[cglin222]

some newbie question, so if I connected clock to u18 and i2s to r26, the external is carried via i2s. So it wouldn't be any different if I used u18 internal clock and i2s to r26 and actually connected the clock to the dac r26. Is there any difference

 

[FredA]

some newbie question, so if I connected clock to u18 and i2s to r26, the external is carried via i2s. So it wouldn't be any different if I used u18 internal clock and i2s to r26 and actually connected the clock to the dac r26. Is there any difference

With audio-gd, it is best to use the ext. clock on the dac.

 

[Jake2]

With audio-gd, it is best to use the ext. clock on the dac.

@cglin222 Same is true, from my experience with the R26, irrespective of input or PCM NOS / DSD Direct setting, connecting an external clock to the R26 with a good cable will be more beneficial than instead connecting only to the U18 DDC. It is beneficial to clock both devices if you have an external clock with two outputs but I’d use your best cable on the R26.

This is actually a complicated space where results and preferences with the Gustard *26 DACs seem to vary a little from user to user and are the product of a number of factors - the I2S data spec, yes, but also Gustard’s K2 clock synthesiser implementation including how/whether an external clock signal via the R26 10mhz BNC input is used for different inputs and NOS/DSD settings, and the quality of your cables for and between all devices (I2S, clock, power). I say this as I prefer the R26 LAN input, internal renderer to the U18 > R26 via I2S, even when both are externally clocked. Though the difference widens or narrows depending on I2S, USB & PC cables used. Suspect a Tubulus I2S might achieve parity or better.

My advice, experiment as I’ve done and run with what sounds best in your system.

 

[MartinWT]

some newbie question, so if I connected clock to u18 and i2s to r26, the external is carried via i2s. So it wouldn't be any different if I used u18 internal clock and i2s to r26 and actually connected the clock to the dac r26. Is there any difference

I can only strictly comment about the U18 / X26 Pro. The external clock is connected to the U18 where the clock is carried through the I2S cable to the X26 Pro. That way, both benefit from the clock which uses only one connection. I have tried various configurations and this one sounds best.

Note: this does NOT work with any other DDC / DAC connection such as AES.

 

[ray12345]

I can only strictly comment about the U18 / X26 Pro. The external clock is connected to the U18 where the clock is carried through the I2S cable to the X26 Pro. That way, both benefit from the clock which uses only one connection. I have tried various configurations and this one sounds best.

Note: this does NOT work with any other DDC / DAC connection such as AES.

I am on U18 and X26 Pro as well, and I previously also used only one clock cable to connect to U18, as dealer said clock will carry over to X26 Pro via I2S.

Then one day, I tried connecting clock to both U18 and X26 Pro, never looked back, the holographic sound stage and transparency goes up one whole notch, try it.

One additional benefit in doing this, you can mix and match different cables and fine tune the sound to your taste. I used Cybershaft cable from clock to U18 and then Harmonic Tech from clock to DAC.

 

[Thetaburn]

I am on U18 and X26 Pro as well, and I previously also used only one clock cable to connect to U18, as dealer said clock will carry over to X26 Pro via I2S.

Then one day, I tried connecting clock to both U18 and X26 Pro, never looked back, the holographic sound stage and transparency goes up one whole notch, try it.

One additional benefit in doing this, you can mix and match different cables and fine tune the sound to your taste. I used Cybershaft cable from clock to U18 and then Harmonic Tech from clock to DAC.

Interesting.
Having only the U18 connected with the Ock2 sounded fine but I also preferred the U18 and x26pro connected.

I connect the Harmonic Tech cable from clock to U18 and LMR 400 from clock to x26pro.

I will try to switch them later and see if there is a difference in sound.

 

[ray12345]

Interesting.
Having only the U18 connected with the Ock2 sounded fine but I also preferred the U18 and x26pro connected.

I connect the Harmonic Tech cable from clock to U18 and LMR 400 from clock to x26pro.

I will try to switch them later and see if there is a difference in sound.

I tried LMR400 as well, it has some sound character of its own, it tends to be making the sound seem more high end at first, but on further audition one will find out it changes tones of some music instruments.

On my system, I much prefer Cybershaft to U18 and Harmonic Tech to X26 Pro.

 

[MartinWT]

so if I connected clock to u18 and i2s to r26, the external is carried via i2s. So it wouldn't be any different if I used u18 internal clock and i2s to r26 and actually connected the clock to the dac r26. Is there any difference

Yes, there would be a difference. The U18 would not benefit from the external clock.

 

[cglin222]

Yes, there would be a difference. The U18 would not benefit from the external clock.

