 01.

It's normally used to test quartz oscillators, and can be a reference to Quartzlock A-7 MXU Signal Stability Analyser. Phase noise on A-7 MXU is -130dB 1Hz and -115dB 0,1Hz.


A10-M ULN specs:

Phase noise - 1Hz -122dB, 10Hz - 137dB.
Aging - day 5x10-12, month 4x10-11 and year 4x10-10.

[CGabriel]

Caelin, this is a great news! Thanks for the update as I was not aware of that. I will for sure try the Anaconda version on my dCS. Now did I read this right and you mention that new BNC cable would be made with silver as opposed to copper? Very interesting. I am also eagerly waiting for my local dealer shipment of your soon to be announced new line of power cords so I can try your new top of the line on my newly acquired MC2KW mono blocks! Best, Jacques P.S.: I can't enough of your Typhon! I have 4 and could no longer live without them!

Yes, the Anaconda Digital cable AES/EBU and S/PDIF (BNC and RCA) cables will be made with a new conductor that we have developed. It uses very fine SPC wire in a VTX array. This geometry dramatically reduces skin effects at the high frequencies used in digital transmission.

This is a significant advance over our existing Anaconda Digital cable. We could have made a MKII version and raised the price of the cable but we have decided to contact all of our customers that have the older version Anaconda Digital cable. We are going to give existing owners a free exchange to the new cable. If you sent in your warranty card you will be contacted for an RMA.

We will start shipping the new cables next week. If you order a cable after next week you will get the new cable.

As for the SIGMA SERIES power cords, the first run will go into production next week barring any unforeseen hiccups.

As for the TYPHON's, It is being reviewed by one of the major magazines and should be out around the end of the year. watch for it.

[wizard]

The Quartzlock A10-M ULN rubidium frequency reference beats the Oscilloquartz 8607 used in Sforzato 01.

It's normally used to test quartz oscillators, and can be a reference to Quartzlock A-7 MXU Signal Stability Analyser. Phase noise on A-7 MXU is -130dB 1Hz and -115dB 0,1Hz.


A10-M ULN specs:

Phase noise - 1Hz -122dB, 10Hz - 137dB.
Aging - day 5x10-12, month 4x10-11 and year 4x10-10.

Oscilloquartz 8607 can be delivered with many options, but the price will also be higher.
Option L - phase noise -122dB 1Hz
Option J - daily aging - 3x10-12, but year aging will not be so good 1x10-9.

8607 very good for shorter uses, rubidium is better for longer uses.

Actually the longer one uses rubidium clocks the better the performance.
If its normally have for example 4x10-10 aging spec after 1 year, after 3 years of use now it have 4x10-13.


1x10-9 = 1 ppb - parts per billion
1x10-10 = 0,1 ppb
1x10-11 = 0,01 ppb
1x10-12 = 0,001 ppb - 1 pico second
1x10-13 = 0,0001 ppb
1x10-14 = 0,00001 ppb
1x10-15 = 0,000001 ppb - 1 femto second

[justubes]

The Quartzlock A10-M ULN rubidium frequency reference beats the Oscilloquartz 8607 used in Sforzato 01.

It's normally used to test quartz oscillators, and can be a reference to Quartzlock A-7 MXU Signal Stability Analyser. Phase noise on A-7 MXU is -130dB 1Hz and -115dB 0,1Hz.

A10-M ULN specs:

Phase noise - 1Hz 10Hz - 137dB.
Aging - day 5x10-12, month 4x10-11 and year 4x10-10.

Is the ULN a special order version?

The standard ones are already impressive at -110db at 1hz, -140db at 10hz. The stanford prs10 rubidium frequency used in the heart of the G01 is -105 at 1hz and -130hz at 10hz. Slightly less impressive specs.

The specs -130db 1 hz is approaching the 20x more costly BVA units. Thats mighty impressive for a special select version.


It might be better to focus on cables and PSU at this already insanely low levels than than just the lowest possible phase noise.

The Oscilloquartz units are used in dcs which are oven based clocks, their rubidiums phase noise are not as impressive in the low hz range comparatively

There is nothing on the pahse noise given for the esoteric G02. Can a selected grade ULN oven clock which can also approach the low phase noise in the low hz regions actually be comparable or better than some rubidium clocks and therefore sounding better?

The quartzlock A1000A consumer units, presumably also fitted with switching power supply is their offering as hifi consumer units, such as the antelope 10m and the stanford model perfection 10.

These are units which put out only a pure sine 10mhz frequency which does not go through a phase lock loop which further degrades the signal as in all hifi clocks units being offered. Is there a drawback about the esoteric G01 rubidium clock? It can output a 10m signal, it uses a 10 rubidium clock internally so why would it still have a clock input? Does running the signal through 2 rubidium clock sound better. What is this input for?

Stanford PRS10 -----> G01 ( also a same PRS10 clock inside) -------> cdp/transport/dac

Or as opposed to what is normally used, with great results already

G01 ----------> cdp/transport/dac



The problems is that many rubidium modules dont come with a better power supply also tend just to have an output impendence of 50 ohms instead of the usual 75ohms for consumer audio units being marketed.

50ohm is techinally better for transmitting mega hetz frequencies than 75ohm.

I wonder how large an impact this has sonically, hell, the traces in the boards and some connections dont even offer a true 75ohm impedence from the rubidium clocks output to the external bnc jack of these consumer units. Any experts opinion on how a true impedence of 50ohms or 75ohms can be obtained in the pcb boards connecting traces.

All these degrade or add jitter to the multi thousand dollar rubidium clock units. Could this impedence cause more jitter by using a external clock, but somehow with a better power supply and cables, makes the addition of an external atomic clock sound better only than just the cheap clock used inside the players/dacs/transport.

Any experts comments?

[wizard]

Esoteric G-02 uses a OCXO clock.

Phase noise is -95dB at 1Hz.
Accuracy is 0,01 ppm.

The Stanford PRS10 rubidium clock inside Esoteric G-01.
Phase noise is -103dB at 1Hz.

[custodian]

Esoteric G-02 uses a OCXO clock. Phase noise is -95dB at 1Hz. Accuracy is 0,01 ppm. The Stanford PRS10 rubidium clock inside Esoteric G-01. Phase noise is -103dB at 1Hz.

You are correct, however a BVA OCXO phase noise is -118dB at 1Hz.

[wizard]

You are correct, however a BVA OCXO phase noise is -118dB at 1Hz.

Yes I know the specs of 8607 already.

The OCXO clock used inside the €5400 Esoteric G-02 has a phase noise of -95dB at 1Hz.

http://www.esoteric.jp/products/esoteric/g02/img/photo03.jpg

http://www.esoteric.jp/products/esoteric/g02/img/photo02.jpg

[custodian]

Yes I know the specs of 8607 already. The OCXO clock used inside the €5400 Esoteric G-02 has a phase noise of -95dB at 1Hz.

I'm not really sure what your point is.

[justubes]

You are correct, however a BVA OCXO phase noise is -118dB at 1Hz.

Quartzlock E10 Y8

-110db at 1 hz, how would this compare to -118db at 1 hz?

But cost 10x less than a BVA with pretty impressive specs and beats all audiophile rubidium clocks currently in the market at a lower price too.

[custodian]

Quartzlock E10 Y8 -110db at 1 hz, how would this compare to -118db at 1 hz? But cost 10x less than a BVA with pretty impressive specs and beats all audiophile rubidium clocks currently in the market at a lower price too.


I do some work with Quartzlock and they supplied the components I used in my BVA including the Oscilloquartz BVA

The problem in answering your question is that we really don't know how big a sound difference is produced by changes in an already low phase noise. The decision to try a BVA approach was very much a "shot in the dark" and we were all surprised at the extent of the improvement over their OCXO and OCXO/rubididium products.

[JCR]

Yes, the Anaconda Digital cable AES/EBU and S/PDIF (BNC and RCA) cables will be made with a new conductor that we have developed. It uses very fine SPC wire in a VTX array. This geometry dramatically reduces skin effects at the high frequencies used in digital transmission.

This is a significant advance over our existing Anaconda Digital cable. We could have made a MKII version and raised the price of the cable but we have decided to contact all of our customers that have the older version Anaconda Digital cable. We are going to give existing owners a free exchange to the new cable. If you sent in your warranty card you will be contacted for an RMA.

We will start shipping the new cables next week. If you order a cable after next week you will get the new cable.

As for the SIGMA SERIES power cords, the first run will go into production next week barring any unforeseen hiccups.

As for the TYPHON's, It is being reviewed by one of the major magazines and should be out around the end of the year. watch for it.

Thanks for the update. I look forward to trying the new stuff and will make sure to give the new Anaconda digital cable a try in my system!

Best, Jacques

[justubes]

I do some work with Quartzlock and they supplied the components I used in my BVA including the Oscilloquartz BVA

The problem in answering your question is that we really don't know how big a sound difference is produced by changes in an already low phase noise. The decision to try a BVA approach was very much a "shot in the dark" and we were all surprised at the extent of the improvement over their OCXO and OCXO/rubididium products.


Could it be a case that the sum of all parts happened to be that very good lab specs (lowest phase noise at 1hz) alone may not be a determination of best sonic improvements.

An -8db is that significant to allow the BVA OCXO to sound hugely better? The improvement in sound as you described seems to be many times an improvement in the good rubidium counterparts.

In you testing, does the impedence, whether 50ohms or 75ohms cause any detriment to the sound is there are mismatched signal reflections. Most audiophile cable may not have a correct or accurate impedence. The cable choice can makes a significant positive difference to the sound.

So, could it be likewise apart from purely looking at phase noise, possible the BVA osc just sounds miles better. I have come across a review where a japanese forumer prefers to use the esoteric ocxo over the g0rb rubidium based clock, stating that the rubidium clock imparted a distinct sound and found the ocxo versiin more musical thou tje soynd not as detailed and clear as we put it in hifi terms.

[custodian]

Could it be a case that the sum of all parts happened to be that very good lab specs (lowest phase noise at 1hz) alone may not be a determination of best sonic improvements. An -8db is that significant to allow the BVA OCXO to sound hugely better? The improvement in sound as you described seems to be many times an improvement in the good rubidium counterparts. In you testing, does the impedence, whether 50ohms or 75ohms cause any detriment to the sound is there are mismatched signal reflections. Most audiophile cable may not have a correct or accurate impedence. The cable choice can makes a significant positive difference to the sound. So, could it be likewise apart from purely looking at phase noise, possible the BVA osc just sounds miles better. I have come across a review where a japanese forumer prefers to use the esoteric ocxo over the g0rb rubidium based clock, stating that the rubidium clock imparted a distinct sound and found the ocxo versiin more musical thou tje soynd not as detailed and clear as we put it in hifi terms.

I'm not sure what to add to my earlier comments.

The quoted figures for accuracy are several orders of magnitude better: phase noise improvements increase significantly across the frequency range also.

As I already said; all involved in listening tests were surprised at the magnitude of difference in sound quality.. Whether that was due to an 8dB phase noise difference:at 1kHz 32dB difference at 10kHz or a factor of 100 improvement in timing accuracy. To determine the relative contribution of each of these factors is way beyond what we set out to do.

Your point on cable termination impedance doesn't seem relevant, digital cables were identical during the testing. My preferred cables are Siltech signature cables but we also used MIT Oracle and Vertex hirez in setting up the system. An accurate assessment of termination reflections is way beyond what was essentially a subjective assessment.

Your mention of a single forum review by a Japanese former is not too surprising. As I said earlier, in the testing done at DCS using Quartzlock and other rubidium master clocks, some of us preferred the rubidium clock: others felt it was different but not necessarily better.

The BVA clock difference seemed to be much more specific in removing low level traces of digital glare whilst allowing more detail to come through.

It's important to remember what we were doing with this test. Having tried several rubidium clocks to see what improvements could be obtained in sound over the standard DCS clock, I decided to try the BVA which has the spec on paper that should be best in our application. The testing was to see if that translated into clear sound differences. The result was cleare than we expected. As a consequence I decided to spend some money to have the BVA as the reference clock in my system.

[justubes]

I'm not sure what to add to my earlier comments.

The quoted figures for accuracy are several orders of magnitude better: phase noise improvements increase significantly across the frequency range also.

As I already said; all involved in listening tests were surprised at the magnitude of difference in sound quality.. Whether that was due to an 8dB phase noise difference:at 1kHz 32dB difference at 10kHz or a factor of 100 improvement in timing accuracy. To determine the relative contribution of each of these factors is way beyond what we set out to do.

Your point on cable termination impedance doesn't seem relevant, digital cables were identical during the testing. My preferred cables are Siltech signature cables but we also used MIT Oracle and Vertex hirez in setting up the system. An accurate assessment of termination reflections is way beyond what was essentially a subjective assessment.

Your mention of a single forum review by a Japanese former is not too surprising. As I said earlier, in the testing done at DCS using Quartzlock and other rubidium master clocks, some of us preferred the rubidium clock: others felt it was different but not necessarily better.

The BVA clock difference seemed to be much more specific in removing low level traces of digital glare whilst allowing more detail to come through.

It's important to remember what we were doing with this test. Having tried several rubidium clocks to see what improvements could be obtained in sound over the standard DCS clock, I decided to try the BVA which has the spec on paper that should be best in our application. The testing was to see if that translated into clear sound differences. The result was cleare than we expected. As a consequence I decided to spend some money to have the BVA as the reference clock in my system.

Thanks for sharing your experience testing the wide number of clocks which none of us will ever have this oppurtunity to seed out the best.

Is uour unit being reference directly in your system or through a another device to output 44.1khz etc.

