[mgsu]

I like your thought process but I doubt if adding a external clock changes the situation. One of the characteristics of I2S is that it runs as master (in my set-up DDC) / slave (in my set-up DAC). One of the advantages of I2S is the single master device so there is no issue with data synchronization. Why would a designer circumnavigate one of its advantages and add complexity into its design by eliminating one of the selected protocol its advantages?

For other connections like SPDIF and Toslink synching makes sense as they do not have a master slave design. Taking the TEAC UD-701n as an example: when you add an external clock you have specify if the source via SPDIF or Toslink is connected to the external clock as well as it will than sync. It also says that for USB ad LAN connections it does not matter as the UD-701n will re-clock it.

I agree,
Since the i2s was intended as a protocol for signal transmission between microchips and was later adopted as a connection between devices that carries the data signal and clock signal separately, it would not make sense to reclock the clock signal again by the DAC.

 

[OCC7N]

Great info. So this means different vendors take a different approach in their I2S design and implementation and explains why their is no standardized pin layout yet for I2S.

To me this I2S clock info will be an new qualifier to look at when selecting equipment.

[speculation mode: on]
Please allow me to speculate a bit (and please ignore the bit below if you believe this is not adding any value)

I2S runs in a master slave set up. There can only be one master but there can be multiple slaves. When there are multiple slaves is is called an I2S network.

In an I2S setup the master can be sending device (DDC for example) or the receiving device (DAC for example). However there is a third possibility and that is that an external controller is the master (and in this example both the DDC and DAC becomes slave).

How cool would it be if Audio GD in their I2S design architecture planning for this and developing and external controller with a super precise Clock. That would be a nica addition to their product line.

Note: I have no knowledge of Audio GD's roadmap or design plans or other info other that what is out on the open, so please read this speculation part with a healthy dosis of skeptics and thus with a grain of salt.

[speculation mode of]

I know im not placeboing here but after updating the firmware to receive clock input on the R8HEMK2 I noticed a blacker background, and a cleaner rytmhic playback

 

[mgsu]

I am curious if you set the R26 to use the external clock? It will use the external clock when set to despite being connected via I2S. At least it does with my X26Pro connected I2S from a U18. I suspect the R26 does too. If set to use the ext clock, I find it difficult to believe you would not hear a difference with a OCK-2. An OCK-1 made a very nice difference with my X26Pro+U18 combo with both set to use the OCK-1.

I am glad you hear a difference. I am not disagreeing or trying to convince you people that there is no difference. just saying that with my setup there is no difference audible.

Maybe i would hear a difference when i change my SU-6 to a DI20HE because the SU-6 cant take master clock signals.
Clocking the R26 and the SOTM switch alone without the DDC there is no difference audible.

Edit:
I have gone full retard with power filtering, Niagara 3000, Hypsos, Silent Angel which brought a lot of improvements to my system.

If you like to experience a 10-20% improvement on your DAC then go with a Puritan or Niagara power filter.

 

[Flyblues]

So you are saying this goes for every ddc and dac. If i2s is used with clock to both dd and dac wont improve on the dac part?

It will improve the DAC part by taking the improved Clock signal fed by its master (DDC in example) in stead of an additional connection from the Clock direct to the DAC.

Audio GD seems to be an exception to this, please see the post from @FredA above.

 

[OCC7N]

It will improve the DAC part by taking the improved Clock signal fed by its master (DDC in example) in stead of an additional connection from the Clock direct to the DAC.

Audio GD seems to be an exception to this, please see the post from @FredA above.

Ok, because I instantly heard differences on the square output from ock2 into dac after I was only running ddc first.

Well Both were also set to ext. The dot(.) indicates it receives clock on both dac and ddc on there individual 10Mhz input

 

[sajunky]

I agree,
Since the i2s was intended as a protocol for signal transmission between microchips and was later adopted as a connection between devices that carries the data signal and clock signal separately, it would not make sense to reclock the clock signal again by the DAC.

It depends. Inter-chip connection do not require reclocking as traces are uniform/very short and a PCB wide ground plane creates an uniform voltage reference. These conditions are not met where we have two different devices, power supplies, lenght of the cable exceeds interchip values. It is why in general reclocking is recommended.

In this situation reclocking can be avoided only if both devices are synchronised to the same frequency. It is why we have 10MHz external clock input. If Gustard does otherwise (do not do reclocking or do not synchronise to the external clock when enabled), they are wrong.

 

[MartinWT]

Gustard was kind enough to respond and their answer was unambiguous: The A26 uses the U18's clock when connected over I2S.

Thank you for confirming this. I have been saying, through my own experiments, that my X26 Pro when connected to the U18 via I2S uses the U18's clock. If the U18 has an external clock connected, it uses that.

 

[ray12345]

Thank you for confirming this. I have been saying, through my own experiments, that my X26 Pro when connected to the U18 via I2S uses the U18's clock. If the U18 has an external clock connected, it uses that.

It sure does. However, for X26 Pro at least, if external clock is connected to X26 Pro as well as to U18, the sound is still different, so X26 Pro does use the external clock when it is told to do so in settings, despite the fact that there is clock from I2S signal already.