Well I mean the external clock that passed to dac via i2s vs clock input on the dac
To me isn’t that the same clock just passed via i2s vs directly input on the dac but still have u18 i2s to dac

 

[MartinWT]

Well I mean the external clock that passed to dac via i2s vs clock input on the dac
To me isn’t that the same clock just passed via i2s vs directly input on the dac but still have u18 i2s to dac

I think I understand what you're saying and no, I don't think the I2S clock signal would pass back to the U18 from the DAC. Therefore the U18 would be running on internal clock which would degrade its performance.

By connecting the clock to the U18, it is passed from U18 to DAC and therefore benefits both. I know some experiences vary here, but I have tried connecting my clock to the DAC as well as the U18, and it makes no difference as the clock coming via I2S appears to override it.

 

[Jake2]

@cglin222 see I told ya prefences vary even by folk with very similar gear!

So one tweak I’m going to try this evening which I've read good things about over in Martin's TAS forum (credit to @Stellabagpuss IIRC) is replacing the R26's internal 3-4" MCX jack - BNC socket pigtail cable (from the board to the BNC socket on the back of the R26) with this Amphenol MCX jack/BNC socket adaptor. So the only cable in play to the R26 board on which rhe K2 clock synthesiser sits will be my Harmonic Tech DC III. I intend to do the copper foil tape wrap thing too around the BNC junction.

Will keep you posted.

My main concern is lateral stress on the circuit board especially if the cable was inadvertently pulled hard. Will see how much I can mitigate this.

No idea what the internal terminations of the 10Mhz external clock connection are on the X26 Pro or A26 are but if the same it may be applicable there too.

https://nz.mouser.com/ProductDetail/Amphenol-RF/242204?qs=ZSAEa/Ml32x2uH1lGKT3wA==

 

[kiwibirch]

Review of the Premium 10MHz Master Clock Generator: LHY OCK-2

Master clocks has been the heartbeat in the Recordning Studio field for many years now. It was when the Digital technique was intruduced the technicians found that the oscillator quality direct affect the sound result. 75 Ohm impedance was chosen for the BNC (connectors and cables). 75 Ohm impedance is a common choice for impedance for digtal transfer in both the studios and also in the consumer products (SP/DIF). In the studios a need for longer distances of digital transfers between equipment is also done with balance signal of 110 Ohm (AES/EBU with XLR-connectors). A remark. MUTEC has its roots in the recording industry.

In the High End part of the HiFi community the master clocks have had a place for some years now but lately the great benefits of using a good master clock also has hit the HiFi in the less astronomic priced equipments. Ex. Audio-gd, Gustard.. In the consumer market an impedance of 50 Ohm is often used.

Exemples of the "heavier" brands of excellent master clocks are Mutec, Cybershaft, AfterDark and a few proprietary brands that are very expensive but not performs very good compared to the three earlier named here.


LHY OCK-1
For those who not know the LHY OCK-1, I can explain that it is a rather new, rather simple design with all the parts in one compartment. Its power is EMI-filtered, then a "naked" toroid transformer produces the lower voltages for the rectifiers, a couple of filtering capacitors from Nichicon/Wima. The filtered DC then fine regulates through two LT1963A for the OCXO with a spec of -110 dBC/1Hz(!). Three BNC outputs with an impedance of 50 Ohm (one with Square wave and two with Sine wave). All three outputs has their own buffer to minimize interference between them.
I bought this one on Aliexpress with a good discount. The LHY OCK-1 is doing a very nice job and is a baragin as it comes. It gives a very nice sound with a "wealthy bass"
as I wrote in an earlier post. I think a part of its "rich" bass is caused by its naked toroid transformer. It is rather common that You will get an lightly emphased bass with
them.


Transformers
About transformers. Toroids are very effective but has to be oversized to not run too hot/warm because they have a
hard time to get rid of its heat if pressured. C-core and R-cores are a bit less effective but can handle the heat emmission better with their better coupling between "Core to air" (=more exposed core surface to air). E-I core transformers are easy to build but produces an unnessesary big magnetic field around itself. Has to be shielded if used in these small signal applications.

As I wrote I bought the OCK-1 and it exceeded my expectations big time. For its price (USD350 in my case w. good discounts) it is a home run and it is much better than the Oscilloquartz (-90dBc/1Hz) it replaced. I can absolutely recommend the LHY OCK-1! It is almost surrealistic that a <-110dBc/1Hz OCXO is sold for around USD400-450. Gustard sells the C18 for USD1599.