Of interest and some better direction on what the BVA can bring to a system, at your sessions at DCS, was it tested through the top end models, was any comparision made on using the BVA on the entry level system to guage the impact and whether the BVA will be a worthwhile improvement as opposed to spending first to upgrade components to the higher top level players before considering the BVA osc?

Was there a particular rubidium master ranked or that was preferred? Even in point that none compared to the BVA that can be recommended as a second best for the money or sonic differences head did not amount to a conclusive improvement by using any of the rubidium references?

I know it off topic from discussing BVA, but it' such a huge outlay for it's application for us audionuts.

[wizard]

http://www.abendrot.co.uk/images/slide/p01.jpg

Someone knows which type of Rubidium clock inside the $28000 Abendrot Stute?

STUTE | Abendrot (http://www.abendrot.co.uk/stute/)

[justubes]

Someone knows which type of Rubidium clock inside the $28000 Abendrot Stute?

STUTE | Abendrot (http://www.abendrot.co.uk/stute/)

It states a rubidium clock, if you were spending that money, best to follow custodian route and get a BVA clock.

If you dont need it in future, the BVA probably would be highly desired used for upgrading by some radar stations. It and a cesium reference would be top of the heap.

If the BVA module cost $15k, double that and nicely packaged to consumers at $30k in a nice case and power supply sound like a deal though hell lotta cash still.

[custodian]

DCS was only done using rubidium reference clock. BVA clock was built later.

I'm not sure which rubidium they preferred. In terms of standard product, the Stamford Research is pretty good.

Both rubidium and BVA are 10mHz so need the DCS clock to produce the audio clock.

10mHz is an industry standard, however in future projects, it would be better to tune the rubidium or.BVA to a number that is a multiple of 44.1 and 48 as this would simplify the processing algorithms.

[wizard]

I was reading a user test of Stute and Sforzato 01.

He and I've contacted Abendrot to get info on the clock, they won't tell about the clock used and the specs like phase noise. This could be some special technology or it could be a cheap clock they uses, so they only want to make money on it.

Dac was CH C1 with sync card - with Stute the sound was better, but the BVA inside just kills the Stute - actually no comparison, BVA at a different level.

[custodian]

I was reading a user test of Stute and Sforzato 01. He and I've contacted Abendrot to get info on the clock, they won't tell about the clock used and the specs like phase noise. This could be some special technology or it could be a cheap clock they uses, so they only want to make money on it. Dac was CH C1 with sync card - with Stute the sound was better, but the BVA inside just kills the Stute - actually no comparison, BVA at a different level.


SForzato use Oscilloquartz 8607 made in Switzerland. I use the same clock. 8607 phase noise and stability data is published on the Oscilloquartz website so no secret.

Since they have the only BVA clock available as a ready to use unit, they are able to price it at that level. However it should be possible to make an equivalent at around $20k.

[wizard]

Stute chassis is designed in Japan and uses a clock from UK.

Looking at the shipment accuracy, I think they uses a Quartzclock module inside.

[custodian]

Stute chassis is designed in Japan and uses a clock from UK. Looking at the shipment accuracy, I think they uses a Quartzclock module inside. I don't think its a Quarzlock rubidium module.


The 10-11 accuracy is typical for a good rubidium clock although of course accuracy over very short time period is more interesting. BVA will have at least 10-12 stability with better phase noise.

Do Stute actually charge $28k for that?

[Elberoth]

Humm...ok here is a stupid question! If it is sold as a replacement for atomic clock, could one buy a commercially available atomic clock (not sure if Antelope has one but I think they do) and then buy this BVA part number to replace the generator of the 10Mhz signal? This may be an oversimplification but just a thought!

Jacques

Apart from the PSU issues, the Rubidium module used in the Antelope 10M clock (Spectratime LCR-900) is PCB mountable, to allow seamless upgrade of OCXO crystal oscillators. The BVA clock would definately not fit plug & play.

[Elberoth]

BTW - for anyone interested in clock discussions, there is a great whitepaper on the Grimm Audio webpage on clocking, which I sugest everyone should read:

http://www.grimmaudio.com/site/assets/files/1088/picoseconds_or_ppm.pdf

It is written in a very simple language, and makes understanding clocking much easier.

[custodian]

BTW - for anyone interested in clock discussions, there is a great whitepaper on the Grimm Audio webpage on clocking, which I sugest everyone should read: http://www.grimmaudio.com/site/assets/files/1088/picoseconds_or_ppm.pdf It is written in a very simple language, and makes understanding clocking much easier. Not really. It's written as pseudo science but it's actually straight advertising for their CC1 clock.

Their section on jitter is laughable. They seem not have really understood what jitter is.

[Elberoth]

I beg to differ. I certainly didn't find anything laughable or inacurate in their whitepapers. I can assure you, that the guys at Grimm Audio know more about digital audio than all the people on this forum combined. And then multiplied by 10.

As for the 'advertising' part - they simply point out why Rubidium is not necessarely the Holy Grail in audio clocking and why a good (especially free running) OCXO can outperform it.

Which is exactly what you (and I) have been saying from the very begining ...

[custodian]

I beg to differ. I certainly didn't find anything laughable or inacurate in their whitepapers. I can assure you, that the guys at Grimm Audio know more about digital audio than all the people on this forum combined. And then multiplied by 10. As for the 'advertising' part - they simply point out why Rubidium is not necessarely the Holy Grail in audio clocking and why a good (especially free running) OCXO can outperform it. Which is exactly what you (and I) have been saying from the very begining ...

I don't think anything written so far on this thread makes any claim that rubidium fundamentally is better than OCXO. It has better long term stability but that is clearly hardly relevant.

In specific listening tests on specific equipment, differences were heard: the interpretation of those differences is open to debate. In my view, a good rubidium clock such as the SRS or Quarzlock had a positive impact on the sound from a clocked DCS Scarlatti or Vivaldi system in some specific tests. DCS feel that the differences are neither better nor worse; just different.

My notes on the BVA OCXO try to point out that the trial was done to see whether using an oscillator with a significantly better phase noise and stability would have a noticeable effect on sound quality. The conclusion was a resounding yes. It is tempting to extrapolate the results to conclude that very high short term stability is the road to removing the audible differences between the sound of analog and digital systems but I'll leave that to others. I'd ask you to re-read the short paragraph in the Grimm paper on jitter and then try to claim it makes any contribution to the understanding of jitter.

How do you reach the conclusion that the folks at Grimm Audio know more about digital audio than all the people on AA combined? Do you know enough about the sum of knowledge held by people on here? Sounds a bit of an outrageous claim without back up evidence.

[custodian]

Apart from the PSU issues, the Rubidium module used in the Antelope 10M clock (Spectratime LCR-900) is PCB mountable, to allow seamless upgrade of OCXO crystal oscillators. The BVA clock would definately not fit plug & play.

I thought we had covered this already in previous replies. It doesn't make a lot of sense to approach acquiring a BVA in that way. The BVA oscillator is the major cost element. The power supply requirements and lock signal provisions are different. The physical form and fit is different and finally, given the expense of the 8607, it would make sense to put it in a rather better non resonant enclosure than Antelope or similar use.

[justubes]

Custodian is stating his experiences of the BVA sounding better in the trials.

Industry users ina radar or guilded missile systems would crown this as tops, together with hydrogen and ceasium clocks. Cannot dispute these professionals as they know whats best!

Cost wise, even if i felt digging deep in to my pocket to spend on the BVA which i admit certainly am habouring these thoughs in the deepest regions of my heart. My brain cannot comprehend, short of being able to test one in my system which is impossible.

I am taking a more calculated approach in optimising sonically by way of cables and to be certain of achieviig what i expect as a great impovement to justifiy the expenditure. More importantly, to keep me busy and intrigued at least for the next 24 months playing with the clock, supplies and cables together allowing time to revisit my music with this setup.

This is gathered with my experience with the dcs clock, a good PC with a lesser digital clable didnt justify the aquisition, it was a sonic change more so than an outright improvement, it added what some have described akin to a magification through a better camera lens but musicality i felt was somehow subtracted. With a $3k digital cable,it now met my sonic expectations.

Correct me if inaccurate, the10m master clock to the dcs would still go through the dcs clock phase lock loops then to the transport/ dac, the esoteric on the otherhand, allows the 10m pure sine without any PLL. Could this be a superior implementation and use of the 10m to disclipline directly the espterics will accepts this connection? Im guessing it would, less is sometime best!

[Glisse]

A most interesting thread, and many thanks to Custodian for the primer on available clock technologies.

I think many of us that have been playing with different DACs for a while have recognised that those with very accurate clocks / low phase noise seems to sound more natural.

What seems to be happening now, as Custodian is highlighting, is that these variations seem to be relevant to what we hear, at amazingly tiny levels.

I have read conjecture that suggests that timing errors on digital create a completely unnatural sound, meant literally: a sound that does not occur in nature. As such, even at such tiny levels of difference, our brain discerns and is irritated by these errors. Who knows? There is no nexus between the engineering and biology departments in this field.

But my reason for intruding is that I have just read a comment by Michael Ritter, from Berkeley Audio Design, made in an interview featured in the latest issue of TAS, that addressed an area not yet discussed.

Implementation.

Ritter is adamant that having the clock any great distance from the digital to analogue conversion is a problem:

It’s a big effort to A, have a phenomenal clock and B, isolate it from
junk coming in and C, deliver it to where the payoff is at the DAC chip
in pristine form. I don’t understand those designs where the clock is
some distance from the converter, or worse, in a separate enclosure so
that the clock has to go through drivers, connectors, and cables. There’s
just no way that you can maintain the ultimate performance of a clock
when it goes through a long-distance transmission system like that. The
more advanced and extreme the clock’s performance, the more difficult
it is to maintain that performance at the DAC chip.

Of course, just one person's view, although he does have some form in this area.

[Mike1998]

I thought we had covered this already in previous replies. It doesn't make a lot of sense to approach acquiring a BVA in that way. The BVA oscillator is the major cost element. The power supply requirements and lock signal provisions are different. The physical form and fit is different and finally, given the expense of the 8607, it would make sense to put it in a rather better non resonant enclosure than Antelope or similar use.

Do you have pictures of your setup you can share?

[JCR]

Glisse, regarding the Berkeley interview, I have yet to audition a DAC without a seperate clock unit that sound as good as the systems with a seperate clock unit! So while his comments are not without merits, we should take them in the context that the Berkeley unit has its clock inside. Just my two cents. I have not eard the new Berkeley reference, but the previous generation was far from top of the line dCS or Esoteric performance...

[custodian]

Do you have pictures of your setup you can share?

Current BVA in use is in a standard Quarzlock enclosure damped with 2 Harmonic Resolution plates. Currently doing drawings to have a milled solid aluminium case.

[Glisse]

Glisse, regarding the Berkeley interview, I have yet to audition a DAC without a seperate clock unit that sound as good as the systems with a seperate clock unit! So while his comments are not without merits, we should take them in the context that the Berkeley unit has its clock inside. Just my two cents. I have not eard the new Berkeley reference, but the previous generation was far from top of the line dCS or Esoteric performance...

I don't think it is going to be easy to compare like with like: the same clock outside compared to the same clock within 2cm of the DAC.

Ritter could have put the clock wherever he wanted in their Reference model. He won't put USB conversion inside the DAC, and he won't allow the chip (which is Delta-Sigma) to do DSD conversion. So I doubt his comment on clock implementation is based on any marketing stuff. It does not seem the style of these Pacific Microsonics/BAD guys. They seem to be pure engineering.

[Elberoth]

I don't think anything written so far on this thread makes any claim that rubidium fundamentally is better than OCXO. It has better long term stability but that is clearly hardly relevant.


Correct. This is EXACTLY what Grimm's white paper says.

How do you reach the conclusion that the folks at Grimm Audio know more about digital audio than all the people on AA combined? Do you know enough about the sum of knowledge held by people on here? Sounds a bit of an outrageous claim without back up evidence.

Do you even know the guys behind the Grimm Audio ?

To quote their website:

Grimm Audio was founded by four of the Netherlands´ best known audio engineers: Bruno Putzeys, Guido Tent, Peter van Willenswaard and Eelco Grimm.

Those names may be unfamiliar to you, but Bruno Putzeys for example, is the engineering genius that stands behind the innovative N-Core switching amps (and Hypex before that). Their clocks and A/D converters are one of the most highly regarded in the pro industry.

Guido Tent, Peter van Willenswaard and Eelco Grimm do not fall far behind - they have also published numerous AES, IBC and SMPTE papers.

It is ironic, that you called their jitter section 'laughable', when Bruno Putzeys is the one who had actually published a AES paper on jitter (Effects of Jitter on AD/DA conversion. Specification of Clock Jitter Performance. 116th AES Convention, 2004).

http://www.grimmaudio.com/site/assets/files/1088/clock_jitter_spec-1.pdf

Do you have similar publications in your CV ?

I confess, I do not know all AA users and their background - that is simply not possible. But I'm frequent on this forum, and I haven't spoted a single member, whose understanding of digital audio could challenge the Grimm Audio guys.

[Elberoth]

Correct me if inaccurate, the10m master clock to the dcs would still go through the dcs clock phase lock loops then to the transport/ dac, the esoteric on the otherhand, allows the 10m pure sine without any PLL. Could this be a superior implementation and use of the 10m to disclipline directly the espterics will accepts this connection? Im guessing it would, less is sometime best!

The Esoteric DACs do accept 10M signal directly, but they still need an onboard PLL loop to generate the 44 and 48kHz freq families needed for the D/A conversion.

But it is true that Esoterics solution has one less digital cable and one PLL less, which - ceteris paribus - should lead to less jitter. But the dCS and Esoteric PLL designs are very different so it is difficoult to make any meaningful comparos.

