今年還有雙11減價嗎？

有啲分別

用左效果明顯？

優惠碼: 11.11

要怎樣才享有9折？

要code嗎？

11:11 Cybershaft 所有型號 9折

https://www.adark.co/collections/cybershaft

得嗰十幾廿MHz 條線又唔係特別長，我試過喱種 75/50 插頭之間 terminal reflection 嘅分別對 signal integrity 嘅影響可以話係無。

Not sure why the Cybershaft's BNC output connector can be used for both 50/75 ohm. In normal practice, the 50/75 ohm bnc is certainly not the same type. Termination reflection echos may be a problem.

I saw this comparison table in a overseas forum, and I read the entire thread there as well.

Phase Noise Comparison from high hand.



最後修改時間: 2020-11-07 10:53:40

Thanks for your comprehensive information. No matter it is a commercial, industrial or mil products, some international standard has to be followed especially for the advanced digital application. Now, most of the products follow IEEE standard, such as the "Standard for Terminology and Test Methods for Digital-to-Analog Converters;” (IEEE Std 1696-2013) ", a new requirement (TC-10) is now proposed to address the issues of AM-PM noise as shown below. Nowadays, AM noise is observed also important to the digital signal jittering.

通常，商業級產品不會以1Hz偏移發布性能報告，這是大多數製造商都無法達到的敏感值，大多數產品僅以10Hz偏移測量其相位噪聲。Cybershaft is using 1Hz offset to measure their phase noise, which is critical to audio. All Cybershaft will have the graph showing the phase noise characteristics and the short-term stability (Alan variance) and choose carefully to distinguish their OP level for customer to choose with respect to quality level for audio.

The OCXO installed in this product uses a stable individual after several months of calibration of a new OCXO unit. In order to perform the optimum selection as a clock for audio, we perform a comprehensive evaluation of the phase noise characteristics and the short-term stability (Alan variance) that can be scrutinized more closely.

The product cannot be evaluated by measuring only the output characteristics of the built-in OCXO unit. Our calibration measurement is not directly on the output of the OCXO unit, but is measured from the output terminal of this product in order to evaluate all the performance including the buffer circuit.
And selection reference value

phase noise: OP20A-1 offset 1Hz at -120 dBc / Hz or less offset 10Hz at -140 dBc / Hz or less
　　　　　 OP21A-1 -140dBc / Hz or less offset 1Hz at -121dBc / Hz or less offset 10Hz
Allan variance short stability (Reference value)

OP20A-1 TAU = 1sec 2.5E-13 or less (0.00025ppb / s)
OP21A-1 TAU = 1sec 2.0E-13 or less (0.00020ppb / s)

The main criterion for grade selection at our company is the short-term stability value of Alan variance. For example, even if the phase noise value is -121 dBc / Hz or less at an offset of 1 Hz, OP21 will not be obtained if the short-term stability Tau = 1 sec value does not meet the standard. This is similar to the traditional OP grade selection method.

The above values ​​are not the general catalog values ​​(Typical) but the guaranteed values ​​measured individually, so the quality of the product is constant. There is no so-called "off".
* For the phase noise offset of 1Hz, an appropriate value with an offset of 1.000Hz to 1.099Hz is used to avoid averaging error. Phase noise measurements are very sensitive and have instrumental and measurement errors. The indicated phase noise values ​​include measurement errors rather than absolute values. The indicated phase noise value is a value measured under the same conditions of our company and is an index of product grading.

The short-term stability value of Alan variance is not clearly defined by international standards, so there may be a large error between calibration laboratories. The above selection values ​​will be the values ​​of our calibration equipment.

原子鐘個short term PN 不一定差過 ocxo。反之亦然。
乜牌子，乜原子鐘/乜ocxo, 重要的係入面個"鐘"。(當然，個鐘機的其他配套也重要。)

要將兩部鐘機比較，要比較short term PN.
If other things are equal, 相差2dBc，已唔同。

上網睇到,有冇師兄用過?
https://www.thinksrs.com/products/perf10.html

另外,請問cybershaft張証,係唔係廠試過咁意思?

atomic clock 比 ocxo 10m

我也都是實試....一班人都有相同感覺....

Cybershaft ocxo 10m 是 clock 應該有的整齊清晰, 但ocxo好難密度上有改善....我是代理引入香港前, 已做此測試, 早過好多香港用家認識

跟手再換回atomic clock 除左保持整齊清晰外, 仲有密度外, 音場深和闊好多, 樂器像真度亦改善不少, 似真樂器

至於看phase noise圖外, .......我想音樂也需用聽感吧...小弟玩鐘已十多年, 有玩樂器, 年年聽30場以上 classical 音樂會....聽慣的人自會分辨倒樂器像真度的分別....我也明分辨音樂本身其實也有一定的標準, 不是自己 happy 就得....但分辨倒樂器像真度聽慣就會明

atomic clock 比 ocxo clock 對 jitter 敏感度高好多(易濛過), 用錯線材容易衰聲過ocxo clock 好多....總之atomic clock用乜附件都要清晰, 愈清愈好, 否則效果易衰聲過ocxo clock

建議多聽多實試, 再去決定

我祗講如果有 $5皮...可以揀原子鐘而矣
可能我在此多言了.......不再回應....sorry

最後修改時間: 2020-10-24 23:05:32

我搵吓個phase noise圖，atomic clock比ocxo，揾到post上來

7哥，咁又係喎，以前我都以為原子鐘正，但我有機會俾人度吓個phase noise，原來差都無輪

玩audio, short-term PN 比較重要。
我很久用開Esoteric G-0Rb。近期加 OCXO input to G-0Rb, 個系統聲靚好多。

最後修改時間: 2020-10-24 12:46:03

原子鐘個short term phase noise (PN)會差過 ocxo, 但 long term holdover又會好得多，也許音响糸統是可以短暫trade off.

新款 Platinum UPOCXO-PL-01 有 op09 水平