A novel way to massively improve the SQ of computer audio streaming

[zephyr24069]

8 hours ago, auricgoldfinger said:

 

Thanks for your thoughts.  I've done a little reading, and it seems that 75 ohm is the best approach for high end audio and video.

I'm not sure what this is based upon...75-ohm may be the more common approach but 50-ohm is also a very valid approach in high end applications.  Further testament to this is Esoteric's centering this top-end products on having both 50-ohm 10 mHz master clocking capability as well as 75-ohm reclocking based approaches.

 

Apologies for delayed replies; I'm not on the forums all that much. Any specific questions,...ping me via IM and I jump in.

[zephyr24069]

6 hours ago, dgarretson said:

 

Cybershaft seems like a good choice.  There is an Audiogon thread in which a few guys with high end DACs reported excellent performance and good customer service at Cybershaft.  IIRC the Cybershaft seller packages a used Rubidium core with his own power supply and chassis.  I'm not sure about the lifespan of a rubidium core, but they do need to be factory recalibrated once and awhile.

Yes,...definitely; I'm one of them. You can find more details on Agon as well as WBF and Aficionado (AA).    There are quite a few users out there now.  The OCXO side of the dual clock or the OCXO-only units are my favorite for musical playback; they have superior low phase noise and harmonic distortion characteristics (which BTW the former is part of the calc for how much/little jitter a unit introduces...) over Rubidium implementations despite their parts-per-billion precision specs. (IMHO).    I've evaluated SRS, Antelope and other clocks and prefer the Cybershaft for price and performance.  It's phase noise and effective low-jitter specs are superior to others if you dig in far enough.   The only clock I have not tried is the new Esoteric Grandioso G1 and the DCS clocks as I don't have a DCS stack.  FWIW,..I know several Esoteric and DCS system owners that utilize a Cybershaft 10 mHz master clock as a baseline for their Esoteric and DCS clocks themselves with fantastic results....

[zephyr24069]

2 hours ago, dgarretson said:

One thing I like about the SRS rubidium master clock and the Antelope LiveClock distributor is their ability to accept external 12Vdc power.  I've been using a Hynes SR7 for this.  It does make an improvement relative to the stock SMPSs, and should be a consideration for comparisons at the high end.

Good point,...if you are going to have a unit that takes external 12v power, it is best to use a bespoke audio-grade power supply.

In the case of the Cybershaft, the PS is internal but uses a Schottky Barrier diode-enable power supply in their best units.

[zephyr24069]

15 minutes ago, austinpop said:

Just a quick teaser on my next area of exploration.

 

I've had my eye on the Cybershaft reference clock, ever since @hols wrote about it. I also got @zephyr24069's help and advice. He put me in touch with Kenji at Cybershaft, from whom I learned that their entire production run was sold out, and there was no ETA on a new product with the quality of the OP-14.

 

Well, my luck has turned. I was able to locate an OP-14, and it has been shipped to me. My intent is to use this as a reference clock for my trifecta, feeding the single 50 ohm master clock input of my tX-USBultra.

 

Just to set the context, the OP-14 is a curated unit, where the OCXO has been measured to have a 1Hz phase noise of -114.0 to -114.9 dBc/Hz. The Ref 10, by contrast, is even better, with a claimed phase noise of ≤  -116 dBc/Hz at 1Hz. But at a third of the cost used, the OP-14 seems like a promising option.

 

Once I have my findings, I will report back. 

Congratulations...very glad to hear you found an OP14 level Cybershaft! Send me a PM and let me know details....

[zephyr24069]

9 hours ago, rickca said:

It's great that you've been able to source one.  Cybershaft sounds like a great name for some DPRK malware.

In my experience Cybershaft is a great company with an owner that that goes out of his/their way to build great products for users at a reasonable price.  

 

The DPRK is something else entirely....

[zephyr24069]

3 hours ago, hurka said:

Morion ocxo MV341phase noise of <-120 dBc/Hz at 1 Hz and <-146 dBc/Hz at 10 Hz.

http://www.microwavejournal.com/articles/print/26279-precision-low-phase-noise-low-adev-ocxo-mv341

https://item.taobao.com/item.htm?spm=a1z10.1-c.w4004-10262758976.16.437407835c0R9Z&id=528552934348

Great specs for phase noise and great Allen performance; are you including this as you plan to build the sub-assembly shown and use it in your system?   If so, it would great to hear more details,...power supply that will be involved, etc..and any testing of the finished product in your system.  Thanks for posting this!