Here it is how it looks in practice:

Esoteric:

Rubidium clock -> 10MHz signal -> PLL (in a DAC) -> 44.1/48kHz signals to D/A converter

dCS:
Rubidium clock -> 10MHz signal -> PLL (in a clock) -> 44.1/48kHz signals -> PLL (in a DAC) -> 44.1/48kHz signals to D/A converter

Esoteric solution would be even better, if they used two, top quality OCXO in the DAC itself. That would allow them to get rid of jitter inducing PLL and digital cable. That is what the GTE is doing in their Trinity DAC.

Trinity:

OCXO no.1 -> 44.1kHz signal to D/A converter
OCXO no.2 -> 48kHz signal to D/A converter

Same box, no PLL, no clock cables, just a superior clock a few cm from the DAC chipset.

[Elberoth]

It’s a big effort to A, have a phenomenal clock and B, isolate it from
junk coming in and C, deliver it to where the payoff is at the DAC chip
in pristine form. I don’t understand those designs where the clock is
some distance from the converter, or worse, in a separate enclosure so
that the clock has to go through drivers, connectors, and cables. There’s
just no way that you can maintain the ultimate performance of a clock
when it goes through a long-distance transmission system like that. The
more advanced and extreme the clock’s performance, the more difficult
it is to maintain that performance at the DAC chip.

What Ritter have said is very true. You have to realise, then even if you have the very best clock (in another box) that would do say -130dB @ 1Hz, after passing the fragile clock signal through numerous cables, connectors, drivers and PLL loops, the signal that reaches the DAC chipset will never have the same performance. It will be seriously degraded, as every cable and every PLL adds jitter (increases the phase noise).

This is why it is sometimes better to use a slightly worse performing clock (but still top quality), say measuring -100dB @ 1Hz, but very close to the DAC chipset, with no PLL, than the super-duper clock in a separate box.

Needless to say, that option is only available to DAC designers. If you are a dCS (or Esoteric) user, you can only play with various clock models (Rubidium and OCXO; stand alone and on top of your exisiting clock), like custodian did.

[custodian]

Correct. This is EXACTLY what Grimm's white paper says. Do you even know the guys behind the Grimm Audio ? To quote their website: Grimm Audio was founded by four of the Netherlands´ best known audio engineers: Bruno Putzeys, Guido Tent, Peter van Willenswaard and Eelco Grimm. Those names may be unfamiliar to you, but Bruno Putzeys for example, is the engineering genius that stands behind the innovative N-Core switching amps (and Hypex before that). Their clocks and A/D converters are one of the most highly regarded in the pro industry. Guido Tent, Peter van Willenswaard and Eelco Grimm do not fall far behind - they have also published numerous AES, IBC and SMPTE papers. It is ironic, that you called their jitter section 'laughable', when Bruno Putzeys is the one who had actually published a AES paper on jitter (Effects of Jitter on AD/DA conversion. Specification of Clock Jitter Performance. 116th AES Convention, 2004). http://www.grimmaudio.com/site/assets/files/1088/clock_jitter_spec-1.pdf Do you have similar publications in your CV ? I confess, I do not know all AA users and their background - that is simply not possible. But I'm frequent on this forum, and I haven't spoted a single member, whose understanding of digital audio could challenge the Grimm Audio guys.

Well if you accept digital audio is about digital data transmission, I have my name on several patents in that space as well as owning (and in two cases) founding several companies in that area. Our core activities relate to data integrity in covert and difficult areas so there is some expertise there. I spent some time working with the Defence Evaluation Research Agency (now QinetiQ) which happens to be the place where radar was invented and one of my Boston based companies is very active in current military projects in this space. More recently I have been looking in detail at audio applications for some of these technologies; this includes advising the people at Quarzlock on the audio applications for their clock technology.

My education was to PhD in a related area and my CV includes providing expertise to several well know research institutions in the US, UK and Russia.

Now I am one fairly junior member on here. I can't comment on the. Total experience of the rest of the membership!

I had not really wanted to enter a pissing contest on this but you really left me little choice. On that note, I'll leave this thread to others as I just want to get on enjoying the sound that I'm getting with the BVA clock.

[Glisse]

What Ritter have said is very true. You have to realise, then even if you have the very best clock (in another box) that would do say -130dB @ 1Hz, after passing the fragile clock signal through numerous cables, connectors, drivers and PLL loops, the signal that reaches the DAC chipset will never have the same performance. It will be seriously degraded, as every cable and every PLL adds jitter (increases the phase noise).

This is why it is sometimes better to use a slightly worse performing clock (but still top quality), say measuring -100dB @ 1Hz, but very close to the DAC chipset, with no PLL, than the super-duper clock in a separate box.

Needless to say, that option is only available to DAC designers. If you a dCS (or Esoteric) user, you can only play with various clock models (Rubidium and OCXO; stand alone and on to of your exisiting clock), like custodian did.

For sure.

One of the other interesting, and pertinent to this thread, comments that Ritter made is that they have reached the limit of current phase noise analysers where the best clocks are below the measurement threshold. As I don't know how their new clock measures, not sure what this threshold is.

[custodian]

I'd love to have someone explain the Grim explanation of jitter to me.

[custodian]

Quote from the Abendrot website on the $28k clock:

"The fundamental product of Abendrot Audio, a rubidium master clock placed in a beautiful aluminium cabinet, finally came to completion. STUTE is a master clock of supremacy designed for high-end digital audio system as well as a fruition of state-of-the-art technology of space development. Having the potentiality only can be actualized by a unique adjustment circuit, this rubidium oscilator with accuracy of 1 second in 1,000 years enables floating satellites to travel through several light years correctly. STUTE by Abendrot Audio, designed by the few existing professionals well versed in this secret technology, is the only genuine rubidium master clock. It is an ultimate collection for your audio system as well as an invitation to the deep, profound universe of sound."

Who writes such garbage?

[Glisse]

Well if you accept digital audio is about digital data transmission, ...

I had not really wanted to enter a pissing contest on this but you really left me little choice. On that note, I'll leave this thread to others as I just want to get on enjoying the sound that I'm getting with the BVA clock.

That would be a shame, as your thread subject and experiments have been interesting. And very pertinent to the evolution of digital replay.

The problems of internet communication!! Both you and Adam are right re. Grimm, just disagreeing on details, focus and perceived intent :D

I hope you reconsider.

[justubes]

We audiophools are all cool, in our own funny ways.

It is the desire and quest for knowledge that we share our ideas and experiences.


This guy is cool, definately ahead of any of our so call "high end" high priced digital systems.

Do a google translate. Now this is for the love of the hobby but Grimm is no where close, nor is dcs, nor esoteric ......

BVA clock are super exotic for most audiophiles which draws some blows, its all for commercial gain at the prices we pay to audio manufacturers.

Is there a better mousetrap, a better idea? This guy has done it, no side taken for dcs or esoteric or solution etc....


Search "Philips CDpro2LF top turntable built Rubidium" google is the best!
Its a first Rubidium clock in the cd player!

Custodian has done his BVA at oem costs and shares his findings, excellent job and think is a great deal .! I researched rubidium clock to the nines. Well, i was about to spring for a G01 but heck, let have some fun.

Esoteric aluminium casing cost to oem $800
Prs10 say $2,000
Transformers $200
Pcb, vcxo, misc parts etc $1,000

R&D - not much in designing a rubidium clock

Sfz clock at $35,000 is surely underpriced especially at the volumes they move.

Wow... solves all contest!

[justubes]

Some interesting extracts on this topic , note translated by google

Smartphone version is here.DDS method rubidium word clock generator　History of development
since it is not in the relationship of an integral multiple and 10MHz reference being used and measurement instruments, in order to obtain a signal of an integral multiple another oscillator frequency that is used in audio and (VCO / VCXO) He is trying to to be locked to the reference using. This method is effective in the case of obtaining a (22.5792MHz needed by the DAC inside, for example) frequency of 10MHz or more, but largely depends on the oscillator short-term frequency stability and phase noise (in the range of tau = 0.01sec-100sec about) will. Currently, these oscillators is so far short of the performance of the OCXO of 10MHz. You clearly inferior as compared to the reference of 10MHz (Although they may have been expressed as the neighborhood noise) phase noise of low-offset region in particular. There is little or no effect on the signal phase noise of the reference of 10MHz is output even how well So. It is a good idea from someone's standpoint measuring the phase noise of the direct master clock 22.5792MHz enter the 10MHz of high-performance OCXO rubidium or GPS to word clock in excess of one million yen To confirm this truth. It is probably that noticed already, to frequency conversion without deteriorating the characteristics of the reference (property), it means system which does not interposed another oscillator is good. It is are you realize this is the DDS (Direct Digital Synthesis). Nice contrast, in the so-called down-conversion of about 40% of the frequency that you input is the upper limit when using the DDS, it is common to use at around 20% in order to secure the signal quality. Therefore, the frequency of about 100MHz is required if you want to output the 22.5792MHz that are used to direct the master clock. Circuit for multiplying the frequency that you enter has a built-in DDS for this, but it does not work in the case of many less than 25MHz. Multiplier is required separately when you use the reference of 10MHz. For example, it seems that using by multiplying the 10MHz reference of arbitrary waveform oscillator of the DDS system of commercially available phase noise obtained when the output 22.5792MHz has deteriorated considerably. To configure the multiplier of low phase noise and does not seem to be easy. It follows that there is only used to direct the oscillation it becomes that it is not can also use the multiplier, but better to use the atomic clock, such as rubidium is advantageous if you get a reference to a higher frequency. OCXO will be difficult to secure the short-term frequency stability frequency is higher that the best performance of 5MHz is known. You are using a VCXO order to lock in the atomic clock Rujiumu was also division of course, but you can be kept relatively good frequency stability and phase noise VCXO that is built into the rubidium oscillator can be narrow lock range . It is a matter of comparison only, but it can be said that the latter is clearly better signal obtained using the rubidium and the signal was 20/10 multiplying the 5 / 10MHz is (100MHz). If the conclusion, we compared 22,5792MHz obtained in the DDS is allowed to lock to the 100MHz of rubidium 22.5792MHZ obtained by locking the 10MHz the VCXO, if this latter is better apparently claims us right It will be had, but the result of the measurement of short-term frequency stability and phase noise, DDS scheme had better it is not to say. master clock of the DDS system which we have made, we realized by frequency 22.5792MHz more than double the short-term frequency stability and phase noise of equal to or greater than the 10MHz that output in a high performance rubidium FE5680A. DDS system I think that it has excellent characteristics to convert the frequency of the audio without degrading the properties of the (rubidium) and oscillation has available

[custodian]

Some interesting extracts on this topic , note translated by google Smartphone version is here.DDS method rubidium word clock generator　History of development since it is not in the relationship of an integral multiple and 10MHz reference being used and measurement instruments, in order to obtain a signal of an integral multiple another oscillator frequency that is used in audio and (VCO / VCXO) He is trying to to be locked to the reference using. This method is effective in the case of obtaining a (22.5792MHz needed by the DAC inside, for example) frequency of 10MHz or more, but largely depends on the oscillator short-term frequency stability and phase noise (in the range of tau = 0.01sec-100sec about) will. Currently, these oscillators is so far short of the performance of the OCXO of 10MHz. You clearly inferior as compared to the reference of 10MHz (Although they may have been expressed as the neighborhood noise) phase noise of low-offset region in particular. There is little or no effect on the signal phase noise of the reference of 10MHz is output even how well So. It is a good idea from someone's standpoint measuring the phase noise of the direct master clock 22.5792MHz enter the 10MHz of high-performance OCXO rubidium or GPS to word clock in excess of one million yen To confirm this truth. It is probably that noticed already, to frequency conversion without deteriorating the characteristics of the reference (property), it means system which does not interposed another oscillator is good. It is are you realize this is the DDS (Direct Digital Synthesis). Nice contrast, in the so-called down-conversion of about 40% of the frequency that you input is the upper limit when using the DDS, it is common to use at around 20% in order to secure the signal quality. Therefore, the frequency of about 100MHz is required if you want to output the 22.5792MHz that are used to direct the master clock. Circuit for multiplying the frequency that you enter has a built-in DDS for this, but it does not work in the case of many less than 25MHz. Multiplier is required separately when you use the reference of 10MHz. For example, it seems that using by multiplying the 10MHz reference of arbitrary waveform oscillator of the DDS system of commercially available phase noise obtained when the output 22.5792MHz has deteriorated considerably. To configure the multiplier of low phase noise and does not seem to be easy. It follows that there is only used to direct the oscillation it becomes that it is not can also use the multiplier, but better to use the atomic clock, such as rubidium is advantageous if you get a reference to a higher frequency. OCXO will be difficult to secure the short-term frequency stability frequency is higher that the best performance of 5MHz is known. You are using a VCXO order to lock in the atomic clock Rujiumu was also division of course, but you can be kept relatively good frequency stability and phase noise VCXO that is built into the rubidium oscillator can be narrow lock range . It is a matter of comparison only, but it can be said that the latter is clearly better signal obtained using the rubidium and the signal was 20/10 multiplying the 5 / 10MHz is (100MHz). If the conclusion, we compared 22,5792MHz obtained in the DDS is allowed to lock to the 100MHz of rubidium 22.5792MHZ obtained by locking the 10MHz the VCXO, if this latter is better apparently claims us right It will be had, but the result of the measurement of short-term frequency stability and phase noise, DDS scheme had better it is not to say. master clock of the DDS system which we have made, we realized by frequency 22.5792MHz more than double the short-term frequency stability and phase noise of equal to or greater than the 10MHz that output in a high performance rubidium FE5680A. DDS system I think that it has excellent characteristics to convert the frequency of the audio without degrading the properties of the (rubidium) and oscillation has available

I've lost the will to live. Pass the kerosene.