 

[Highfive99]

It sure does. However, for X26 Pro at least, if external clock is connected to X26 Pro as well as to U18, the sound is still different, so X26 Pro does use the external clock when it is told to do so in settings, despite the fact that there is clock from I2S signal already.

My best SQ with U18 and X26P is with ext OCXO connected to both devices. It sounds amazingly good to my ears.

 

[JaMo]

My best SQ with U18 and X26P is with ext OCXO connected to both devices. It sounds amazingly good to my ears.

I agree on that. Same here.
/J

 

[DecentLevi]

I've been on the hunt for a quality BNC Cable to run with my LHY-OCK2 into the Gustard R26 feeding the Ferrum OOR / Hypsos & Susvaras. Up until today I've be using the Huber+Suhner enviroflex 400 cable silver coated stranded BNC Cable. The sonic presentation has good instrument texture, great attack on stringed instruments with plenty of detail / micro-detail but overall thin sound signature. Bass has amazing definition but no body, that is until today.

Build quality is outstanding. This thing is built like a tank with high quality parts. it's diameter dwarfs my previous cable. At a 12 inch length I did have to shape the cable a bit but there's plenty of flex to do so easily

Straight out of the box with no burn-in, sonic magic.

Pasternak BNC Male to BNC Male Low Loss Cable 12 Inch Length Using LMR-400 Coax With Times Microwave Parts SKU: PE3C6725-12

Find Here: shorturl.at/azBW2
$85.58 w/tax + shipping

I haven't added something to my chain with this degree of perceivable sonic improvement in a long time. I hate to overuse hifi terms but the sonic presentation now has body, weight, warmth, syrupy sound which the Susvaras aren't typically known for. Background blackness has increased as well.

Your link isn't working. Is this BNC cable any different than the LMR-400, or possibly better? I got one already, from AliExpress

 

[Flyblues]

It depends. Inter-chip connection do not require reclocking as traces are uniform/very short and a PCB wide ground plane creates an uniform voltage reference. These conditions are not met where we have two different devices, power supplies, lenght of the cable exceeds interchip values. It is why in general reclocking is recommended.

In this situation reclocking can be avoided only if both devices are synchronised to the same frequency. It is why we have 10MHz external clock input. If Gustard does otherwise (do not do reclocking or do not synchronise to the external clock when enabled), they are wrong.

Manufacturers who do this are following a design specification, that are there for reason, of a technical architecture. What is wrong with this?

Note: It does not mean that there are no alternative ways to implement the technical architecture. All alternatives may have their pro's con' and challenges, but that does not invalidate alternatives from the one selected one, or mean any of the alternatives is wrong.

 

[sajunky]

Manufacturers who do this are following a design specification, that are there for reason, of a technical architecture. What is wrong with this?

Note: It does not mean that there are no alternative ways to implement the technical architecture. All alternatives may have their pro's con' and challenges, but that does not invalidate alternatives from the one selected one, or mean any of the alternatives is wrong.

You are right that in many cases there are design alternatives, but a common case is just a simplification. In a case where you want to add galvanic isolation on the interface (as it is done in high-end Audio GD R-8/R-7 DAC), reclocking is absolutely necessary. As mentioned before, only the external sync solution like 10MHz clock eliminate a requirement for reclocking.

On a direct I2S connection (without galvanic isolator), direct clocking is acceptable, but it increase requirements for the cable quality, limiting lenght before degradation of sound is noticeable. Simplified/cheaper design, with no user benefits. So, you are right, there are options these are...

I don't know what specification you refer. There is no design specification for inter-device I2S. No one has drafted such technical architecture. In fact, the original Philips I2S specification make a provision for a feed-back clock. If implemented, it would eliminate reclocking, but no-one came with such idea. Briliant idea - wasted!

There were early attempts to deploy Ethernet signalling levels and RJ-45 connector without a major success. Then someone had an idea to use LVDS connection and standard HDMI cable, now everyone follow it.

 

[Psilonaught]

Hey fellas!
So a lot of you have heard both the OCK-1 and 2; anyone here who liked the 1 over the 2? If yes, what was your setup configuration like?
I'm looking to add a clock to my setup and have auditioned a few. The best yet was a Cybershaft but that was wayy over my budget.
I also auditioned both OCK1 and 2. While the 2 was defintely more "clear" and "detailed", it somehow felt a bit "sharp" and "bright" while the 1 was relatively "smoother" and "quite well rounded". Both were connected to a Singxer SU2 KTE with the Gustard Cable feeding a Holo Spring KTE.

Also there isn't much talk of the Gustard C18/C16, Aune S1c (or SC1) vs the LHY clocks; has anybody had a chance to compare them?

I've been reading this thread with interest since I recently bought an Audio GD R7HE which is easily the best dac I have owned. I now want a good quality clock.

There are specs available for the Aune S1C here https://device.report/manual/5599395

Phase Noise (10MHz)

1. <-100dBc @ 1Hz Offset

Therefore a) Aune report honest data and b) the performance is pretty average for the price.

Personally I am not at all surprised that the LHY units don't perform well, they are dirt cheap what do folks expect?!

The Gustard C18 as -110dDc which looks better assuming that is a genuine measurement.

 

[Igor375375]

Personally I am not at all surprised that the LHY units don't perform well, they are dirt cheap what do folks expect?!

That's not true. I have the LHY OCK-1, no complaints about sound quality.