Superclocks

[vortecjr]

My earliest recollection of the term "Superclock" that I have is as used by a company called Audiocom. They sold or still sell (I don't now) these cool looking clocks for use on CD players. Here is an image of one: 

  

[vortecjr]

Steve Nugent at Empirical Audio also use to use the term "Superclock", but no clue is it's related to, inspired by, or unrelated to Audiocom. I think now he uses the term "Turboclock". 

[Johnseye]

On 4/28/2017 at 8:35 AM, mmerrill99 said:

Well Uptone/Swenson's reasoning for better clocks (& therefore better signal integrity, lower jitter) was that it required less overhead at the chip receiving & processing the signal. The logic was that this reduction in overhead generated less internal noise on the ground plane of the chip & ultimately on the ground plane of the power distribution system to which the sensitive DAC chips are connected & effected by such small noise fluctuations.

 

Unfortunately, it appears that these noise fluctuations are very low in amplitude & difficult to measure.

 

Now how a clock on a purely digital upstream device can audibly affect the DAC requires a deeper system analysis  

 

+1

 

This is also discussed by Ken Pohlmann in Priciples of Digital Audio when explaining jitter.  Ken explains that this is possible anywhere in the digital chain, including the storage device.  Unless there is an effective method to strip the noise out, it can be cumulative.  However if each piece of equipment in the chain is frequency locked to a master clock the jitter is dropped at the input.  So if noise can begin from the drive where the music is stored we could make the assumption that a good clock at each device would help minimize noise along the chain.

 

@JohnSwenson or @Superdad do I have this right and can you explain the benefit of chaining USB clocks?  Are we just changing the sound, or is there a benefit from consecutive USB clocks?  If so, then why not a single device with multiple clocks, or is a physical interface necessary?

[Beolab]

On 2017-04-22 at 10:48 PM, Superdad said:

 

Reasonable points and questions: Yes, the oscillator manufacturers are measuring their clocks--and the performance of those is of course not at all the same as the jitter performance of a complete DAC.

 

I will tell one interesting story:

Crystek has gotten a LOT better making their XOs!  18 months ago John and I requested and received samples of their CCHD-575 (the one Jonathan linked to above).  Got 25.0MHz version (for testing in the ISO REGEN).  They sent us 3 samples, and they each came with individual phase-noise plots.

Whereas the data sheet on Crytek's web page shows -100dB for 10Hz offset (in the mid-20MHz f-range we are using), the plots for the 3 samples we got were -108dB, -110dB, and -112dB at 10Hz!   

Of course our first thought was that they hand-selected these and that production runs could not be anywhere near as good as these.  So I immediately picked up the phone and called Crystek (they are actually not that large a company; one sales engineer seems to handle the whole country).  They said no, the samples were not at all specially selected--just measured right off the line. And he said that their processes have improved so much that the $9.60 CCHD-575 (that's what I paid for the first 500 pieces; goes to $9.30 ea. @ 1,000) now outperforms their big $27 CCHD-957 as used in a lot of top-tier DACs.   I told him they ought to update the 575's datasheet on the web to reflect that.  Guess he did not relay that suggestion to their marketing department. 

 

Of course if you want to see eye-popping phase-noise performance, then check out the Pulsar Clock. -118dB to -123dB at 10Hz!  But it is 420 Euros...

 

This is very interesting to discuss  Alex, and i got two topics for you: 

 

If you elaborate a little with your knowlage and experience on how much better is the  acclaimed 26Nm 1ppm MSB Galaxy clock vs let say the Pulsar / Crystek CCHD595 clocks, and what is the fabrication cost of the Galaxy clock ? Is it the best of the best or could a company like Texas Instruments or Intel make much better for 1/100 of the price? 

 

 

Secondly, what is your thaughts about using a poorer streamer like a BlueSound Node II MQA using two W4s Remedy ( CCHD957 ) SPDIF clocks in a chain with LPS-1 Ultracap vs the top tier streamers like Auralic Aries , Aurrender W20, Antipodes , Sonorus, do you think it is the best result in the end? 

 

My experience is that the Bluesound + 2x clocks is on pair with my other top tier streamers, but i want to know your input on it. 

 

Have an great evening!  

 

/ Fredrik

[vortecjr]

45 minutes ago, Johnseye said:

 

+1

 

This is also discussed by Ken Pohlmann in Priciples of Digital Audio when explaining jitter.  Ken explains that this is possible anywhere in the digital chain, including the storage device.  Unless there is an effective method to strip the noise out, it can be cumulative.  However if each piece of equipment in the chain is frequency locked to a master clock the jitter is dropped at the input.  So if noise can begin from the drive where the music is stored we could make the assumption that a good clock at each device would help minimize noise along the chain.