[zephyr24069]

Yes, English is my native language.  I saw your posted joke and was making a comment, nothing more.

[zephyr24069]

3 hours ago, austinpop said:

 

Yes indeed! Waiting for his Paul Hynes SR7 to come in as well, and then we'll have a lot to dig into.

We love details and pictures!  Good luck with all of your upgrades!!!

[zephyr24069]

On 9/13/2017 at 9:17 PM, hurka said:

This time just the plan,but I have some U caps board 16v(max) 20F 6pcs fed my atx mobo before,i think this is the finest psu in this (50-50.000$)range

Thanks for the details,..best of luck with all those mods!

[zephyr24069]

7 hours ago, austinpop said:

Listening Impression with the Cybershaft OP-14 Reference Clock - Part 2

 

Since my clock chain is hard to visualize from what's in my signature, I've updated my system topology picture to give you a clearer idea of how things wire together. Hopefully, it helps understand the flow better. See the diagram below.

 

 

And here is a photo of the latest "spaghetti chain." I would characterize this more as a pasta medley - a hearty mix of linguine, pappardelle, and penne.

 

 

I've been doing a lot of listening since my Cybershaft arrived. However, I waited (im)patiently until about 50 hours of burn-in, and then again at 100 hours, to do any comparisons, or draw any conclusions.

 

Roy tells me that on his Ref 10, it is easy to turn each clock output on/off, which makes A/B comparisons of with/without reference clock really easy. On the OP-14, there is no switch. Also, it's important not to power cycle the unit, as it can take at least an hour for the OCXO to stabilize. The tX-USBultra continues to function if the reference clock is hot plugged in or out. My technique was to disconnect and reconnect on the OP-14 output, as it was easy to reach from my listening chair.

 

The first time I did this, I went from ref clock connected to disconnected. It took my brain a few seconds to register, but then it hit me. WOW - what a difference! It was like deflating a balloon. Some of the magic died. And yet - this was what, just a few days ago, I thought was the best my system had ever sounded. Connect the OP-14 back, and the goosebumps were back!

 

How to describe the improvement with the OP-14? I'll talk about it in the context of these pieces of music I happened to use while comparing:

• Mahler Symphony 3: Sehr langsam "O Mensch"
   
•  Sibelius Symphony 6: 1st movement
   
• Buena Vista Social Club: Pueblo Nuevo
   
• Mahler Symphony 5: Scherzo
   
•  Gorecki Symphony 3: 1st movement
   
• Beethoven Piano Concerto No.5 "Emperor": 1st movement

 

The improvement comes in these major areas:

1. Rock solid image
   • The sonic image seemed bigger in all 3 dimensions, but also had a sense of solidity and stability to it.
   • This was especially noticeable in the big orchestral Mahler and SIbelius pieces
2. Dynamic
   • It seemed like the music had a greater dynamic range.
   • There was a perceived reduction in the noise floor.
   • In the Mahler 3rd, the movement begins with an extremely low level harmony in the strings. I'd never heard this so clearly and so dramatically before.
3. Dimensionality of individual instruments
   • In Pueblo Nuevo, the piano sounded more real than before
   • Ditto in the Beethoven piano concerto
4. Incredible resolution and detail
   • What I love about the Mahler pieces in my list is how small groupings of instruments play with and against each other to really bring out the emotion. In sonic terms, it allows individual instruments to shine. With the OP-14, these instruments - like the french horn, the oboe, the strings had incredible texture and dimension.
5. Improved bass
   • The Gorecki starts with a minimalist melody in the double basses and cellos. With the OP-14, I really felt the growl in the pit of your stomach.
6. Smoother tonality
   • Overall, there was a further reduction in harshness, brightness, and fatigue. There was a richness, a smoothness, and an incredible sense of ease.