LHY OCK-2
So we are now looking at the LHY OCK-2. Based on the very good experience with the LHY OCK-1 I couldn't resist to order the LHY OCK-2 when it was announced. I got it the 25'th of November and it is running with power on since. The LHY OCK-2 is a completely different animal compared to the OCK-1. The OCK-2 has been refined in every aspect. First the aluminum box itself. It is produced with CNC-milling machines from a solid block. The finnished box has three separated compartments which holds:

1. Power input/fuse, EMI-filter, UK made Talema transformer, two sets of very fast diodes for rectifications, first stage filtering (Capacitors). =>

2. Second stage filtering and voltage regulation with three independent LT3042's with PNP's (PNP transistors are added to rise the current) =>

3. Correct voltage of excellent quality for the OCXO (<-115dBc/Hz). A fine tuning of the output frequency(don't touch!). Six BNC outputs with three with Square wave and the other three with sine wave.
All the six BNC output have dip-switches with choice for 50 and 75 Ohm impedance and also dip switches for a choice to be connected or disconnected to GND (or ISO). In ISO-mode the receiving of time pulse device(s) GND is/are valid. All outputs also have independent buffers also in this OCK-2.

All these efforts added into the OCK-2 makes all the difference. The LHY OCK-2 is sold as a "Premium 10MHz Master Clock Generator" and it is completey true. I had no idea of how a <-115dBC71Hz OCXO could perform. Now I know.

Testing equipment used
I have tested to feed Audio-GD DI20HE (DDC/reclocker) + R7HE Mk2 (R2R dac), Gustard U18 (DDC) + R26 (R2R dac) and finally a Mutec MC3+USB (modded. Switched PSU trashed, now with an Ultra silent linear PSU). The Speaker rig is based on Audio-gd's Master Power amps. (Master 3+ 2 x Master 2's) and the HE1 as preamp. Speakers are Quad ESL-63's with Gradient dipole basses, SW-63's. Cables used are decent priced. A very transparent, high performing and revealing rig.

The OCK-1 give a cosy, warm feeling and I personally think that this sound charactar will make most music lovers happy. It will fill Your listening room/headphones with a pleasant, laid back, detailed sound. A soft yet detailed mid an highs and a warm rich bass as foundation. A very easy to like sound that also is a bit forgiving.

The Mutec REF10 SE120 is an expensive Master clock with all the qualities You could ask for. The sound is calm, the scene is wide, deep and high. Airy with very precise placing of instruments. Microdetails are easy to spot, even the tiniest, weakest sounds as a light cough from someone far back in the audience, or a turning of note page somewhere in the orchestra. The Mutec REF10 SE120 reveals it all. Not forgiving at all on less good recordings, but fabulouse on great ones.

LHY OCK-2
So the LHY OCK-2. -How does it perform?
A fast discovery is how much the quality of the PSU parts is affecting the sound result. Known from earlier experiencies is that the "PSU is equal important as the OCXO itself". Meaning: You can ruin the performance of a OCXO with a low phase noise with a less ambitious PSU/internal shielding.
I can tell You that the LHY OCK-2 is more close to the Mutec REF10 SE120 than to the "Cool Cat" the LHY OCK-1. The precision in all the PSU stages in the OCK-2 along with its internal shielding is key I think.

The sound given with the LHY OCK-2 is less bassy or "a bit thinner" compared to the OCK-1. This is because of its all through higher precision in the design of the OCK-2 and choice of the higher quality of components combined. The sound is true and the bass isn't absent, it is just very precise. I have tried both GND and ISO and in my context and there is no audible difference in sound, which is of very high quality on both square and sine wave.

Summary.
The LHY OCK-2 is far better/different OCXO than the OCK1. The OCK-2 has a Hi End impact on the sound. It is for us the more demanding music listeners who want to have the full registre precision. The OCK-2 is just irresistable if You are on a clock hunt and this with Hi End-ambitions. I didn't think this performance was possible to get for less than USD3000. And with multiple outputs and the 50/75 Ohm of impedance chioces, it is almost unreal. The price asked for the LHY OCK-2, of USD749, is a bargain. No doubt. The competition is 4 to 6 times higher priced for the same level of performance.This LHY OCK-2 is up on the doorstep to the High End market.

I think that both these LHY OCK-x Master clocks will shake the market with these values of price/performance. They most likely will sell very well. I will keep mine for sure.

Advices.
If You are a critical music listener, (as I am) the LHY OCK-2 is the right/better choice for You.
If You are listening to pop/rock/electronica/background music, games, I think the LHY OCK-1 is the better choice.

