Master Clock Talk

[Jake2]

From what I read here, the connectors don't get changed. If you order with a mix of outputs, the circuit impedance should be set to what you ordered. But you can't tell by looking from the outside. Maybe open the box and check if the DIP switches are set (not sure, but since it's user-configurable I guess there are DIP switches)

Exactly this. From recollection per a post in another thread LHY introduced the OCK-2 with its DIP switches for 50/75 ohm characteristic impedance, along with double the number of outputs (3 sine, 3 square) in response in part to multiple requests for variations to the OCK-1. Having a single model design with modifications limited to setting dip-switches and voltage as per customer request is far more efficient from a manufacturing and/or order fulfilment perspective than having to manage potentially multiple hardware modifications at an individual unit level.

I would like to think that LHY has accounted for the impedance of ‘50 ohm style’ BNC sockets (i.e. with dielectric material) in its design of its upstream impedance switching circuitry so as to deliver as close as possible to the desired/selected output/characteristic impedance - whether 50 or 75 ohms - from oscillator through to and including the BNC socket.

I mean if that approach (50 ohm style BNC socket with switchable 50/75ohm impedance) is good enough for Cybershaft’s USD10k OP21A-D Ultra Precision Master clock…

 

[rsbrsvp]

Exactly this. From recollection per a post in another thread LHY introduced the OCK-2 with its DIP switches for 50/75 ohm characteristic impedance, along with double the number of outputs (3 sine, 3 square) in response in part to multiple requests for variations to the OCK-1. Having a single model design with modifications limited to setting dip-switches and voltage as per customer request is far more efficient from a manufacturing and/or order fulfilment perspective than having to manage potentially multiple hardware modifications at an individual unit level.

I would like to think that LHY has accounted for the impedance of ‘50 ohm style’ BNC sockets (i.e. with dielectric material) in its design of its upstream impedance switching circuitry so as to deliver as close as possible to the desired/selected output/characteristic impedance - whether 50 or 75 ohms - from oscillator through to and including the BNC socket.

I mean if that approach (50 ohm style BNC socket with switchable 50/75ohm impedance) is good enough for Cybershaft’s USD10k OP21A-D Ultra Precision Master clock…

Fred A- who has a After Dark clock told me:

"Yes, indeed, i have two actual 50-ohm and one 75-ohm bnc connectors on my afterdark clock. I do not think using 50-ohm on a configurable clock like the Cybershaft makes such a difference."

 

[bludlivijkot]

Do you mind sharing which Ampenol plugs you got? Found 4 different options for 50ohm with the berillium copper. I suppose the 'extreme exposure' versions aren't needed, so then it's an RG-58 and an RG-174 version left (I'm completely clueless what is behind these numbers).

Please check which of these has larger tip for the cable, i've ordered with 1.3mm, but anyway, had to strip the cable a bit to pull it in. As the cable was 1.4mm

 

[bludlivijkot]

Do you mind sharing which Ampenol plugs you got? Found 4 different options for 50ohm with the berillium copper. I suppose the 'extreme exposure' versions aren't needed, so then it's an RG-58 and an RG-174 version left (I'm completely clueless what is behind these numbers).

I bought rg-58, but as i said, is center tip is 1.3mm so if you'll use that eacon 4c, a bit os stripping will be needed. Not perfect solution

 

[kvad]

I bought rg-58, but as i said, is center tip is 1.3mm so if you'll use that eacon 4c, a bit os stripping will be needed. Not perfect solution

Thank you! I see Huber+Suhner has a recommended plug as well. Perhaps that might be worth a shot? Or is Amphenol considered the better plug?

 

[bludlivijkot]

Thank you! I see Huber+Suhner has a recommended plug as well. Perhaps that might be worth a shot? Or is Amphenol considered the better plug?

Take then recommended plug. Will be easier to fit

 

[rsbrsvp]

I just received my "After Dark" clock. It was supposed to have some outputs at 50ohm and some at 75ohm. But all the BNC outputs look the same.

I thought the 50 ohm outputs have thicker plastic around the pin to differentiate it.....

Could someone please advise me if this is correct....