 

Just when I thought my trifecta couldn't sound any better, along comes another improvement that raises the bar further. I am just gobsmacked by the sheer magnitude of this improvement. And all this without any change to my DAC. Frankly, after the last round of improvements, I was pretty convinced that to achieve significant gains past this point, I'd have to upgrade my DAC first. But the Codex keeps scaling up to reach new heights. Pretty darn impressive.

 

And finally, a word about cost benefit. The OP-14 isn't cheap, so is the incremental benefit worth the cost? For me, the answer is yes, because of two reasons:

1. I find it difficult to go back to the prior configuration without feeling a sense of profound loss.
2. The SQ jump with the OP-14 is much greater than what I heard when I replaced the Codex with the DAVE in an earlier listening session. That price delta was HUGE, much higher than the price of the OP-14.

Clearly, in my system, the investments in the front end of the digital chain seem to pay bigger dividends in SQ than just in the DAC. Eventually, I'm sure everything matters, but at this point, I feel like the investment in the OP-14 is giving me excellent value.

 

As always - every system is different, so YMMV!

Great post with a lot of detail!  Your listed points parallel with what I've heard out of an OP14 level curated unit from Cybershaft with my Esoteric stack and are also what I'm hearing with my new Cybershaft OPxx curated unit that was custom-build with several features that may make it into other units in the future. The improvements are extremely noticeable and when I remove the clock from the circuit, my experience is the same, i.e. that I miss it dearly and the transformation low-phase noise OCXO 10 mHz clocking brings to my system.  These clocks effectively upgrade my transport-DAC combo "in place" and allow everything to achieve its full potential. As you say,...YMMV; this has been a very interesting trip to say the least!

[zephyr24069]

On 10/21/2017 at 5:57 PM, austinpop said:

Another intriguing master reference clock:

https://www.computeraudiophile.com/forums/topic/37332-teac-10mhz-clock-cg-10m/

 

BTW - the trolls are already crawling over that thread, so suggest we discuss it here.

 

I don't know how to compare the specs "High accuracy specifications with frequency temperature characteristics within +/- 3 ppb and frequency accuracy within ± 0.1 ppm" with the phase noise specs of the Ref 10 and Cybershaft.

 

If anyone knows how to do the conversion, please educate us. @zephyr24069 , your thoughts?

Apologies for the late replies here and elsewhere on the forum!

 

Temperature variation is the enemy of quartz and other crystals when used for frequency generation.  This pervades the master clocking topic as well as other areas that utilize crystals, particularly quartz as an oscillator; this is even true in watches. The highest quality watches with quartz crystals have often included some means of temperature dissipation/stabilization so that the watch works correctly regardless of the weather/temperature, on-body/off-body, etc...

 

I am not aware of any way to specifically convert the temperature accuracy numbers above to frequency accuracy but am sure that the frequency accuracy/stability of the CXO or OCXO module in question is influenced in part by the temperature stability.  

 

[zephyr24069]

On 11/6/2017 at 6:34 PM, austinpop said:

Clock Distribution and Termination

 

I wanted to update this thread with some information I have gleaned from recent discussions with Kenji Hasegawa-san of Cybershaft, May from SOtM, as well as @zephyr24069, who has provided me very valuable advice with regards to clocks.

 

Important Considerations with Clock Distribution

 

With all the interest in the SOtM sCLK-EX and master reference clocks, it's important not to lost sight of the basic tenets of clock distribution. At the frequencies of interest here, in the 10-54 MHz range, a clock cable acts as a transmission line. Transmission lines are defined by their characteristic impedance. For the SOtM, Mutec, and Cybershaft being discussed here, they are designed to use cables with 50 or 75 ohm characteristic impedance. It is also necessary for clock cables to be terminated at both ends, with the correct impedance (50 or 75 ohm). Proper termination is necessary to minimize reflections, which occurs on the transmission line if there is an impedance mismatch.

 

Point to Point

 

We have almost exclusively been discussing point to point clock connections in this thread. Examples of this are:

1. Cybershaft clock <-> tX-USBultra master clock input via 50 ohm BNC
2. Mutec Ref 10 <-> Mutec MC-3+ USB via 75 ohm BNC
3. sCLK-EX clock point <-> modded component (switch, router, sMS-200, etc) via 50 ohm SMB

In all these cases, it's important to know that the source and target connections are internally terminated. In scenario 1, for example, the Cybershaft output is terminated with a 50 ohm impedance, as is the master clock input of the tX-USBultra. I have confirmed this with both Cybershaft and SOtM. The Mutec Ref 10 uses an internal distribution amp to provide 8 independent clock outputs, but each of these is internally terminated, and expects a properly terminated target as well.