[wizard]

Quote from the Abendrot website on the $28k clock:

"The fundamental product of Abendrot Audio, a rubidium master clock placed in a beautiful aluminium cabinet, finally came to completion. STUTE is a master clock of supremacy designed for high-end digital audio system as well as a fruition of state-of-the-art technology of space development. Having the potentiality only can be actualized by a unique adjustment circuit, this rubidium oscilator with accuracy of 1 second in 1,000 years enables floating satellites to travel through several light years correctly. STUTE by Abendrot Audio, designed by the few existing professionals well versed in this secret technology, is the only genuine rubidium master clock. It is an ultimate collection for your audio system as well as an invitation to the deep, profound universe of sound."

Who writes such garbage?

When I asked them about phase noise and other specs on it - no answer.

They think because we are using a nice chassis and a high price, people think we are using the best clock available inside. The no specs thing - reminds me of Goldmund before.
Something fishy about the clock inside? I think it's a cheap clock they are using.

Sforzato BVA at $33000 is cheap vs the $28000 Stute.
BVA performance is at a different level.

[custodian]

When I asked them about phase noise and other specs on it - no answer. They think because we are using a nice chassis and a high price, people think we are using the best clock available inside. The no specs thing - reminds me of Goldmund before. Something fishy about the clock inside? I think it's a cheap clock they are using. Sforzato BVA at $33000 is cheap vs the $28000 Stute. BVA performance is at a different level.

The Stute spiel reminds me of a dodgy art dealer. That sort of rubbish does the industry no good at all and at a price of $28k, it really is ridiculous.

[Elberoth]

Well, i was about to spring for a G01 but heck, let have some fun.

Esoteric aluminium casing cost to oem $800
Prs10 say $2,000
Transformers $200
Pcb, vcxo, misc parts etc $1,000

R&D - not much in designing a rubidium clock

Sfz clock at $35,000 is surely underpriced especially at the volumes they move.

Wow... solves all contest!

I'm pretty sure the real numbers are quite different (casing costs much more; PRS-10, transformers & misc parts - less), but I would be surprised if the total BOM would be more than $4000. Which would be in line with othere hi-end products, where BOM mostly accounts for 20% of the retail price.

If the rubidium module used in the Sforzato Clock indeed costs $12k in retail alone, then $32k retail price would be more than justified on BOM basis.

[custodian]

That would be a shame, as your thread subject and experiments have been interesting. And very pertinent to the evolution of digital replay. The problems of internet communication!! Both you and Adam are right re. Grimm, just disagreeing on details, focus and perceived intent :D I hope you reconsider.

Thanks for your encouragement.

Early on in the thread, I'd got across the information that there was evidence of major sound quality improvements by pursuing clock technology. I think the take up of that clock technology in audio will be very limited at the current Sforzato pricing. In refining my own unit, it is possible that a small run of BVA clocks could be produced at a more reasonable price but that is no more than an idea at present.

I'll update the thread if and when I make any progress on this.

[custodian]

I'm pretty sure the real numbers are quite different (casing costs much more; PRS-10, transformers & misc parts - less), but I would be surprised if the total BOM would be more than $4000. Which would be in line with othere hi-end products, where BOM mostly accounts for 20% of the retail price. If the rubidium module used in the Sforzato Clock indeed costs $12k in retail alone, then $32k retail price would be more than justified on BOM basis.

The Sforzato unit does not use a rubidium module. Are you getting confused with the Stute!

Pricing for a BVA oscillator module alone is very high. Depends of course on quantity and exact spec but could certainly much higher than the commercial rubidium modules. For real prices, contact Oscilloquartz in Lausanne and get a quote for BVA 8607.

[custodian]

To help clarify any misunderstanding on this BVA thing I keep banging on about, let me add a bit of background.

"Several resonator configurations are possible, in addition to the classical way of directly attaching leads to the crystal. E.g. the BVA resonator (Boîtier à Vieillissement Amélioré, Enclosure with Improved Aging),developed in 1976; the parts that influence the vibrations are machined from a single crystal (which reduces the mounting stress), and the electrodes are deposited not on the resonator itself but on the inner sides of two condenser discs made of adjacent slices of the quartz from the same bar, forming a three-layer sandwich with no stress between the electrodes and the vibrating element. The gap between the electrodes and the resonator act as two small series capacitors, making the crystal less sensitive to circuit influences.The architecture eliminates the effects of the surface contacts between the electrodes, the constraints in the mounting connections, and the issues related to ion migration from the electrodes into the lattice of the vibrating element.The resulting configuration is rugged, resistant to shock and vibration, resistant to acceleration and ionizing radiation, and has improved aging characteristics. AT cut is usually used, though SC cut variants exist as well. BVA resonators are often used in spacecraft applications."

So in summary, this is an alternative structure for an OCXO oscillator which is designed to improve both performance and reliability but at the cost of much more complex and expensive production.

[Elberoth]

The Sforzato unit does not use a rubidium module. Are you getting confused with the Stute!

Pricing for a BVA oscillator module alone is very high. Depends of course on quantity and exact spec but could certainly much higher than the commercial rubidium modules. For real prices, contact Oscilloquartz in Lausanne and get a quote for BVA 8607.

You are correct. What I meant is the BVA 8607, which is not a rubidium oscilator. I think I read somwhere in this thread it costs $12k in OEM.

[custodian]

You are correct. What I meant is the BVA 8607, which is not a rubidium oscilator. I think I read somwhere in this thread it costs $12k in OEM. Yes, I've seen similar pricing but with such OEM production, pricing varies quite a lot between customers and volumes. Maybe I should make a price enquiry on Oscilloquartz.

They also get a spread of performance because of the complexity of the manufacturing process. The top of the quality curve are the "08" variant which sell at a large premium. Total production of this variant is around 12 per year.

[custodian]

I found a quotation for a one off 8607 at 34040 SFR!

That really is a scary price but can be bought for much less by OEM customers.

Also found short term stability comparison with $300k hydrogen maser and the 8607 was better.

[Glisse]

I think Oscilloquartz only deal with large OEM, but they do seem to have quite a few resellers. Why don't you ask them which reseller can provide the 8607?

When I was looking at them, I see also that they did develop prototypes of an 8607-C, with a target of -160dBc/1Hz. They seemed to hit -134dB. This was 2007, never went into production.

http://hal.archives-ouvertes.fr/docs/00/28/05/39/PDF/2007_3_EFTF_2007_Mes_res_OSA_ifcf07.pdf

[custodian]

I think Oscilloquartz only deal with large OEM, but they do seem to have quite a few resellers. Why don't you ask them which reseller can provide the 8607? When I was looking at them, I see also that they did develop prototypes of an 8607-C, with a target of -160dBc/1Hz. They seemed to hit -134dB. This was 2007, never went into production. http://hal.archives-ouvertes.fr/docs/00/28/05/39/PDF/2007_3_EFTF_2007_Mes_res_OSA_ifcf07.pdf

You are correct. That's how I bought mine.

The current higher performance variant is the -08 model which is actually just selected from the top tested samples of the standard product. That performance grading is normal in this industry

[wizard]

http://cybwiz.zenfolio.com/img/s7/v155/p105241148-3.jpg

8607 BVA have a 50 ohm impedance with SMA connectors on it.
On the Sforzato 01 they have converted them to 50 ohm BNC.

But what about the 25 ohm impedance difference between BVA and 75 ohm BNC connector on dCS Vivaldi Master Clock and CH C1 sync card, can this difference be heard?

I see that dCS Vivaldi Master Clock accepts 1, 5 and 10 MHz on the ref input.
And 8607 BVA 5 MHz version phase noise spec is -125 dB ( Option L -130 dB).

5 MHz sounds better than 10 MHz?

[wizard]

http://www.pasternack.com/images/Product/large/PE7006.jpg

Anyone tried this 50 ohm to 75 ohm impedance transformer from Pasternack?


Pasternack matching pads (aka resistive impedance transformers or minimum loss pads) are passive coaxial components that allow impedance matching between 50 Ohm and 75 Ohm systems without introducing a lot of reflection to the circuit. Matching pads from Pasternack are ideal for applications requiring a connection between a 50 Ohm cable and 75 Ohm system.

[justubes]

http://www.pasternack.com/images/Product/large/PE7006.jpg

Anyone tried this 50 ohm to 75 ohm impedance transformer from Pasternack?


Pasternack matching pads (aka resistive impedance transformers or minimum loss pads) are passive coaxial components that allow impedance matching between 50 Ohm and 75 Ohm systems without introducing a lot of reflection to the circuit. Matching pads from Pasternack are ideal for applications requiring a connection between a 50 Ohm cable and 75 Ohm system.


This pads causes loses of a few db,at at 0.5v direct fro the 10m osc output, it can have problems with the signal becoming too low for a good lock. Any one knows?

[custodian]

8607 BVA have a 50 ohm impedance with SMA connectors on it. On the Sforzato 01 they have converted them to 50 ohm BNC. But what about the 25 ohm impedance difference between BVA and 75 ohm BNC connector on dCS Vivaldi Master Clock and CH C1 sync card, can this difference be heard? I see that dCS Vivaldi Master Clock accepts 1, 5 and 10 MHz on the ref input. And 8607 BVA 5 MHz version phase noise spec is -125 dB ( Option L -130 dB). 5 MHz sounds better than 10 MHz? It would be much better if the Vivaldi could accept higher frequency band, say 10-15mHz.

[wizard]

http://www.gvnweb.nl/BNC_75vs50.jpg

50 ohm looks like not so good on digital, I've seen it used by darTzeel so it works very good on analog.

http://www.fairviewmicrowave.com/images/Product/large/SI1560.jpg

One can use a SMA to 75 ohm BNC adapter - connect it directly to the BVA.

[custodian]

50 ohm not so good on digital, I've seen it used by darTzeel so it works very good on analog. One can use a SMA to 75 ohm BNC adapter - connect it directly to the BVA. What's you evidence for the 50ohm connector being a problem? All the rubidium modules I've looked at use that connector so always used with adaptor. In the audiophile products, the rear panel 75ohm BNC is connected via adaptor to the 50ohm internal rubidium module. I've also seen the 9pin connector on the rubidium clock wired directly to 75 ohm BNC but no great audible difference.

[wizard]

What's you evidence for the 50ohm connector being a problem? All the rubidium modules I've looked at use that connector so always used with adaptor. In the audiophile products, the rear panel 75ohm BNC is connected via adaptor to the 50ohm internal rubidium module. I've also seen the 9pin connector on the rubidium clock wired directly to 75 ohm BNC but no great audible difference.

Found it on Wikipedia, no problem up to 10 MHz, only above it.

"At frequencies below 10 MHz the impedance mismatch between a 50 ohm BNC connector or cable and a 75 ohm one has negligible effects. BNC connectors were thus originally made only in 50 ohm versions, for use with any impedance of cable. Above this frequency, however, the mismatch becomes progressively more significant and can lead to signal reflections."

[custodian]

One thing to watch in the 10mHz cable is to avoid external vibrations. Moving the cable will affect the signal. I've seen demonstrations of this at CERN looking in detail at signal effects. More important than worrying about 50ohm connectors is looking at ways to isolate the cable from audio frequency vibrational energy.

[custodian]

I received the following e-mail this morning from Sforzato's distributors:

"Regarding the PMC-00 BVA EX, the Occilloquarza 8607 unit will be end of
life of production.
The last order of the unit is Dec 15 this year.
If you really interested in the PMC-00 BVA EX, please order by the end of October."

Better get your cheque books out, guys!

[Glisse]

As Oscilloquartz use the 8607 module in quite a few of their product line, you would think there may be a replacement?

Then again, maybe not.

From what I gleaned reading annual reports, they had been losing money for the last few years, and there was a sense the SWATCH group had been putting the screws on their R&D budget. Now they have sold them to ADVA, the focus may be more on networking applications. I don't know enough about this industry to understand whether the short-term accuracy of the BVA OCXO is more or less important than the long term accuracy of the other clocking devices they make?

But based on the excellent post you made earlier describing the different clocking technologies, and where you referenced the network industry, it seems the short term accuracy and low phase noise of the BVA is not required for network transmission. Bye Bye BVA ?? :tears:

BTW, I did read on a strange bulletin board called Time-Nuts, or similar, that Oscilloscope had implied the OEM price of a 8607 was less than USD6,000. This was in response to a query made to them by someone who was considering a previous model BVA that was going on eBay for USD4,500. Oscilloscope said that price was way too high, and only a little under the new price for an 8607.

Of course, putting an OEM part inside a case with power supply, connectors, labour, overheads etc, probably means a $7k cost, a $10k wholesale to distributor, a $15k to retailer, then a $23k retail price, etc. As you and others have surmised.

[custodian]

Yes, agreed.

I've sent a quotation request to Oscilloquartz for 1 off and 10 off 8607 as well as for selected higher spec variants from one of my US companies that is a credible OEM purchaser so I'll let you know what I get back

[justubes]

Is the bva8607 now priced better for a end of production life osc?

Any updates on this?

[TLi]

I have heard it is possible to link the clock with GPS signal using an antenna. Has anyone tried that before? The GPS clock should be top grade.

[justubes]

If using a OSC like the PRS10 or better like the BVA, dont think there are any GPS references that can give you any better accuracy and phase noise than using these units by using an external reference.

There are many cheaper rubidium osc's that may benefit provided they have a input allowing a more accurate reference.

[custodian]

I have heard it is possible to link the clock with GPS signal using an antenna. Has anyone tried that before? The GPS clock should be top grade.