O.K. I contacted "After Dark" and they told me that all my outputs are "self adjusting" meaning they know when a 50ohm or 75ohm component is attached to it and automatically adjust. This is very hard to believe. I know cybershaft has a a switch- but "self adjusting" is something I never heard of.

How do I confirm of this is true.

 

[sajunky]

O.K. I contacted "After Dark" and they told me that all my outputs are "self adjusting" meaning they know when a 50ohm or 75ohm component is attached to it and automatically adjust. This is very hard to believe.

Yes, while possible. It would need some discrete implementation, as I never heard of interface chip with such feature.

The next question is when such autosensing is done: once off during power on sequence, or continuously? If the later, then it would trigger my highest allert.

Then is a rethoric question on a practical purpose. Would their autosense circuit detect wrong impedance of a cable? I am quite convinced that half-solutions for fixing user stupidity are the most stupid in the universe.

 

[rsbrsvp]

My next question is how much does burn in make a difference with these clocks?

My Hibiki clock at -113 sounds equally good to my ears as my new After Dark at -121. The After Dark only has two days burn-in; but as things stand- it is about a tie.

What can I expect?

 

[rsbrsvp]

Another question.

How important is the PS on a clock. Would a clock rated -121 with a good PS sound better than a clock rated at -115 with a much lower noise PS, or the opposite?

 

[ChJL]

Concerning the OCK-2, when to choose 50 or 75 Ohm setting?
Is the deciding factor the device I intend to connect it to? The connectors of that devices respectively?
And after that one gets the right cable?

Why choose sine over square wave? Or vice versa?
Thanks!

 

[gimmeheadroom]

Concerning the OCK-2, when to choose 50 or 75 Ohm setting?
Is the deciding factor the device I intend to connect it to? The connectors of that devices respectively?

Yes, devices are expected to have the right connector (sadly they often don't) to match the impedance of the clock setup.

Most hifi gear that uses 10 MHz clocks uses 50 ohm setups.

All pro gear uses 75 ohm WCLK or DSD clock.

And after that one gets the right cable?

Yes.

Why choose sine over square wave? Or vice versa?

Square waves have a nice sharp edge to trigger on. Audio-gd recommends square wave clocks and Mutec's clocks are all square wave. Look at the REF10 pages, there's a lot of interesting info and commentary there.

I think sinewave clocks are also a new hifi thing / bad idea

 

[PeterCraig]

My next question is how much does burn in make a difference with these clocks?

My Hibiki clock at -113 sounds equally good to my ears as my new After Dark at -121. The After Dark only has two days burn-in; but as things stand- it is about a tie.

What can I expect?

I'm burning my new OCK-2 in for 4 weeks before I do any critical listening. And then another 4 weeks before I do any comparison to my old clock. Sounds pretty crummy right now after 3 or 4 days.

 

[Jake2]

Square waves have a nice sharp edge to trigger on. Audio-gd recommends square wave clocks. I think sinewave clocks are also a new hifi thing / bad idea

I respectfully disagree. Sine sounds much better than square with my OCK-1 and Gustard C2 cable. Square theoretically better in a perfect setup but sine theoretically more forgiving of internal reflections (from anywhere in the chain from OXCO inside the clock, within the cable, and from the cable/BNC plug junctions) than the nice sharp edge of square which is not so nice if it gets messed up.

I used square for a month assuming sine would be worse, then kicked myself when I tried sine. Haven’t looked back. YMMV with different DACs, DDCs, clocks, cables etc. Great to have the option.

@ChJL My advice try both and use whatever sounds better.

 

[ChJL]

@sajunky @JaMo @Jake2

Since I plan to bridge a ca. 15m distance between the routers potential new place and the switch/player I plan on using a fibre connection.

https://www.futureshop.co.uk/adot-mc-fibre-network-kit
(Adot=Melco)

Not a cheap solution (but vs 15m lan cable who knows) and I can't find anything about single or multimode...

What's your opinion on mentioned device?

LHY's SW-10 is supposed to be released in Q1/23 which could be used, to stay on topic here, with a masterclock.