I hope You are somewhat helped with this short review

Finally.
I bought my LHY OCK-2 from https://www.beatechnik.com/ and Alvin gave me a very positive response when I contacted him. I asked for a relevant Phase Noise plot for the LHY OCK-2. I hope it will sent to me in a short while so I can post it here.
Anyway, I ended up ordering the LHY SW-8 switch aswell. I like the build and the OCXO conducting the ethernet traffic to my streamers. Thanks Alvin.

Edit.
I have intentionally not touched the jitter aspect in the review because I don't have the equipment to measure it but a firm and clear texture in the bass registre can usually be explained with a measurement of a lower jitter level. (Jitter is irregularties in the digital domain causing audible distorsion in the analog domain) Maybe we can get a plot or a number also of the jitter level in the OCK-2 from Alvin.

Edit. 2022-12-07. Alvin was kind enough to send me a few pictures from their quality testing (on each) OCK-2 master clock before delivery. As You can see, the measurements are good. Not much ringing on the first "knee" in the square wave. Good Measurements. Still waiting for a Phase Noise plot for the OCK-2.

/Jan

DId you ever get Phase Noise plots or measurements for the OCK-2?

 

[Jake2]

DId you ever get Phase Noise plots or measurements for the OCK-2?

Not from LHY, no. Nor has anyone else published any phase noise plots of the OCK-2. I wonder if we could persuade the OP to create a sticky for this and other oft asked questions, and debated points, in their original post. (Given he last visited HF over 6 months ago I’m not holding my breath…)

Regarding the lack of measurements for the LHY OCK OCXO's I wrote to Jay's Audio the 29'th of April:

Me: Message: -Hello, I have very good experience with Your LHY OCK-1 and OCK-2 master clock generators and also the SW-8 switch. The lack of phase noise graphs for the clocks has started to work in a negative way for the LHY brand. The gears are good, no doubt but on forums LHY gets a bashing because of this. I am sorry but You could easily mend this/recover the reputation and confidence for the brand with a few representative measurements for the OCK-2, OCK-1 and maybe also for the SW-8 and SW-10. Thank You. Jan M

I got their answer a month later (28'th of May):

Hi Jan,

It's really great to hear from you, and I genuinely hope this message finds you in good spirits. My name is Weng Fai, and I am the Sales & Technical Manager here at Beatechnik. First and foremost, I want to extend my sincerest apologies for the delay in responding to your message. We truly value your time and understand that we should have been more prompt in addressing your concerns. I'm sorry for any inconvenience this may have caused.

I want to express my heartfelt gratitude for sharing your valuable feedback regarding the importance of measurements. Your insights are incredibly valuable to us as we strive to continually improve our products and services. We understand the significance of objective measurements and specifications in determining equipment performance, and we acknowledge that they provide customers like you with a valuable reference point.

However, I must inform you that at the moment, we do not conduct individual measurements or provide certificates for each OCK/SW unit we ship. This decision has been influenced by various factors, including the current price point of our products. We want to ensure that our offerings remain competitive and accessible to a wide range of customers. Conducting individual measurements for each unit would require significant resources, both in terms of specialized equipment and skilled personnel, which would inevitably increase the cost significantly.

That being said, I want to assure you that we have dedicated a tremendous amount of time and effort to fine-tune and extensively test the OCK against competitor Master Clocks rated at -105dBc/Hz to -118dBc/Hz. Our talented engineers have poured their expertise and passion into ensuring that the LHY Audio OCK delivers exceptional performance. We truly believe that it stands strong on its own merits, and we have full confidence in its abilities.

I wholeheartedly understand that sound perception is highly subjective, and what may sound incredible to one person may not resonate as strongly with another. That's why we put so much emphasis on customer feedback and real-world experiences. Your comments and insights are invaluable to us as we continue to refine and enhance our products.

Once again, I want to express my deepest gratitude for taking the time to share your thoughts and concerns with us. Your feedback serves as a constant reminder of the importance of our work and the responsibility we have towards our customers. If you have any further questions or need any assistance, please don't hesitate to reach out. We are here to help in any way we can.

Wishing you a truly wonderful day ahead!

Many thanks.

Best regard,
Weng F
-------

So there You have it. After all the fuzz I thought I should let You know what is said in this matter.
/J

 

[FredA]

This is a plot of an ock1 sample i received from Beatechnik before the ock-2 was released. The ock-1 was said to have 110@1hz guaranteed. - 116db for the ock2 when released.

 

[joenetic]

Anyone know if I keep the oxco turn on all days, will cause the frequency drift after some times of operation? Or I should turn it off when I don't use it?