The GPS clock has great long term stability but poor short term stability so not really useful for digital audio.

I have used GPS clock to provide long term reference but had no benefit.

[TLi]

Has anyone tried to use different clock frequencies?

It is mentioned in dCS manual that we can use the multiples of 44.1 and 48 Hz to lock on other equipment. What effect does it have on the sound?

[jfrech]

Hi I have to some extent...on a few SACD's. Seems to add "air"...but I decided I liked the base frequencies the best so far. John Quick from dCS says the filters are optimised for the 44.1 or 48 frequency and that might have something to do with it. I am also guessing over time dCS may continue to tweak the filtering on the higher clock frequencies...but just a sheer guess here.

Your mileage may vary if you're using the upsampler or hi riz downloads...I haven't tried it that. Also I highly suspect this can be filter dependent...I was only using DSD F3 or redbook up sampled to DXD and F5


Speakers: Rockport Altair 2
Preamp: Robert Koda K10 Amp: Ayre MX-R
Cables: Transparent Opus MM2 Spkr, Opus MM2 & Trans Ref MM MM2 Intcnct.
Power Shunyata Triton/Typhon, Anaconda Zitron cords (x9)
Digital dCS Vivaldi DAC, Transport & Clock w/ Transparent Reference XL Digital cables
Phono: Grand Prix Monaco TT, Schroder LT arm, Jan Allaerts MC2 Finish & Lyra Atlas, Nagra VPS/VFS
Racks: Grand Prix Audio Silverstone F1 (x2)

[wizard]

The Stute price is now $39000!!

[Eichebaum]

Does anyone have already listened to the combo Stanford Perf10 + Vivaldi?

[custodian]

The price is now $39000!!

Probably because Oscilloquartz have stopped production of the BVA that they use.

[wizard]

Specs of the $39000 Stute clock:

Rubidium Unit

Phase noise :
<-140dBc / Hz (100Hz)
<-150dBc / Hz (10KHz representative value)
Accuracy at shipment : ±5×10-11
Warm-up time : <10 minutes (time required to lock and gain practical accuracy)


The €1700 Quartzlock A1000A has better phase noise specs:

-145dBc 100 Hz
-157dBc 10 KHz

[TLi]

I have brought this GPS disciplined oscillator, not expensive at all but very effective. It is linked to the external reference of Vivaldi clock. The input signal has to be set to TTL for best performance.


The image and details are obviously improved. I would recommed anyone using Vivaldi clock to give it a try. I'm glad I did.

[Eichebaum]

The output impedance of the Sforzato BVA Clock is 50ohm. The input of the Vivaldi clock is 75ohm. Will I need an adaptor? Will it deteriorate the signal?

[Eichebaum]

I've asked dCS. The answer:

"It is hard to tell because information for this product range online is so limited.
I do not expect the impedance mismatch to be a problem, but the PCM-01 appears to output only 7dBm, or about 10mV rms into 50 ohms. The Vivaldi Master Clock’s Reference Input was designed for at least 0.5V rms, I doubt that it will lock to such a low level signal."

[Stbo]

I have brought this GPS disciplined oscillator, not expensive at all but very effective. It is linked to the external reference of Vivaldi clock. The input signal has to be set to TTL for best performance.


The image and details are obviously improved. I would recommed anyone using Vivaldi clock to give it a try. I'm glad I did.

TLi I have had mine GPS disciplined oscillator for a week now and I agree with you, a very cheap upgrade. Better focus, more air in soundstage and improved low level resolution. Now I'm waiting for a linear power supply and a Jorma clock Cable, that will probably gain another notch.

[TLi]

TLi I have had mine GPS disciplined oscillator for a week now and I agree with you, a very cheap upgrade. Better focus, more air in soundstage and improved low level resolution. Now I'm waiting for a linear power supply and a Jorma clock Cable, that will probably gain another notch.

Glad to know someone actually share my experience. Good power supply and cables make a big difference.

[custodian]

Not updated this for a while.

It's interesting to compare the clock technologies. A GPS signal is going to do absolutely nothing for phase noise/short term stability but if you have one and you like it then great. Given the very low cost of rubidium modules on the surplus market, that would be my choice for a low cost upgrade. Look on eBay: you will find very good units for $250 which require just a 15v power supply and can be simply programmed to output any frequency up to 17mHz

I continue to be delighted with my Oscilloquartz 8607 BVA clock which totally outperforms any other clock I've heard. Concerns expressed about output level being too low to allow DCS clock to lock are rubbish: absolutely no problem.

No commercial replacement yet for the 8607 BVA but I see some high stability OCXO clocks are pushing closer to BVA stability numbers.

[jpspock]

Very intersting post. I looked to the 8607 bva, not easy to find. But is it easy to connect it to a scarlatti clock and how?

Thx for your help.

[Eichebaum]

Is the OCXO HSO14 from Rakon as good as the BVA 8607?

[Eichebaum]

I've bought the Cybershaft Limited OP15 and it made a huge difference in my Vivaldi+MBL system. It's a bargain for 2k.

[custodian]

Is the OCXO HSO14 from Rakon as good as the BVA 8607? Don't know the answer. The specification for short term stability looks very good. I can't see from their data sheet if it is an SC cut crystal. In any case it's a somewhat academic comparison given that Oscilloquartz no longer produce the 8607

In reply to the other recent question on connectivity, the 10mHz master clocks usually out put a 50 ohm impedance signal so you will need a small 50-75 ohm converter transformer and then connect into the external master clock input on the Scarlatti which expects to see a 75 ohm signal.

Watch out for the PSU. Not much point going to these lengths then powering the master clock from a dirty switched mode psu

Note that Quarzlock, the U.K. Producer of both selected performance OCXO as well as very convenient high quality rubidium oscillators, is no more. The founder died and the business has been closed

[Anatta]

Wonder how much these oscillators cost:

https://www.vectron.com/products/ocxo/ox-204.pdf

https://www.vectron.com/products/ocxo/ox-174.pdf

[SCAudiophile]

I've bought the Cybershaft Limited OP15 and it made a huge difference in my Vivaldi+MBL system. It's a bargain for 2k.

It's great to hear you like that clock; I have their dual-masterclock 10Mhz with Rb and OCXO circuits. I'm never going back to not having a 10Mhz clock in the system!!!

[SCAudiophile]

Will post some more info a separate thread within the "Digital" portion of this forum on the clock I am very happy to have found and that Eichebaum also purchased one of their offerings so that others may benefit and comment separately.

[jpspock]

Dear zephyr, i saw the link you gave on wbf, but all is in japan, and I don't understand it. Is it possible to have something in english? I am very interested for my scarlatti clock.

[SCAudiophile]

Good Morning! If you have Google Chrome as a browser, you can bring up the page and let it translate over to rough English. That's all I could ever do myself and then to send them questions.

There is a page link on the left hand side "For Overseas....written in English".

I extracted the attached to PDF format, their home page and the english sub-pages...(see attachments)

[audioblazer]

Eichebaum. Noticed that u bought the cybershaft unit . Have u resolve the output 50ohm of cybershaft & input 75ohm of your equipment ? I have Aurender W20 with an input of 75ohm & has its own OXCO clock . So wondering whether it will help with cybershaft . Used to own MSB Select with Femto clock & it's an improvement connected to W20

[SCAudiophile]

Eichebaum. Noticed that u bought the cybershaft unit . Have u resolve the output 50ohm of cybershaft & input 75ohm of your equipment ? I have Aurender W20 with an input of 75ohm & has its own OXCO clock . So wondering whether it will help with cybershaft . Used to own MSB Select with Femto clock & it's an improvement connected to W20

Aurender's email response to a related question from me yesterday;

"- 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."

Justubes responded on this same topic/question in another forum yesterday as did I. I hoping he adds his thoughts here as he had some great feedback on this posted recently. Justubes?

[SCAudiophile]

Dear zephyr, i saw the link you gave on wbf, but all is in japan, and I don't understand it. Is it possible to have something in english? I am very interested for my scarlatti clock.

Did the pages I downloaded and posted on an earlier reply in PDF format help? Do you have any other questions?

[jpspock]

Thanks for your support. Didn't you have in his time a stanford clock?

[SCAudiophile]

Thanks for your support. Didn't you have in his time a stanford clock?

You are very welcome....I've owned an Esoteric G-0s many years ago followed by an Esoteric G-03x until the MCLCK in the D-02 DAC sounded superior to me with 22.xxx Mhz reclocking. I had been looking at SRS PERF10 from Stanford, Antelope 10 Mhz clocks (they were very slow to respond and arrogant when they did leaving the hard questions unanswered). The problem Antelope response is noted as is their poor phase noise characteristic of their implementation (others have noted and reported this), the SRS PERF10 was almost impossible to find, had a long wait time for new and an exorbitant price tag for something that looked like it belonged in a lab versus in a high-end system.

I found the Cybershaft only by searching on HiFiShark for master clocks; got very luck indeed....

Let me know how else I can help...did you get one for your Scarlatti clock?

[jpspock]

Which clock do you have, premium, soul other? I am looking for one in a near future.

[SCAudiophile]

Which clock do you have, premium, soul other? I am looking for one in a near future.

As I've owned an Esoteric G-0s in the past and followed that with a G-03x (more musical I found and less 'perfect', sometimes parts-per-billion isn't all it's cracked up to be, sometimes part-per-million is more musical I have found), I ordered the RBOCXO-01 (dual master clock which is a combination of chassis containing a separate Rubidium-based 10 Mhz 50-ohm output section as well as a separate section with an OCXO "Ultra Premium" 10 Mhz 50-ohm output section).

Having listened for many weeks to the Rb side driving my Esoteric D-02 at 10Mhz (and the D-02 in turn drove the P-02 transport at "MCLCK" 22.xxx Mhz), I found the Rb side very good but have been using the OCXO side of the dual master clock exclusively as the phase noise and all other aspects are so much better than the Rb side and more importantly, sound stage is much bigger, deeper, more precise yet still more musical and overall so much more enjoyable. Kenji tells me the OCXO Ultra Premium is a much better match for most of the music out there all the way back to the match with the clocking setups used during mastering. Not so many recordings are mastered using full Rubidium or Cesium setups, most of the time it is (told to me) to be OCXO based so for some reason, the match during playback seems better as well. All this info given to me after I found I liked the OCXO side playback much better which candidly was a surprise as my background is in quantum physics, chaos & applied mathematics so I was a "bigot" for Rubidium implementations for a long time due to the whole "parts per billion" marketing ploy...

If I had to do it all over again, I would stick with the top of the line Ultra Cybershaft Premium OCXO implementation ("Ultra Premium" or "Ultra Premium Limited") and skip the Rb dual-clock.

There are recordings on my shelves that sound equally good with Rb as they do with OCXO (to my ears) among them all the Esoteric SACDs that I've tried and a good number of the JVC and other XRCD2s out there that I've tried as I believe they were all mastered using either Esoteric or JVC Rubidium-oscillator based devices.

All that stated, the guys at Esoteric may change the game considerably with the Grandioso G1 as though it is reported to be pure Rb in nature, I have a feeling I will need to try that one as well as early reports from friends in Japan tell me the nailed it when it comes to a higher-order Rb implementation with respect to better phase noise characteristics, etc...(note: this is all hearsay at this point...).

[Eichebaum]

Eichebaum. Noticed that u bought the cybershaft unit . Have u resolve the output 50ohm of cybershaft & input 75ohm of your equipment ? I have Aurender W20 with an input of 75ohm & has its own OXCO clock . So wondering whether it will help with cybershaft . Used to own MSB Select with Femto clock & it's an improvement connected to W20

I'm using a 50ohm cable from Cybershaft. It works flawlessly.
I'd asked DCS an Cybershaft before buying the clock and they said they were compatible.

[SCAudiophile]

This chart really puts things in perspective (many thanks Elberoth!);

48139

My existing RBOCXO-01 dual-master clock (Rb and OCXO side) measures as follows;

48152

I have a test version of an Ultra Premium OCXO OP14-level with upgrade SSI-equipped power supply (from Cybershaft Limited clock) on the way to experiment with that measures as follows. Should be interesting!!!

48153

The OCXO OP14 unit also has a SiC Schottky barrier diode-equipped custom power supply with custom R-core transformer.....phase noise specs of -114db at 1H and -133db and better at 10Hz are extremely impressive and as of this morning after installing it yesterday, it sounds amazing!

[custodian]

I'm using a 50ohm cable from Cybershaft. It works flawlessly.
I'd asked DCS an Cybershaft before buying the clock and they said they were compatible.

They will work but I suspect that without taking steps to match impedance, you will not get optimum sound quality. An inline 50-75 matching pad will sort that very cheaply.

[Eichebaum]

They will work but I suspect that without taking steps to match impedance, you will not get optimum sound quality. An inline 50-75 matching pad will sort that very cheaply.


Which one would you recommend?

[SCAudiophile]

Which one would you recommend?

An Acrolink 50-ohm BNC:BNC if you can find one new or in like-new condition. The 'holy grail' is the Esoteric Mexcel 8N-A2000 but they seem to have disappeared from availability since they've been discontinued.

Sergeui at Stealth cables will also build you an absolutely spec.-compliant and certified Varidig Sextet V16 or V16-T BNC:BNC from what I found out last week. His cables are well respected in both the digital and analog world.

Check Hifishark.com, ask Ivan, etc....if you are purchasing online, make sure you check for authenticity, i.e. Esoteric or Acrolink markings on the BNC barrel, the cable spec, model, etc...on the cable braid and proper box with label, etc...