 

@JohnSwenson or @Superdad do I have this right and can you explain the benefit of chaining USB clocks?  Are we just changing the sound, or is there a benefit from consecutive USB clocks?  If so, then why not a single device with multiple clocks, or is a physical interface necessary?

Those drives pump a bunch of noise on the power lines. This is the reason I keep them out of the microRendu and far away from my system. Having a master clock drive everything has it's issues. I would be concerned about introducing noise from connecting separate devices via all these cables. Not to mention the harm caused by all those connectors. Also, those clocks might not even be the same frequencies.      

[jabbr]

There are diminishing returns to reclocking upstream devices. As long as the jitter is within a defined range, and the setup delay properly set for the receiving latch, the latch will capture on the bit and not during a transition. At this point the receiving clock will determine the phase error.

[Johnseye]

4 hours ago, jabbr said:

There are diminishing returns to reclocking upstream devices. As long as the jitter is within a defined range, and the setup delay properly set for the receiving latch, the latch will capture on the bit and not during a transition. At this point the receiving clock will determine the phase error.

 

If those diminishing returns can be measured with a jitter meter then shouldn't the number of clocks be identifiable?

Furthermore, if the quality of the clock has been managed from as far upstream as the storage device, one would assume any clock based noise or distortion would be managed as much as possible, allowing for downstream components to be less problematic provided they're quality clocks as well. 

[Elberoth]

9 hours ago, Beolab said:

 

This is very interesting to discuss  Alex, and i got two topics for you: 

 

If you elaborate a little with your knowlage and experience on how much better is the  acclaimed 26Nm 1ppm MSB Galaxy clock vs let say the Pulsar / Crystek CCHD595 clocks, and what is the fabrication cost of the Galaxy clock ? Is it the best of the best or could a company like Texas Instruments or Intel make much better for 1/100 of the price? 

 

 

Secondly, what is your thaughts about using a poorer streamer like a BlueSound Node II MQA using two W4s Remedy ( CCHD957 ) SPDIF clocks in a chain with LPS-1 Ultracap vs the top tier streamers like Auralic Aries , Aurrender W20, Antipodes , Sonorus, do you think it is the best result in the end? 

 

My experience is that the Bluesound + 2x clocks is on pair with my other top tier streamers, but i want to know your input on it. 

 

Have an great evening!  

 

/ Fredrik

 

 

What do you mean by 26Nm ?

 

Nm is Newton Metre - unit of torque

 

MSB used to call their clocks by jitter numbers in fs (Femtosecond) - chence models 140, 77 and 33. 

 

It is impossible to compare the MSB jitter numbers to any other oscilators, as for jitter to have any meaning you need to know the bandwith of the measurement.  

 

MSB used to give the phase noise numbers of their clocks on their webpage, which would make the comparo possible, but I cannot find it right now.  

 

[Beolab]

1 hour ago, Elberoth said:

 

 

What do you mean by 26Nm ?

 

Nm is Newton Metre - unit of torque

 

MSB used to call their clocks by jitter numbers in fs (Femtosecond) - chence models 140, 77 and 33. 

 

It is impossible to compare the MSB jitter numbers to any other oscilators, as for jitter to have any meaning you need to know the bandwith of the measurement.  

 

MSB used to give the phase noise numbers of their clocks on their webpage, which would make the comparo possible, but I cannot find it right now.  

 

 

=Nano meter , but forget it 

 

Here you got the Specs in a PDF 

 

http://www.msbtech.com/support/GalaxyClock_Lit_Press3.pdf

[vortecjr]

1 hour ago, Elberoth said:

 

 

What do you mean by 26Nm ?

 

Nm is Newton Metre - unit of torque

 

MSB used to call their clocks by jitter numbers in fs (Femtosecond) - chence models 140, 77 and 33. 

 

It is impossible to compare the MSB jitter numbers to any other oscilators, as for jitter to have any meaning you need to know the bandwith of the measurement.  

 

MSB used to give the phase noise numbers of their clocks on their webpage, which would make the comparo possible, but I cannot find it right now.  

