Master Clock Talk

[yukio1965]

I bought direct from Taobao. If you can't go through Taobao direct, I guess something like this also works :

https://www.aliexpress.com/item/3256804751742784.html?spm=a2g0o.productlist.main.27.2f422cc0nB1Qsr&algo_pvid=cd6dec45-f957-4175-84e3-ef2e57fcb4c1&algo_exp_id=cd6dec45-f957-4175-84e3-ef2e57fcb4c1-13&pdp_ext_f={"order":"1","eval":"1"}&pdp_npi=4@dis!USD!19.89!19.89!!!19.89!19.89!@2101246417433994253887814e0aaa!12000031084572649!sea!US!0!ABX&curPageLogUid=RNNhhuG4UAnh&utparam-url=scene:search|query_from:

Could you post a picture of the converter?

 

[Jake2]

I am using a 75ohm Oyaide BNC cable on my 50Ohm Gustard X30 DAC. I have also previously used 50 ohm Harmonic Tech DC3. I would say the quality of the cable affects the sound more than whether it is 75 or 50 ohm.

Anyway, there are 75->50 ohm convertors, I used them now and it brings the vocals even more detailed now.

That’s interesting thanks Ray, what are the settings of your OCK-2S output feeding the X30?

I’m guessing it’s sine and still 50 ohms, if so your transmission line would be:
Clock output (50 Ω) > 75 Ω Oyaide cable > 75/50 Ω adaptor > X30 50 Ω input.

Which would be consistent with Cybershaft’s experience that a 75 Ω cable can work really well in an otherwise 50 ohm transmission line. Albeit you get a further improvement adding the adaptor.

 

[ray12345]

That’s interesting thanks Ray, what are the settings of your OCK-2S output feeding the X30?

I’m guessing it’s sine and still 50 ohms, if so your transmission line would be:
Clock output (50 Ω) > 75 Ω Oyaide cable > 75/50 Ω adaptor > X30 50 Ω input.

Which would be consistent with Cybershaft’s experience that a 75 Ω cable can work really well in an otherwise 50 ohm transmission line. Albeit you get a further improvement adding the adaptor.

No OCK-2S has 75ohm output on one of the BNC, I use square wave, as I find square wave provides more resolution, while sine wave produces a smoother sound.

I use the following connection :

75 ohm OCK-2S output -> 75 ohm Oyaide cable -> 75 to 50 ohm adaptor -> x30 50 ohm clock input

 

[yukio1965]

No OCK-2S has 75ohm output on one of the BNC, I use square wave, as I find square wave provides more resolution, while sine wave produces a smoother sound.

I use the following connection :

75 ohm OCK-2S output -> 75 ohm Oyaide cable -> 75 to 50 ohm adaptor -> x30 50 ohm clock input

Could you post a picture of the converter?

 

[ray12345]

Could you post a picture of the converter?

mine look like this

 

[sajunky]

mine look like this

It has probably resistor in series. In such case it could be used in both directions, but marking indicate that it should be rather used for plugging to the 50 Ohm clock output.

 

[cauwil]

I have the cybershaft one to be plugged on the clock input 50 ohms -> 75 ohms. It is only a 150 ohms resistor put in parallel...

 

[sajunky]

I have the cybershaft one to be plugged on the clock input 50 ohms -> 75 ohms. It is only a 150 ohms resistor put in parallel...

Resistor 150 Ohm in parallel to 75 Ohm terminator inside the socket gives total 50 Ohm.

1/75 + 1/150 = 1/R
result: R = 50

It is rather for connecting 50 Ohm cable to the 75 Ohm port. It could be either clock output or input, no matter. There is no voltage loss, like in the case of resistor in series, just a bigger load (current) for a driver.

This is what @ray12345 needs. As long as clock device is capable driving increased current (it needs to be verified with the vendor), it is a solution.

 

[demi88]

Resistor 150 Ohm in parallel to 75 Ohm terminator inside the socket gives total 50 Ohm.

1/75 + 1/150 = 1/R
result: R = 50

It is rather for connecting 50 Ohm cable to the 75 Ohm port. It could be either clock output or input, no matter. There is no voltage loss, like in the case of resistor in series, just a bigger load (current) for a driver.

Are you sure the math is applicable to “characteristic impedance”?

Afair it depends on the cable diameter, distance between cable and shielding etc

 

[sajunky]

Are you sure the math is applicable to “characteristic impedance”?

Afair it depends on the cable diameter, distance between cable and shielding etc

I am sure, it does not. Not sure how you figured it out. Resistor in the adaptor adjusts value of termination. It has nothing to do with the characteristic impedance of the cable.

 

[demi88]

I am sure, it does not. Not sure how you figured it out. Resistor in the adaptor adjusts value of termination. It has nothing to do with the characteristic impedance of the cable.

Right, ive lil bit messed up here

 

[MartinWT]

The reason why cable impedance doesn't matter for sinewaves compared with squarewaves is that the latter are made from an infinite series of odd harmonic sinewaves as shown in the diagram. Therefore, the cable needs to have a very high frequency response with no phase distortion in order to transmit the squarewave accurately, in other words correct characteristic impedance throughout.

A sinewave clock only requires the cable to transmit a 10MHz sinewave accurately and no other frequency. Characteristic impedance therefore doesn't matter (between 50 and 75 ohms).

 

[ray12345]

It has probably resistor in series. In such case it could be used in both directions, but marking indicate that it should be rather used for plugging to the 50 Ohm clock output.

I thought it is probably just resistor in series as well, I asked specifically the vendor the question why there is direction, the vendor just says that is how this thing works. You can specify the direction when you buy, so it can fit all purposes. Whether there are really hardware differences for different directions, or whether it is just a label so that they can sell more of these adapters, I really don't know .......

EDIT : I just did further testing, the adapter is affecting transparency and details, it is better not to use the adapter at all. Just plug the 75 ohm cable direct into the 50 ohm clock input, I use square wave, and it is still better to plug in direct.

 

[cauwil]

There is a new clock by LHY : the OCK-1S - not so expensive if it performs as the OCK-2S does...

 

[yukio1965]

I connected the Afterdark "Emperor Double Crown" clock to the AudioGd Di20 interface which is in turn connected to the AudioGd Master 7 dac via I2S.
It's crazy what the Emperor Double Crown does, crazy!!
An improvement that has revolutionized my stereo system!
Everything cleaner, more alive, more focused, everything more real!
I had tried a LHY OcK1 clock and I had noticed a slight improvement.
The improvement that the Afterdark Emperor Double Crown brings is incredible and makes you consider the LHY clock as garbage.
Now I have to choose a good BNC-BNC cable for the clock.
I am undecided between the Neotech NEVD 1001, the Oyaide BC-510 and the Furutech FX-Alpha digital AG.
Which one would you recommend among the three mentioned, and why?
As for the length of the BNC cables to be used with the clock, is it true that it must be at least 60 cm?