As an aside, (I would post it properly if you were interested) I have a custom-built Kubala-Sosna EMOTION level 50-ohm cable (with proper connectors of course for 50-ohm) 1.5 meter cable that I am no longer after about 4-5 months of use as I was able to find 1 8N-A2000 that I also like very much. Send me a private message if anyone is interested.

Caelin and others have commented that for short lengths, the difference between 75-ohm and 50-ohm is negligible and that you should be able to utilize a good 75-ohm cable in place of 50-ohm with appropriate caveats for square versus sine wave, etc... From my point of view (trying both) for 10-Mhz "sine wave" type signals though, 50-ohm is a must as there is a small difference in timing and image accuracy that you can hear with a proper 50-ohm cable even compared to the 3 high-end 75-ohm contenders that I own.

For what it's worth....

[Eichebaum]

An Acrolink 50-ohm BNC:BNC if you can find one new or in like-new condition. The 'holy grail' is the Esoteric Mexcel 8N-A2000 but they seem to have disappeared from availability since they've been discontinued.

Sergeui at Stealth cables will also build you an absolutely spec.-compliant and certified Varidig Sextet V16 or V16-T BNC:BNC from what I found out last week. His cables are well respected in both the digital and analog world.

Check Hifishark.com, ask Ivan, etc....if you are purchasing online, make sure you check for authenticity, i.e. Esoteric or Acrolink markings on the BNC barrel, the cable spec, model, etc...on the cable braid and proper box with label, etc...

As an aside, (I would post it properly if you were interested) I have a custom-built Kubala-Sosna EMOTION level 50-ohm cable (with proper connectors of course for 50-ohm) 1.5 meter cable that I am no longer after about 4-5 months of use as I was able to find 1 8N-A2000 that I also like very much. Send me a private message if anyone is interested.

Caelin and others have commented that for short lengths, the difference between 75-ohm and 50-ohm is negligible and that you should be able to utilize a good 75-ohm cable in place of 50-ohm with appropriate caveats for square versus sine wave, etc... From my point of view (trying both) for 10-Mhz "sine wave" type signals though, 50-ohm is a must as there is a small difference in timing and image accuracy that you can hear with a proper 50-ohm cable even compared to the 3 high-end 75-ohm contenders that I own.

For what it's worth....

Tks. I'll try a matching pad 50-75ohms with my cable and see what happens.

[PASSFREAK]

I will connect my K-03X / G-02 master clock generator with an 1 meter long transparent reference digital BNC:BNC 75 ohms.The frequency selected in the G-02 will be 10 MHZ, my 75 ohms cable is ok or i need a 50 ohms cable for better results with the 10 MHZ frequency?
Thanks a lot guys!

[SCAudiophile]

According to many people including Caelin from Shunyata and Ivan who know much more than I, for these short lengths, 75 ohm should work well.

I do favor 50ohm over 75 ohm personally if the connection spec of the device calls for it and do use such cables with extremely good results.

[custodian]

The choice of 50 or 75 is not arbitrary. The dcs 10mhz input is designed for 75ohms. If your external master is designed to see 75ohm, then use a 75ohm cable, anything else will produce reflections in the cable.

If the master clock is designed for 50ohm connection, then use either a 50 or 75ohm cable with a correction pad at the correct end.

[Masterlu]

The choice of 50 or 75 is not arbitrary. The dcs 10mhz input is designed for 75ohms. If your external master is designed to see 75ohm, then use a 75ohm cable, anything else will produce reflections in the cable.

If the master clock is designed for 50ohm connection, then use either a 50 or 75ohm cable with a correction pad at the correct end.

The design engineers at Esoteric say otherwise, and so do my ears. Just saying, not trying at all to be argumentative.

[CGabriel]

I explained this extensively on another post or site. I really don't remember where.

But without getting into the technical differences between "transmission line" theory and signal transmission governed by simple LCR, I can give a simple guide. If you want to read about transmission lines refer to wikipedia - there are very good explanations.

If a cable is NOT operating as a "transmission line" then the characteristic impedance of the wire, the interface and the connectors are irrelevant. The operating principles are govermed by simple impedance (inductance, capacitance and resistance) of the cable.

Whether a cable is operating as a transmission line is determined by the transmission frequency and the length of the cable. As either the frequency or the length of the wire increase the more likely the cable will function as a transmission line.

At 10Mhz a cable that is a little over 4 meters in length will just be on the border of operating as a transmission line. If the cable is only a meter to two meters in length it will not matter what its characteristic impedance is. That does mean they will all sound the same however. Quality of the conductor and the type of dielectric will affect the sound quality.

But with all that being said, I agree with "custodian" - if you don't already have a cable, get a cable that has the specified characteristic impedance. If the cable length required is near or beyond 4 meters you should definitely get the correct impedance cable.

[SCAudiophile]

Thank you Caelin!

[custodian]

The design engineers at Esoteric say otherwise, and so do my ears. Just saying, not trying at all to be argumentative.

Whilst the design engineers at DCS say that external clocks such as rubidium do not improve the sound in any case. That diversity of opinion is one of the stimulating things about this hobby.

In terms of subjective listening, the particular 50 ohm master clock cable from my Oscilloquartz 8607 BVA oscillator plus 50/75 ohm adaptor at dcs end made a worthwhile improvement in sound compared to sound using a number of alternative high end 75 ohm (allegedly!) digital cables without matching pad at the bva end.

May have been particular cable effects: may have been a function of ultra low phase noise of BVA oscillator making differences more noticeable; interesting to speculate.

[SCAudiophile]

An external purpose built clock with low phase noise and high accuracy makes a difference in several of my systems over the years. 3 clocks under my belt over time,....they are essential IMHO

[custodian]

An external purpose built clock with low phase noise and high accuracy makes a difference in several of my systems over the years. 3 clocks under my belt over time,....they are essential IMHO

I couldn't agree more.

[Masterlu]

An external purpose built clock with low phase noise and high accuracy makes a difference in several of my systems over the years. 3 clocks under my belt over time,....they are essential IMHO

I'm on watch for my 4th clock. :confused-18:

[SCAudiophile]

I'm on watch for my 4th clock. :confused-18:

and my guess would be that you are referring to a Grandioso G1??? :crowd:

[CGabriel]

Whilst the design engineers at DCS say that external clocks such as rubidium do not improve the sound in any case. That diversity of opinion is one of the stimulating things about this hobby.

In terms of subjective listening, the particular 50 ohm master clock cable from my Oscilloquartz 8607 BVA oscillator plus 50/75 ohm adaptor at dcs end made a worthwhile improvement in sound compared to sound using a number of alternative high end 75 ohm (allegedly!) digital cables without matching pad at the bva end.

May have been particular cable effects: may have been a function of ultra low phase noise of BVA oscillator making differences more noticeable; interesting to speculate.

"Custodian" as you are well aware, there are electrical and engineering objective principles and then there is what can be "heard" with a high-end audio system. There are many things that I can hear but cannot measure nor do they make any sense with our current level of defined science. Given the quality and resolution of your system I would give your opinion on this a lot of credence. It would be interesting to be able to compare two cables of the same type and quality of construction with a reference master clock.

We make a great 75 ohm clock cable but don't currently have an equivalent in a 50 ohm. Since there seems to be so few quality 50 ohm cables I have a prototype run of 50 ohm being produced. I will let you know when it is available. Perhaps you would like to be a beta tester for the cable?

[custodian]

Caelin, I would be delighted to help with beta testing.

I think the Oscilloquartz 8607 BVA clock does set a very high standard for master clock use and I would certainly be keen to try anything that might squeeze a bit more sound quality from the system by changing the clock cabling.

[CGabriel]

Caelin, I would be delighted to help with beta testing.

I think the Oscilloquartz 8607 BVA clock does set a very high standard for master clock use and I would certainly be keen to try anything that might squeeze a bit more sound quality from the system by changing the clock cabling.

PM me please.

[ariess]

PM me please.


Caelin

I have an Esoteric K01X using a master clock, Esoteric G01. Esoteric recommends a 50 Ohm cable but I am using a Wire World Platinum starlight 7 which is 75 ohm. I'd be happy to beta test your 50 ohm clock cable (I use Shunyata Sigma for all my power cables).

Adam

[SCAudiophile]

"Custodian" as you are well aware, there are electrical and engineering objective principles and then there is what can be "heard" with a high-end audio system. There are many things that I can hear but cannot measure nor do they make any sense with our current level of defined science. Given the quality and resolution of your system I would give your opinion on this a lot of credence. It would be interesting to be able to compare two cables of the same type and quality of construction with a reference master clock.

We make a great 75 ohm clock cable but don't currently have an equivalent in a 50 ohm. Since there seems to be so few quality 50 ohm cables I have a prototype run of 50 ohm being produced. I will let you know when it is available. Perhaps you would like to be a beta tester for the cable?

I'm on my 3rd and 4th master clocks over the years (1. Esoteric G-0s, 2. G-03x and as of late, 3. Cybershaft 50-ohm 10Mhz Ultra Premium OP14 single OCXO and 4. Cybershaft dual-masterclock (Rb and OCXO).

I currently have a Kubala-Sosna EMOTION 50-ohm cable and an Esoteric 8N-A2000 50-ohm cable also having tried Kubala-Sosna 75-ohm EMOTION and another brand's high-end 75-ohm cable.

I would be glad to help with the beta. As an aside, I've owned my share of Shunyata over the years (Hydra8, Hydra6, 4 Anaconda VX, 4 Anaconda, 3 Python power cords and miscellaneous others) and would be glad to help out.

[justubes]

Glad to see this topic alive.

There seems to be a few factors such and cabling to get a taste of what low phase noise can bring to the system. Again, this is a whole area of optimising by itself.

From going to rubidium to ocxo, i felt was the right direction in sound which i personally felt gave better tones and naturalness over the more exciting sound of a rubidium clock.

My interest in the Mutec which uses a 1ghz crystal has been all but raves lead to more educational readings. Despite the terrible phase noise of such a high frequency oscillator. Is something else contributing to the receptiveness by users?

I came across a Japanese site which blogs on the various test, by scope and listening and revealed very interesting findings.

From a start, the type of clock, whether rubidium of ocxo may be best chosen on the genres of music listened to.

Psu and cables again contributes to the sonic result whether a particular clock will sound good. It even goes to lengths to state a steel housings interaction with the magnetic fields of the power supply affecting jitter and was measured with lab equipment.

So low phase noise may not the sole determinant of sonic outcome.

There is mention also how various brands of ocxo's tested had a different sonic characteristic. I read that this characteristic is independent from phase noise which was not the main focus. We all know ocxo do have better phase noise and most tcxo used in the majority of cdps and dacs.

I myself am not sure of whether my current ocxo at 116.9db/1hz together with the chosen psu and cabling resulted in a natural, zero glare for all genres of music.

[jpspock]

To scaudiophile,

Can you share your expériences with the 4 clocks you had. I would like to use with my scarlatti clock an ocxo premium cybershaft,so your impression will be highly appreciated.

[custodian]

To scaudiophile,

Can you share your expériences with the 4 clocks you had. I would like to use with my scarlatti clock an ocxo premium cybershaft,so your impression will be highly appreciated.

When I was doing some work at DCS with Quartzlock on improving the master clock, I remember looking at the built in ocxo oscillator in the Scarlatti and recognising it as a standard product. The significance of that is that the standard offering will have a performance spread (within specified limits). Many of the standard oscillators from that supplier are also available in selected versions where the top end of the tested performance distribution curve is selected and sold at a premium. These will carry a suffix in the model type to identify them.

My point is that there is nothing (apart from warranty considerations) to stop a customer replacing the standard ocxo chip with a specially selected higher performance variant of the same ocxo chip. It might offer much the cheapest and simplest clock upgrade of the dcs product range.

Just a thought....

[SCAudiophile]

Guys...will send a detailed response after the holiday. Happy Thanksgiving!!!!

[jpspock]

Hi Sc, no response for us?

You talked about an op14, i thought it was something new as it appears a few days ago only.

[SCAudiophile]

I was on vacation for several days and just got back to work and am swamped. As soon as I can respond, I will in detail...

[SCAudiophile]

Hi Sc, no response for us?

You talked about an op14, i thought it was something new as it appears a few days ago only.

Here is my short history with master clocks; there are actually five if you count the mid-term stop using solely the MCLK functionality in the new Esoteric D-02 which is by far the best onboard clock (IMHO) they’ve used to date…

I started out like many I’ve discussed this topic with believing only what most market literature tells us, namely that “parts per billion is better than parts per million, and that’s all that matters….and that ‘atomic’ clocks are ‘more precise’ than OCXO implementations”. Taken individually, and in certain disciplines, each of these sub-phrases is definitely true. There’s much more to use and evaluation of the end result of any setup that includes an internal or external ‘master’ clock. That stated, all the clocks below have added alot to my system’s performance at the various points that I’ve owned them and candidly, I knew nothing at the beginning of this journey about 9 years ago and have learned enough to get by, over the course of time so in other words, I’m no expert. Learning the basics of clocking both as part of the mastering as well as the playback process both for audio and video is essential to understanding the place of various master clocks for ‘frequency multiple’ clock-sync (44.1Khz on up…) as well as true ‘master clock’ (10 mHz ‘atomic’ or other reference clocks….).

I don’t know what the DCS unit in question that was named above will accept (44.1 and multiples only at 75-ohm versus 10 mHz 50-ohm); I am hoping you get enough from my response to help you towards your decision….

FIRST CLOCK: Esoteric G-0s, rubidium oscillator parts-per-billion level accuracy spec clock; 44.1 kHz and 48 kHz (and 2x, and 4x multiples), 75-ohm clock output capability for multiple devices. Had the ability to take a 10 mHz master clock reference to baseline the G-0s performance but I did not utilize it in that way. This drove my Esoteric P-03U/D-03 Universal Transport and DAC setup in a 7.1 Home Theater and 2-channel hybrid setup.