 

The plots from MSB that I have seen are as measured on the analog output of the DAC with a specific power supply. I believe they isolate the signal twice for the measuremeant. Emphasis on a specific power supply. I see a bunch of mods replacing the clock...great. However, the power supply to the clock is usually ignored and I don't mean the power supply to the main board either I mean the power supply to the clock itself. Upgrading the clock on a device without considering the power on the border going directly to it is like putting lipstick on pig. 

 

FYI If you ask Vinnie at MSP about these increasingly better clocks he will tell you that it makes bad CDs sound worse:)

[Elberoth]

40 minutes ago, Beolab said:

 

=Nano meter , but forget it 

 

Here you got the Specs in a PDF 

 

http://www.msbtech.com/support/GalaxyClock_Lit_Press3.pdf

 

Thanks, that was the page I was looking for. The specs for their clock are as follows:

 

FemtoSecond Galaxy Clock Specifications:

Phase Noise at 0.1 Hz -67 db

Phase Noise at 1 Hz -99 db

Phase Noise at 10 Hz -134 db

Phase Noise at 1 kHz -157 db

Phase Noise at 10 kHz* -157 db

Phase Noise at 100 kHz -157 db 

 

If you get me the phase noise figures at the same freq for other oscillator (Crystek or other) I will calculate the jitter for you to make the comparo possible.  

[Elberoth]

 

The plot from MSB is indeed measured on the analog output of the DAC. However, the specific numbers published (the ones I quoted), must have been obtained using a phase noise meter.  

[jabbr]

1 hour ago, vortecjr said:

The plots from MSB that I have seen are as measured on the analog output of the DAC with a specific power supply. I believe they isolate the signal twice for the measuremeant. Emphasis on a specific power supply. I see a bunch of mods replacing the clock...great. However, the power supply to the clock is usually ignored and I don't mean the power supply to the main board either I mean the power supply to the clock itself. Upgrading the clock on a device without considering the power on the border going directly to it is like putting lipstick on pig. 

 

Power supply and rest of circuit absolutely important. Because of the 1/f crossover (a nonlinearity), the flicker noise particularly affects the low end of the phase noise plot (i.e.  -67dBc/Hz @ 0.1Hz) and so 1/f noise in the power supply as well as resistors etc is particularly important. Larger crystals with low imperfections will tend to have less 1/f noise all else being equal.

[bibo01]

2 hours ago, Elberoth said:

 

Thanks, that was the page I was looking for. The specs for their clock are as follows:

 

FemtoSecond Galaxy Clock Specifications:

Phase Noise at 0.1 Hz -67 db

Phase Noise at 1 Hz -99 db

Phase Noise at 10 Hz -134 db

Phase Noise at 1 kHz -157 db

Phase Noise at 10 kHz* -157 db

Phase Noise at 100 kHz -157 db 

 

If you get me the phase noise figures at the same freq for other oscillator (Crystek or other) I will calculate the jitter for you to make the comparo possible.  

It doesn't the carrier though.

The numbers for Pulsar clock you can find them here:

http://www.pulsarclock.com/ds/Pulsar_Clock.pdf

[Elberoth]

40 minutes ago, bibo01 said:

It doesn't the carrier though.

The numbers for Pulsar clock you can find them here:

http://www.pulsarclock.com/ds/Pulsar_Clock.pdf

 

My guess is it is either 44.1 or 48 x 512

[JohnSwenson]

3 hours ago, Elberoth said:

 

Thanks, that was the page I was looking for. The specs for their clock are as follows:

 

FemtoSecond Galaxy Clock Specifications:

Phase Noise at 0.1 Hz -67 db

Phase Noise at 1 Hz -99 db

Phase Noise at 10 Hz -134 db

Phase Noise at 1 kHz -157 db

Phase Noise at 10 kHz* -157 db

Phase Noise at 100 kHz -157 db 

 

If you get me the phase noise figures at the same freq for other oscillator (Crystek or other) I will calculate the jitter for you to make the comparo possible.  

Be very careful with these numbers, they are not directly comparable to any other clock phase noise numbers. Note the numbers are in dB, NOT dBc/Hz which is the standard for phase noise measurements. Looking at that page from MSB it looks like those numbers are from an FFT. Which means this is a sampling of some waveform with some clock. Exactly what is undefined. Did they use the Galaxy clock to sample the analog wave from a DAC? If so is the Galaxy clock also used in the DAC? These unknowns make it very difficult to convert these numbers into meaningful dBc/Hz numbers that can be compared to other clocks.

 

John S.