 

In case you are wondering, SOtM handles the termination internally when you send them components to mod. For each sCLK-EX clock point, both the source and the target are appropriately terminated.

 

But what about the case, where you're a cheapskate like me, who doesn't want to spring for multi-output clocks like the Ref 10 or the upcoming SOtM sMS-OCX10? Can I use a single high-quality clock like the OP-14 and drive multiple outputs?

 

This is where things get interesting.

 

Daisy Chaining

 

Yes, you can daisy chain, but you have to consider the entire length of the cable across the chain as a single transmission line, and you must have termination on each end equal to the characteristic impedance of the cable. For this to work, you have to have devices whose inputs can be selectively configured to be terminated (i.e. have an input impedance of 50 or 75 ohms as needed), or unterminated, in which case the input impedance of the input is very high. In the quote from Kenji below, he calls this "Hi-Z."

 

Regarding distribution of clock T plugs, it is possible under certain conditions.

For example, in the case of a daisy chain

 

1.

Clock output(50ohm) ------T--------T--------T-(50ohm)Terminator

                                      (Hi-z)   (Hi-z)    (Hiz)

                               Device1   Device2   Device3

2.

Clock output(50ohm) ------T--------T- non

                                     (Hi-z)   (50ohm) 

                                  Device1   Device2 

 

( Hi-z = High impedance) 

Be sure to have one 50 ohm impedance at the end and the other relay point must be Hi-z.

Therefore, T plug can be used only when the clock input can be set to Hi-z.

For reference, I attach a connection diagram of CH presision CH and D1. Please be aware that each relay point is Hi-z.

If, for example, there are 50 ohm points in two places, the impedance will be 25 ohm, the current will overload and destroy the output circuit of clock due to long-term use.

SOtM tX - USBultra can not set the input impedance to Hi - z. So SOtM tX - USBultra does not use T plug in the situation.

Also, due to the use of T plugs, noises of each device can interfere and clocks that can be transmitted can not be transmitted. I do not recommend using T plug.

The best way to distribute the clock is to use an ultralow noise distribution amplifier.

However, I could not find a low-cost ultra low noise distribution amplifier of less than $ 1000 from the world market.

We are developing to sell low-cost distributors by next spring.

 

Pay particular note to his point about overloading the output circuit of the clock due to it "seeing" a lower impedance than designed. The second consequence of not paying careful attention to termination is that impedance mismatches cause reflections, that degrade the signal integrity of the clock, which negates the whole point in the first place.

 

The other point to note is that he discourages the use of daisy chaining, and promotes the use of an ultra low noise distribution amplifier. I got the same feedback from May and I believe (although I'd have to check) Mutec also discourages daisy chaining. With the Ref 10, it's self evident due to the provision of 8 clock outputs!

 

So what does this all mean

1. Don't daisy chain, if at all possible. Even without the other complications, daisy chains necessitate longer cable lengths, which degrades clock quality
2. If you must, design your chain to ensure that all devices in the chain can be configured to be unterminated, and that there is proper termination of the right impedance on both ends, using tees and terminators.
3. At least for the SOtM Ultra components, SOtM does not currently provide a way to switch between terminated and unterminated. I'm pretty sure that upon request, they can configure a device whichever way you want it.

For me, this means that if I get to the point where I have more than one component with a master clock input that I want to drive, I'll want to spring for a Ref 10 or OCX-10. Ouch!

Excellent write-up!!!

[zephyr24069]

On 2/13/2018 at 11:24 PM, austinpop said:

 

I did hear back. Yes, he plans to offer a stand-alone signal distributor. That chassis will be the same size as OP14.

 

Beyond that no further details, but hopefully we will learn more in the next 2-3 months.

That's consistent with what I am hearing as well but no details yet...very eager to hear what this is all about!

 

[zephyr24069]

1 minute ago, zephyr24069 said:

 

That's consistent with what I am hearing as well but no details yet...very eager to hear what this is all about!