What I noticed: Outstanding improvements in video clarity, sharpness/edge definition, etc….This verified by my ISF Engineer during detailed calibration sessions both with and without the clock viz. use of a “Sencore” professional testing device. He stated the P-03U video board was
the best DVD-Video 480p up to 1080i playback device he’d ever tested but that having the G-0s engaged made the video performance ‘insane’ using both a 200 pound pro-grade Sony Direct View CRT and later a high-end Samsung 5088W limited run RDLP television. All that true for video also later using a Lumagen 1080p pro scaler and video parametricEQ device but with superior video color and gamma behavior and results when using the Lumagen in the chain after the P-03U/D-03/G-0s video output chain. For audio, I noticed that the G-0s at 44.1, 88.2 or 176.4 kHz (particularly the latter) brought razor sharp image (placement of instruments and voices) behavior to CD, XRCD, SACD and DVD-A. Bass and Sub-bass accuracy most notably also took an appreciable jump. It’s been a few years however, I do not remember my setup at the time being as natural sounding as it is today but that is due only in small part to the use of the hyper-precise Rb-based master clock as there were many other variables at play in terms of the interconnects, power cords, power conditioning and components I was utilizing overall. My system today is much more resolving and yet much more musical and involving overall. Sound stage and imaging together with overall musical presentation is much more palpable both with and without any external master clock device. I would have liked to still have the G-0s (I do not) and be able to put it into my current system to see how it affects playback in a system that is as good musically as my old system was for precision.

One thing I’ve thought about over the years since moving away from home theater & 2-ch hybrid setups to firmly be only in the 2-channel world is the disparity between the no-compromise improvements the G-0s brought to my setup for video versus the ‘great improvements with a couple of compromises’ that it brought for audio. I have wondered if this is the difference between using the ‘perfect clock’ in terms of timing accuracy (think parts per billion versus parts per million clocks that have better phase noise and Allen Variance and lower harmonic distortion) versus one with much more than simply pure discrete time-sync pulse accuracy going for it. Many of these clocks and the people who design them seem to have come over from the ultra-high end scientific work world many years ago where it’s about time precision versus what we think of as musically accurate and well-matched clocking without the side effects of harmonic distortion and phase noise creeping into our audio playback. My hunch tells me that the timing precision all out approach of the Rb-based G-0s was perfectly suited to video and well suited, but not perfectly to audio playback as the latter takes much more than PPB ‘perfection’…..

There is also the interesting side note to consider that I’ve heard from more than one industry guru, namely that most music happens to be mastered with ultra high precision OCXO-based implementations, not rubidium or the even more expensive cesium standard. At least 3 people, one of whom designs these clocking devices and the other 2 who design playback devices (transports and DACs) have said that matching the master clock in playback as closely as possible to the master clock type and characteristics of what is used during mastering will always yield the ultimate results. There are notable exceptions on the music mastering side (Esoteric’s SACDs, many of JVCs XRCD and XRCD24 releases and I believe all of their XRCD2 20-bit releases) that were laid down using JVC or Esoteric or other Rubidium clock implementations….

Subsequently sold the G-0s for various reasons and thought my system became a bit more relaxing to listen to after the hyper precise clock left the system. I did however miss some of the improvements related to precision and image placement.

SECOND CLOCK: After spending about a couple years without a clock after the departure of the G-0s, but with the same P-03U/D-03 setup, I picked up an Esoteric G-03x OCXO-based 44.1 kHz multiple clock…in a nutshell after breaking in this clock and finding that like the G-0s, 176.4 kHz on 75-ohm feed into my D-03 DAC and P-03U Transport was the best overall re-clocking frequency to match the system and how I had it configured for native DSD playback for SACD and 176.4 kHz up-sampling for RBCD formats. What I noticed in this setup was that I had ‘just enough’ increase in precision of imaging, soundstage in all 3 dimensions, etc…but was achieving a more natural and musical presentation. I now know that going back and comparing the full specs on both clock circuits, not just PP/B versus PP/M, but also including phase noise and Allen Variance/Deviation of the units, that the G-03x was a bit better overall in spec. as a unit, not just a more precise clock pulse output. The result, at least to my ears, was a better and more musical presentation that did not take more than it gave in terms of making the music that much more real and believable…

PIT-STOP: Upgraded to a P-02 and D-02 transport and DAC from Esoteric and from day1, utilized the G-03x as the master clock, again at 176.4 kHz output to feed the P-02 and D-02 through their break-in period and for a good while after. The P-02 and D-02 improved the playback of all RBCD and SACD to a level over their 03 counterparts that it is hard to determine if any of the improvement was due to the G-03x being in use or simply because the new DACs and overall design approach and transport in the 02 series was SO much better than their 03 generation predecessors. Very good results but as you’ll see, I think the difference really was the level of improvements in the 02 generation themselves…

THIRD CLOCK: Pulled the G-03x totally out of the system one day and set the D-02 to “MCLK” frequency output and drove clocking for the P-02 from the D-02’s built in OCXO based clock based upon things I’d read or spoken about online with various folks Esoteric and various users of the units in the US and Asia-Pacific……one word comes to mind, “WOW”. The onboard OCXO clock implementation at 22.xxxx mHz in the 02 must be so much better than the aged implementation in the G-03x that it instantly transformed the music to be even more natural and palpable while still giving even better even better imaging and sound-staging….I very happily ran this combination with no outboard master clock for quite a long time.

FOURTH CLOCK: For budgetary reasons, and the fact that I was extremely happy with the MCLK 22.xx output of the D-02 clocking circuit, did not have 20K to drop on an Esoteric ‘big boy” clock, and because I did not want to had another large box to the system (to further add to ongoing WAF problems), I was looking for a discrete 10 mHz master clock solution to add a more precise baseline clock to the D-02 but still use its MCLK output to drive itself and the P-02. The usual suspects emerged,…SRS PERF10, Antelope Isochrome 10M, BVA, home-built with an OCXO stabilized module drop-in, etc….SRS had a great rep and were mostly helpful to deal with but their price and mostly their lead-times plus the scarcity of used units caused me to stop looking at these units; when you add the fact they look like a great piece of lab equipment and not an audio component, I feel I made the right decision. Getting answers out of Antelope for their 10M products proved difficult at best with a dose of arrogance and ignoring of questions/lack of follow-up put me off dealing with them totally.

Via use of hifishark.com, I stumbled on Cybershaft Japan as an option via listings on various sites for high-quality 10 mHz master clocks. They make premium and ultra-premium 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. They are rated for 100-120V and 50-60Hz use (also available for 220-240v and 100v configs) which makes them perfect for US or Japanese usage. They supply all their test and calibration results for each unit prior to shipment1 year unconditional warranty. The site can be found google-ing for 'Cybershaft Japan'.

I have the Cybershaft Rb+OCXO 'dual master clock' offering up and running quite a while now and I am extremely impressed by the build quality of the unit and the customer service provided by Hasegawa-san. He goes to great lengths to ensure all questions are answered and provides unit-specific test data for ALL testing of the unit including Allan Deviation, reference measurement devices used, etc....It's the most specific and open backing data of what a unit truly does after it is built that I have ever seen.

I broke in both sides of the dual master-clock fully from day 1 by keeping them both powered on, but I initially had this connected as follows;

Cybershaft Rb-output=>10mHz=>Esoteric D02 (WRD CLK IN, 10 mHz)=>Esoteric P02 (MCLK 22.xxx mHz frequency from the D02)

The Cybershaft adheres to a strict 50-ohm output spec. as does the D-02's 10 mHz clock input; while I tried 75-ohm cables on various peoples' recommendation, I found the best results aurally are gained by use of a true 50-ohm compliant cable + connectors. Put another way, the Cybershaft clock is providing an ultra-high 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 10 mHz input signal from the Cybershaft to drive the WRD CLK Input of the D02 over the D02’s internal clock alone. All was extremely good before but I find a substantial amount of additional precision in image size and placement, better soundstage 3 dimensionality and an even more musical presentation overall of the system as a whole. On the edges of some troubled recordings, I could still make out some digital hash and other artifacts that originated from the recordings even though the rubidium side of this new clock’s 10 mHz behavior brought alot of improvement to my system as a whole.

The final step with the RBOCXO-01 clock was to switch from the Rb to the OCXO 10 mHz output to drive my D-02 and subsequently P-02 as follows;

Cybershaft OCXO-output=>10mHz=>Esoteric D02 (WRD CLK IN, 10 mHz)=>Esoteric P02 (MCLK 22.xxx mHz frequency from the D02)

Immediately upon making this switch and in the days and months that follow, all the improvements noted above were pleasant plus the absence now of digital hash and the inclusion of a bit more liquid nature of the sound, the ‘right-ness’ of each note and musical passage and overall better timing and pacing of the music. In short, my level of enjoyment at what I was hearing went up substantially and beyond what I ever expected with this reasonably priced master-clock.

Footnote: “OPxx” is the rating scheme for precision/phase noise/overall module quality that Cybershaft uses to hand-select and stratify each and ever OCXO module they test. I have no idea if this is standard in the industry but in short, the higher the number (OP14 better than OP12, etc…), the better the module tests in and of itself for clock precision, phase noise Allen Variance, THD, etc….

Footnote: Adding Stillpoints Ultra SS feet and bases plus HRS Damping plates to all my equipment in recent weeks including my clocks has refined my system sound playback even further…

FIFTH CLOCK: This is a loaner unit for testing and in my system for the last month so now fully broken in. It is a special build Cybershaft Ultra Premium “OP14” OCXO clock with an SiC-based Schottky barrier diode power supply. I don’t understand all the ins and outs of this but unit is equivalent to the “Limited” clocks that Hasegawa-san no longer makes as he is designing something new and improved for the future taking the best OCXO he has on the shelf currently, better than the one in my RBOCXO-01 by a small margin, and coupling it with a purpose-built high-end power supply. As the OCXO phase noise, etc…is so close to what I already had, the thesis was this may not make a big difference in the system and was committed to only to test the combination of a particular level of OCXO module with the SiC-enabled power supply. The results are as expected but with a kicker namely that this clock performs in every way at the same level of my RBOCXO-01’s OCXO output, however, there is a small but noticeable improvement in drop of noise floor, black backgrounds, timbral and spatial accuracy of every note and precision of soundstage/imaging without sacrificing any musicality. A worthwhile experiment and sounds great but as stated before this is a loaner unit and I have my eye on what might be designed for the future which is rumored to have any even better hand-selected OCXO module and better power supply; time will tell however and that’s all that I know at this point.

Hope this answers the questions above and creates alot of other ones so we keep this dialog going. Also, by no means is this to be interpreted as anything but a home audio junkie’s journey to improve his system and what I’ve learned and used along the way. There are many sharper and more capable people here and in the industry so if something does not make sense or doesn’t fully explain something above, please let me know.

Thanks for everyone’s patience who was waiting for this reply; I’m behind on my forum read/posts and this took some additional time.

Have a great day!!!!!

[custodian]

Thanks for posting an interesting and comprehensive summary.

A point you raise early on needs a bit of clarification; generally the better ocxo clocks have better short term stability and phase noise than any rubidium clock. I'm not sure why rubidium clocks can sound as good as they do in the right system.

I think pursuing picking the best possible ocxo and providing a top quality power supply is definitely a good path. With my home made clock using the amazing Oscilloquartz 8607 BVA ocxo. I spent some time experimenting with power supplies to wring out the last drop of performance. I still would like to put it all in a case like Sforzato used for their commercial clock using the same 8607 ocxo but for the time being it has to stay in an off the shelf case plus HRS damping plate.

[chessman]

Outstanding post!

[SCAudiophile]

Thanks for posting an interesting and comprehensive summary.

A point you raise early on needs a bit of clarification; generally the better ocxo clocks have better short term stability and phase noise than any rubidium clock. I'm not sure why rubidium clocks can sound as good as they do in the right system.

I think pursuing picking the best possible ocxo and providing a top quality power supply is definitely a good path. With my home made clock using the amazing Oscilloquartz 8607 BVA ocxo. I spent some time experimenting with power supplies to wring out the last drop of performance. I still would like to put it all in a case like Sforzato used for their commercial clock using the same 8607 ocxo but for the time being it has to stay in an off the shelf case plus HRS damping plate.

Excellent clarification,...thank you! I learned that in the past 6 months from my forays into these 10 mHz 50-ohm based clocks.

Esoteric Rb-based clocks cause music to sound as good as they do (in my experience iwth them) I believe due to the quality of the Rb circuit they use PLUS every other level of excellent design improvement they implement around it from the chassis and base plates to the outstanding power suppliers. Interesting project you made happen with the BVA. That module/circuit has a great reputation!

[SCAudiophile]

Outstanding post!

Thank you very much....

[custodian]

Excellent clarification,...thank you! I learned that in the past 6 months from my forays into these 10 mHz 50-ohm based clocks.

Rb-based clocks cause music to sound as good as they, particularly Esoteric I believe due to the quality of the Rb circuit they us PLUS every other level of excellent design improvement they implement around it from the chassis and base plates to the outstanding power suppliers. Interesting project you made happen with the BVA. That module/circuit has a great reputation!

Not sure I buy your comments on Rubidium circuits. Generally they have comparatively poor phase noise which should be critical. Also some of the commercial offerings use very ordinary switched mode power supplies. The rubidium unit is self contained and bought from an OEM supplier; not something fabricated by the audio equipment manufacturer. Certainly casework and wiring help but I'm not convinced any of the rubidium units do this any better than companies such as dcs do with their ocxo oscillators. But in spite of their quantitative performance shortcomings and often mediocre implementation, they can sound very good. As a cheap experiment, try buying one of the ex China Telecomms rubidium units ($1-200 on EBay) and a cheap 15v switched mode PSU and a simple case. it can still add something when used to provide a reference clock signal to a DCS or similar.

