这个钟是什么水平？有人了解么
本帖最后由 Astralark 于 2016-9-26 23:59 编辑http://www.cybershaft.jp/a-products/limited.html
Antelope 10M 的 LCR-900 就不提了
直接说 Esoteric G01 吧, SRSPRS-10，1hz 为 -102dBc/Hz , 10hz -130dBc/Hz , 100hz -140dBc/Hz, 计算下 RMS phase jitter 1-100hz = 136fs，价格2万3美金
我列这个牌子一千美金的普通型号，1hz 为 -110dBc/Hz , 10hz -130dBc/Hz , 100hz -140dBc/Hz, 计算下 RMS phase jitter 1-100hz = 75fs ／ 旗舰型号不到三千美金, 是限定版，款式分布有多复杂（Rakon HSO-14），1hz 为 -122dBc/Hz , 10hz -130dBc/Hz , 100hz -140dBc/Hz, 计算下 RMS phase jitter 1-100hz = 35fs
有没有大神了解这个牌子，这是吹牛逼，还是真牛逼？
thinksrs的10M很屌啊
二嫂的钟本来就是srs的oem内芯…… 恭喜啊，又发现新火星了
感觉没有楼主的光学望远镜牛逼 本帖最后由 Astralark 于 2016-9-27 00:15 编辑
虽然外接钟有问题，本来就是给 Pro Audio 远距离传输统一用的
Why external clocks are junk for home audio applications
Hi guys,
It's extremely annoying reading about these 10Mhz external clocks with extremely low phase noise specs. The phase noise of the OCXO's in these clocks are absolutely irrelevant when it comes to the jitter performance of what it's clocking. Since we want educated clients and forum members, here's why these external clocks are total junk when it comes to home audio applications, no matter how low the phase noise is on the internal clock:
1: Most are all based on a 10Mhz OCXO. It's not hard to get extremely low phase noise at 10Mhz. But 10Mhz is useless for audio. You need multiples of 22/24Mhz to be useful for audio. So they must use a PLL generator to generate these frequencies, using the 10Mhz clock as a reference. However the phase noise/jitter of the generated frequency is far higher than the reference clock. So the only figure that is relevant is the phase noise of the frequency generated taken from the external output. But nobody ever publishes that figure!!
2: Even if you still have decent phase noise performance from the PLL generated clock output, by th e time the clock goes through the 2 connections, cable, and all of the connections in the DAC, so much jitter is added, that locating a $20 Crystek an inch away from the DAC chip will result in far lower jitter/phase noise at the only place it actually matters. Even if you are using a $20000 external clock.
The reason these external clocks were made from the beginning was to clock multiple devices in a studio environment. It was the only way to sync up the clocks between all of the ADC's, DAC, mixing boards etc, in a studio before AES67 came along. So it was out of necessity, not for performance reasons.
So why are these clocks sold to the audiophile market? To suck your money out of your wallet that's why. If it sounds better to you, there's only 2 reasons why:
1: The clock it's replacing in your DAC is total junk, so using the external actually does make a difference for the better.
2: Expectation bias based on price and beliefs.
The only good solution is putting that ultra low jitter clock into the DAC very close to what it's clocking. And not a 10Mhz clock either, it must be a multiple of 22/24 Mhz if you don't want to use a jitter adding PLL generator. aligaduo 发表于 2016-9-27 00:06
恭喜啊，又发现新火星了
感觉没有楼主的光学望远镜牛逼
谢谢，我只是发出来逗一逗你们，外接钟用不到 amex 发表于 2016-9-27 00:04
thinksrs的10M很屌啊
二嫂的钟本来就是srs的oem内芯……
反正 LCR-900 是垃圾 amex 发表于 2016-9-27 00:04
thinksrs的10M很屌啊
二嫂的钟本来就是srs的oem内芯……
反正 LCR-900 是垃圾 RMS phase jitter 的频率范围最好算宽一点
譬如1-1Mhz
西格玛的DAC，对高频的抖动依然敏感哦。
要求高一点，就计算0.1Hz到10Mhz:lol lcr900是毛？ 不懂帮顶 羚羊10m的核心是standford research systems也就是srs的prs10。羚羊其实就是srs perfection 10的商业化产品。两个机器就是换了一个壳。 本帖最后由 amex 于 2017-5-30 00:20 编辑
reformatsky 发表于 2017-5-29 23:01
羚羊10m的核心是standford research systems也就是srs的prs10。羚羊其实就是srs perfection 10的商业化产品 ...
二嫂的才是
羚羊的一代10M应该不是srs的，参数都对不上
而且他新一代标出来的近端相噪也是垃圾水准，何况他老一代只敢标精度233
看了下他新官网，居然标了老10M的10hz offset参数，有140……
那他新款不是瞬间爆炸;P
可是还是和srs的参数对不上，140@10hz是好于srs的
amex 发表于 2017-5-30 00:17
二嫂的才是
羚羊的一代10M应该不是srs的，参数都对不上
而且他新一代标出来的近端相噪也是垃圾水准，何 ...
还有，比参数啥的没有太大意义，srs perfection 10声称用的自己prs10灯泡，但是你查一查perfection 10的参数居然和prs 10不一样。 reformatsky 发表于 2017-5-30 00:32
还有，比参数啥的没有太大意义，srs perfection 10声称用的自己prs10灯泡，但是你查一查perfection 10的 ...
猜猜我发现了什么？
提到prs10的地方如果是这个pdf的话，那这个意思可不是用了prs10，而是用了与prs10兼容且等效的FEI5660
https://repo.antelopeaudio.com/downloads/10m_atomic_clock/software/Isochrone_10M_Atomic_Clock_%20DataSheet.pdf
这是FEI5660的参数
http://freqelec.com/prod_pdf/fei-5650a_ds.pdf
10hz参数只有-100……
另外timenuts上有个讨论证实了这点
https://www.febo.com/pipermail/time-nuts/2014-March/083979.html
Some FE5660s, from Tait T801 UHF base station references, becameavailable
on the UK surplus market a few years ago andI've always considered them a
possible equivalent of the Efratom FRSseries, physically and electrically
quite similar, but have never consideredeither to be an equivalernt of
the PRS10.
羚羊果然一贯套路
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