[Elberoth]

25 minutes ago, JohnSwenson said:

Be very careful with these numbers, they are not directly comparable to any other clock phase noise numbers. Note the numbers are in dB, NOT dBc/Hz which is the standard for phase noise measurements. Looking at that page from MSB it looks like those numbers are from an FFT. Which means this is a sampling of some waveform with some clock. Exactly what is undefined. Did they use the Galaxy clock to sample the analog wave from a DAC? If so is the Galaxy clock also used in the DAC? These unknowns make it very difficult to convert these numbers into meaningful dBc/Hz numbers that can be compared to other clocks.

 

John S.

 

Good point. I have assumed by default that those numbers are in dBc/Hz, which as you said is the standard for phase noise measurements.

[jabbr]

46 minutes ago, Elberoth said:

 

Good point. I have assumed by default that those numbers are in dBc/Hz, which as you said is the standard for phase noise measurements.

I made the same assumption and those numbers aren't out of range for a good low phase noise clock.

[AudioBang]

Not sure if anybody is still out there on this thread - [one year later]...

 

I'm posting my experience upgrading the Crystek CCHD 575 100MHz oscillator [$25] in the Vega DAC to the Pulsar [$425] merely for perspective for anyone interested. Conclusion: In this application, reducing the power supply noise made a significantly bigger improvement over TXCO to OCXO upgrade at 10X the cost.

 

The actual measured phase plot provided with the Pulsar showed a 10dB improvement at 10Hz and 100Hz over the Crystek CCHD-575 generic datasheet published on their website.

Using the Pulsar, the soundstage did snap into another level of focus along with improved transient response. Without all the details about burn in time and listenable improvements,  my immediate thought was that the Crystek 575 is a great clock for $25! I guess that tells you in this case I was not totally WOW'ed for the money.  The improvement was definitely there though.

 

Two years later,  I added a gold Bybee purifier both in line with the ground to the Pulsar as well as in line with the 3.3V Vcc to the Pulsar.

That was when the soundstage really kicked up another two notches. That was a WOW.

I can't speak to the authenticity of marketing mumbo jumbo of Bybee, but in this application, they are definitely removing noise from the supposed Low-noise Pulsar voltage regulator http://www.pulsarclock.com/ds/Pulsar_Power.pdf . If I had to do it over again and I knew what I know now, ideally I'd have inserted the Gold Bybee  purifiers in line with the supply [and ground] to the Crystek.

 

I happened to have these lying around from 15 years ago and they are outrageously expensive today....  Tried them on interconnects and was not impressed.

 

I would really like to know what power supply noise was removed [if even measurable].

I found they work great after a bridge rectifier in a power amp but did not find a WOW in other basic applications. The Krell's I modified had vague soundstages that really opened up after adding the large Gold Bybees after the rectifiers.  

 

Hope this was useful.

 

Rich M

[bibo01]

@AudioBang

Interesting report. I have a Crystek 100 MHz clock in my DAC and I was thinking about a possible Pulsar upgrade.

What low noise PS did you use for it?

[AudioBang]

http://www.pulsarclock.com/ds/Pulsar_Power.pdf

 

ADM7150 CORE - THE 1.7 nV √Hz LDO

 

 

 

 

[bibo01]

3 minutes ago, AudioBang said:

http://www.pulsarclock.com/ds/Pulsar_Power.pdf

 

ADM7150 CORE - THE 1.7 nV √Hz LDO

 

 

 

 

Is it worth considering the LT3045 regulator for it?

[AudioBang]

I wish I could offer assistance but don't have the experience with it.

Honestly, I just went with the Pulsar regulator that they sold with the oscillator.

 

 

 

[AudioBang]

57 minutes ago, bibo01 said:

@AudioBang

Interesting report. I have a Crystek 100 MHz clock in my DAC and I was thinking about a possible Pulsar upgrade.

What low noise PS did you use for it?

Just curious, is your DAC using an ES9018 Sabre or ES9038PRO?

 

On a marketing sheet, ESS states that the 9038 is pin compatible with previous versions [9018] and I was wondering if the 9018 could be swapped for a 9038 PRO without any software considerations....

Just me contemplating more Hi-Fi stupid things to do 

[bibo01]

22 minutes ago, AudioBang said:

Just curious, is your DAC using an ES9018 Sabre or ES9038PRO?

ES9038. It is a LKS Audio DA004 DAC.

In the previous model, DA003 with ES9028 some people changed the master clock to a Pulsar.

I think it is possible - but don't quote me on this - to swap ES9018 to ES9028 because they are not just pin compatible but also output stage can be the same. I believe ES9038 requires higher output.