[SCAudiophile]

Not sure I buy your comments on Rubidium circuits. Generally they have comparatively poor phase noise which should be critical. Also some of the commercial offerings use very ordinary switched mode power supplies. The rubidium unit is self contained and bought from an OEM supplier; not something fabricated by the audio equipment manufacturer. Certainly casework and wiring help but I'm not convinced any of the rubidium units do this any better than companies such as dcs do with their ocxo oscillators. But in spite of their quantitative performance shortcomings and often mediocre implementation, they can sound very good. As a cheap experiment, try buying one of the ex China Telecomms rubidium units ($1-200 on EBay) and a cheap 15v switched mode PSU and a simple case. it can still add something when used to provide a reference clock signal to a DCS or similar.

Thanks for the note and feedback plus ideas; I was not as clear as I had hoped to be....my post should have read like this;


A point you raise early on needs a bit of clarification; generally the better ocxo clocks have better short term stability and phase noise than any rubidium clock. I'm not sure why rubidium clocks can sound as good as they do in the right system.

I think pursuing picking the best possible ocxo and providing a top quality power supply is definitely a good path. With my home made clock using the amazing Oscilloquartz 8607 BVA ocxo. I spent some time experimenting with power supplies to wring out the last drop of performance. I still would like to put it all in a case like Sforzato used for their commercial clock using the same 8607 ocxo but for the time being it has to stay in an off the shelf case plus HRS damping plate.[/quote]

Excellent clarification,...thank you! I learned that in the past 6 months from my forays into these 10 mHz 50-ohm based clocks.

Esoteric Rb-based clocks cause music to sound as good as they do (in my experience with them) I believe due to the quality of the Rb circuit they use PLUS every other level of excellent design improvement they implement around it from the chassis and base plates to the outstanding power suppliers. Interesting project you made happen with the BVA. That module/circuit has a great reputation!

==>I do agree with you based upon the last 6-9 months where I learned alot more on this topic and was no longer buying/using blind based upon a glitzy marketing spec (PP/B versus PP/M). Through some very expensive learning over the years and with finding a high-quality OCXO-based implementation that quite simply makes my system sound a whole hell of a lot better using a sub-$2K clock with a great OCXO implementation than the best Rb I ever owned or heard, for the reasons you state above. What I am very eager to see though is what will Esoteric pull off with their all-10 mHz/22.xx mHz true master clock, the Grandioso K1. I have to believe they are aware of the importance of all these factors. Wondering how this Grandioso-level rig will perform. I'm also looking forward to my next all-OCXO > OP15/17 level implementation (current tested modules are OP20) to be designed and made available in the future.

Hope this helps...let me know if I solved the confusion from my post or just created more! :D

[custodian]

I think it helped (a bit, anyway)

[jpspock]

Dear scaudiophile, or zephyr you changed your name I think, and custodian. I have read your reports with great attention and it is very helpful, thank you.

So scaudiophile, you are in contact with cybershaft and it seems they are serious and propose with the new OP 11-14 very competitive clock 10MHz compred to antelope, sforzato or perf10. I didn't receive any information concerning op 17 or upper, i will ask.

Concerning my approach, my search through the net showed me a lot of discussion with custodian. I discoverd you had a scarlatti stacks before. So you have for sure the experience of what is happened when a 10MHz clock is added to a scarlatti clock. Can you develop this for me? As you have a specific clock, unavailable for us, what do you think about cybershaft clock? So just for the fun.

And for both, the bnc cable must be a 50ohm, for the cybershaft, where can i get one, and does it make a problem with the scarlatti that has an entry of 75ohm.

Already many thanks guys.

[custodian]

With dcs Scarlatti stack, I have run several rubidium clocks from a cheap and simple China Telecom surplus unit from eBay, up to Quartzlock module. All of the rubidium clocks are designed to output via an SMA connector to 50 ohms. In all cases, sound changed from standard Scarlatti clock, generally to produce a better imaging result. The 50 ohm SMA in some units just goes through a short jumper to a BNC connector.

Working on a project with Quartzlock, I had an opportunity to try any type of frequency standard. The advice of the Quartzlock engineers was to try the 8607 BVA ocxo because it had the best available results in phase noise. Initial tests were with a simple set up with a 24v switched mode supply and the same sma to bnc jump lead to a 50 ohm bnc on the rear panel. Connecting this to the Scarlatti clock with a 75 ohm cable produced a very good result.

Trying to get even better performance, I used a 50 ohm lead direct from the sma on the ocxo case to a 50/75 ohm converter at the dcs clock reference input. Again a noticeable change for the better.

Final upgrade was to build a high performance power supply and fit clock in a decent case with mechanical damping: results outstanding!

Cybershaft clock? I can't comment because I've not had the opportunity to try one although the specs look very good at a very attractive price.

The end of production of the BVA Oscilloquartz 8607 was a great pity however it was difficult to make because of low yields. I understand that there might be an alternative sometime soon but no firm details yet.

For me, the next steps are to do more work on optimising the 50 ohm cable.

[SCAudiophile]

Dear scaudiophile, or zephyr you changed your name I think, and custodian. I have read your reports with great attention and it is very helpful, thank you.

So scaudiophile, you are in contact with cybershaft and it seems they are serious and propose with the new OP 11-14 very competitive clock 10MHz compred to antelope, sforzato or perf10. I didn't receive any information concerning op 17 or upper, i will ask.

Concerning my approach, my search through the net showed me a lot of discussion with custodian. I discoverd you had a scarlatti stacks before. So you have for sure the experience of what is happened when a 10MHz clock is added to a scarlatti clock. Can you develop this for me? As you have a specific clock, unavailable for us, what do you think about cybershaft clock? So just for the fun.

And for both, the bnc cable must be a 50ohm, for the cybershaft, where can i get one, and does it make a problem with the scarlatti that has an entry of 75ohm.

Already many thanks guys.
Let me know how I can give you a call tomorrow to answer your questions if that is acceptable to you.

[Masterlu]

Let me know how I can give you a call tomorrow to answer your questions if that is acceptable to you.

Mark... without him being a Subscriber, he cannot send nor receive PM's.

[SCAudiophile]

Thank you Ivan....did not notice that.

JPS: OP levels for OCXO modules above OP14 (from what I am told, remember, I'm just an owner of their clocks out of Japan) were exhausted and the Limited level of the clock that could range from OP15 to OP17 is not being produced any longer. I am told design revisions and new module acquisition are firmly under way. The process apparently is that hundreds (or more) of candidate modules are tested rigorously and this OP rating (which I don't know the source of, could be their in-house rating nomenclature) then assigned to each for any module that is not discarded. When they have a lot produced that scores highly, they apparently buy up the remainder of the entire run from the vendor, test them, assign levels and shelve them for future builds. Hope this answers the question in a more thorough way.

Having 2 clocks in the system right now at OP14 level (lower strata and one upper strata of the range), I can tell you that OP14 is more than sufficient to have the wow-factor. I cannot imagine what an OP17 or above would behave like; it must be truly special. I hope they wind up having these made and certifying them at a > OP15 and above level. I will definitely grab one....

As for 50-ohm cables,

- Shunyata is entering a testing phase per Caelin recently on a beta version of one of their high-end BNC:BNC cables certified for 50-ohm. My personal bet knowing his work is that this cable will be amazing

- I've talked at length to Sergeui at STEALTH; he definitely makes and will certify a pure 50-ohm version of his VARIDIG SEXTEX V16 or V16T cables...

- Esoteric/Mexcel made one in the past, the 8N-A2000 which is like "unobtanium" to find these days. I am extremely fortunate that there was one left locally and I was able to grab it from a good friend(!)

- Acrolink I believe also makes one that is either 6N or 7N

- I have an extra Kubala-Sosna 50-ohm 1.5 meter custom-made cable < 6 months old; if interested, let me know and I'll post it

- You can get a $35 USD cable that is absolutely certified for 50-ohm off Amazon; I tried one initially and it was a good start (for me)

- Other manufacturers may make them; I did not exhaustively research the topic...

- Many people have found no noticeable difference at 1-meter and 1.5 meter length using high-quality cables like Wireworld Platinum Starlight v7; Ivan can definitely tell you more

JPS: Become a subscriber; it's the best $25 USD you will ever spend :-) !!!

Let me know of other questions...have a great day!!!

[custodian]

Thanks for a very comprehensive summary.

The basis of their OP rating is interesting: I can only assume that the unavailable oscillator for the OP is actually the Oscilloquartz 8607. This was available in performance selected versions which might relate to their 16 and 17 levels.

The reason for the demise of this crystal is the difficulty of getting good yields. In simple terms, all components in the oscillator including the suspension are made from slices of the same crystal, removing any thermal or mechanical discontinuities which would affect performance.

The new owners of Oscilloquartz felt that the complexity and yield are no longer commercially viable. As mentioned, some alternative structures are in development and might appear. Remember though that the Audio market is not a significant customer for such products so it is not really in a position to drive the market.

Cost is certainly going to be an issue too. Given the near $40k price for the discontinued Sforzato clock which used the 8607.

The 8607 certainly gives the "wow" factor, so I hope that alternatives at similar performance emerge before too long.

[SCAudiophile]

Thanks for a very comprehensive summary.

The basis of their OP rating is interesting: I can only assume that the unavailable oscillator for the OP is actually the Oscilloquartz 8607. This was available in performance selected versions which might relate to their 16 and 17 levels.

The reason for the demise of this crystal is the difficulty of getting good yields. In simple terms, all components in the oscillator including the suspension are made from slices of the same crystal, removing any thermal or mechanical discontinuities which would affect performance.

The new owners of Oscilloquartz felt that the complexity and yield are no longer commercially viable. As mentioned, some alternative structures are in development and might appear. Remember though that the Audio market is not a significant customer for such products so it is not really in a position to drive the market.

Cost is certainly going to be an issue too. Given the near $40k price for the discontinued Sforzato clock which used the 8607.

The 8607 certainly gives the "wow" factor, so I hope that alternatives at similar performance emerge before too long.

Great points and feedback; thank you!

[justubes]

Thanks for a very comprehensive summary.

The basis of their OP rating is interesting: I can only assume that the unavailable oscillator for the OP is actually the Oscilloquartz 8607. This was available in performance selected versions which might relate to their 16 and 17 levels.

The reason for the demise of this crystal is the difficulty of getting good yields. In simple terms, all components in the oscillator including the suspension are made from slices of the same crystal, removing any thermal or mechanical discontinuities which would affect performance.

The new owners of Oscilloquartz felt that the complexity and yield are no longer commercially viable. As mentioned, some alternative structures are in development and might appear. Remember though that the Audio market is not a significant customer for such products so it is not really in a position to drive the market.

Cost is certainly going to be an issue too. Given the near $40k price for the discontinued Sforzato clock which used the 8607.

The 8607 certainly gives the "wow" factor, so I hope that alternatives at similar performance emerge before too long.

Look up Rakon HSO14 -120dbc/1hz which is an equivalent of the BVA8607.

I understand that it is priced similarly to the 8607

[SCAudiophile]

Look up Rakon HSO14 -120dbc/1hz which is an equivalent of the BVA8607.

I understand that it is priced similarly to the 8607

Thank you....according to certification reports I have on both the RBOCXO-01 and UPOCXO-OP14-A clock I have here, Hasegawa-san utilizes the BVA as a reference OCXO oscillator...

I may have an OP20-enabled clock here next year at some point.

[SCAudiophile]

FYI...this is the new web-page for the UPOCXO-OP14-A clock also with improved power supply that I am testing for over a month now with fantastic results;

’´�‚�¸“xOCXO ƒNƒ�ƒbƒN Premium OP•t (http://www.cybershaft.jp/a-products/premiumop.html)

*Reminder: Bring up in Google Chrome and elect automatic translation from Japanese.

[jpspock]

Yes but they don't have one for the moment...

[SCAudiophile]

I have one in my rig for testing so I know they build them; give it some time (don't know how much).

[vintage_tube]

I've read all 200 + posts and realize a lot of discussion on clocks and some regarding clock cables (BNC or RCA, 50 or 75 ohm).

Let me tell you, I'm a firm believer. Received these today -- at $2K for 1 meter and I need 3; well, that about taps me out & there is no way I could afford or would be willing to spend $12K per on a 1M Nordost Odin 2.

I'll expand a bit on my experiences going from a run of the mill 75 ohm BNC to these puppies a bit later. (Contacted Martin at dCS HQ & he confirmed 1 meter 75 ohm is the ticket for the Paganini 4 box).

For now, I'll just :stirthepot: in this thread since the other one is already corrupted.:D

Best Sirs,

Bob

http://i.imgur.com/1RXhs0u.jpg

[jpspock]

For cybershaft spécialiste. Wyatt about calibration ?

[SCAudiophile]

For cybershaft spécialiste. Wyatt about calibration ?JPS, what is your question? I do not understand your post?

[custodian]

For cybershaft spécialiste. Wyatt about calibration ?



I too would welcome clarification on your question. What parameters do you feel need calibration?

[bmichels]

If I get a dCS Rossini DAC + dCS's External Clock, so.... can I use the dCS's External clock to clock also the Aurender W20 ?

[SCAudiophile]

If I get a dCS Rossini DAC + dCS's External Clock, so.... can I use the dCS's External clock to clock also the Aurender W20 ?I believe the answer is yes...