一次完美的“downgrade”- Linger Audio - Apodidae ocxo switch

tleonard

其實外置 10MHz 嘅 reference clock 的確係比較蝕底，就算鐘線同埋 reference clock 幾貴都最多係同內置 OCXO 打成平手：

https://www.head-fi.org/threads/review-comparison-of-5-high-end-digital-music-servers-aurender-n10-cad-cat-server-totaldac-d1-server-auralic-aries-audiophile-vortex-box.787020/page-79#post-14120317

As you've pointed out, the parts used for this upgrade could be better which is why I was a bit surprised by how much it improved. As always, it's how these parts are implemented that can make a bigger difference and combined with very short signal paths (i.e. no convoluted signal paths or long clock cables were necessary), the quality of the clock signal actually seen by the system board is possibly higher than the quality of the clock signal seen by components such as a tX-USBultra or sMS-200ultra even though they use superior clocks.

One of the things I learned about the REF10 is that Mutec's published phase noise measurements were taken from the BNC output and not from the clock itself and so comparing the phase noise plots of REF10 to another external master clock may not be a true apples to apples comparison and this highlights my point. I predict that by the time the clock signal goes through whatever length clock cable you use to connect the REF10 to something like the sCLK-EX board in my tX-USBultra and by the time that clock signal reaches the USB hub in my tX-USBultra, that signal may have become significantly degraded and so this is the potential benefit of physically placing a good clock in the same location as the old clock.

計一計條數，隻 D-Link switch 本身唔值錢，SOtM sCLK-EX 就起碼 700 美金，半米 Habst 鐘線要 700 歐羅，Mutec REF 10 就足足 3595 美金，夾夾埋埋就港紙幾萬銀。

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點知一件 589 美金（加埋運費就港紙五千有找）嘅內置 OCXO switch 居然未煲好嘅時候已經同幾萬銀嘅組合有得揮：

http://thelinearsolution.com/ocxo_switch.html
http://thelinearsolution.com/assets/files/TLS-2018%20PRICE%20LIST.pdf
https://www.head-fi.org/threads/review-comparison-of-5-high-end-digital-music-servers-aurender-n10-cad-cat-server-totaldac-d1-server-auralic-aries-audiophile-vortex-box.787020/page-78#post-14117902

This OCXO switch from The Linear Solution is at least as good as my DLink switch and with further burn-in, it may turn out to be convincingly better. At the present time, my DLink switch has a touch more smoothness and a touch less glare but music streamed through the OCXO switch definitely has more of a "you are there" presence and this switch seems to still be improving. If I can get this slight harshness to go away, my preference is definitely for The Linear Solution OCXO switch. Compared to "no switch," the Netgear GS108, or the Paul Pang TCXO, I would definitely go with The Linear Solution switch. When you factor in the cost of a REF10 and sCLK-EX board, my SOtM-modified DLink switch can only be considered a good value when these items are also used for other components such as a tX-USBultra or sMS-200ultra. While the Aqvox SE switch appears to be a better standalone value at 798 Euros (or nearly $1k USD), I have not yet heard this switch and so I can't really render an opinion but at only $659 for The Linear Solution switch, this switch will be tough to beat.

最抵死嘅就係粒 25MHz 嘅 OCXO 只需要 55 美金：

https://www.digikey.com/product-detail/en/connor-winfield/OH4610LF-025.0M/CW899-ND/5641634

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所以最大件夾抵食嘅就係上 Amazon 或者淘寶搵隻 Netgear GS305：

https://item.taobao.com/item.htm?id=569137782194
https://www.amazon.com/NETGEAR-Ethernet-Unmanaged-Internet-Splitter/dp/B00QR6XFHQ

跟住將圖中 Y1 嘅 25MHz 時鐘換咗做 55 美金嘅 OCXO：

https://imgur.com/a/L4fME7W


供電就當然係用史上最低 noise 嘅 LT3045，隻 GS305 同埋粒 OCXO 要分開 5V 供電：

http://www.ldovr.com/product-p/lt3045-a.htm
https://www.ebay.com/itm/LT3045-A-Ultralow-noise-0-8-Vrms-LDO-linear-regulator-0V-15V-1A-Fixed-out/253378132579

Torres

tleonard 發表於 2018-6-27 14:34
其實外置 10MHz 嘅 reference clock 的確係比較蝕底，就算鐘線同埋 reference clock 幾貴都最多係同內置 OC ...

外接10M 鐘，靚鐘連靚線三幾萬真係是很平常，但都只係同內置OCXO差不多，咁講如果外置OCXO咪會更無優勢?

blau.vol

Torres 發表於 2018-6-28 03:32
外接10M 鐘，靚鐘連靚線三幾萬真係是很平常，但都只係同內置OCXO差不多，咁講如果外置OCXO咪會更無優勢? ...

Hi Tores ,

其實大部份 external 10Mhz clock ,  like Mutec one is using third party europe made OCXO module but really really good one.   

For 10Mhz clock frequency ,  got many different way for the  implementation  , like  TCXO, TCVCXO, OCXO and VCOCXO or Rh.   we should consider about the accuracy and phase noise of each implementation (assume they release the related data or diagram)  

a good accuracy OCXO or Rh clock(like 3ppb) may have very high phase noise,  like 1Hz ,  -70dB and the lowest still -150dB .  

For the best 10MHz Master clock ,  we can found in the high end audio market , is 1ppb with   -121dB for 1Hz (+-)  and -172dB for 100KHz(+-) .

For 10Mhz clock to work with 25MHz SoC IC device ,  we need to implement additional PLL circuit ... ,  那可以有好多變數同可能有更多的jitter ( 要好睇線路)   好多時,  有時不implementation this PLL multiplier and use clock module freq directly is the best way.  

而另一方面 , 好的TCVCXO 的 Phase noise,  and lowest noise floor 都比同價的 OCXO  phase noise 好.  我想好多時, 我地好希望一個 25MHz 的SoC IC 去由一個10Mhz  take reference,  我地首先要知道個 10MHz  如何被使用. 以及有關的使用線路.  

但無論是 OCXO,  TCVCXO or OCVCXO,  最後都係要睇兩邊的數字.  Phase noise table and accuracy ( if they published ) .   
Best,
blau

clplarry

blau.vol 發表於 2018-6-28 09:10
Hi Tores ,

其實大部份 external 10Mhz clock ,  like Mutec one is using third party europe made OC ...

Your statement is too technical to be understood. Nervertheless, the best way is to beleive our ears to decide which one sounds best no matter the price of the devices. Of course, the price difference may sometimes reveal the sonic quality of the devices. And, for example, if a device costing 1/10 to 1/2 of the price of another high priced device but obtains 80-90% sonic performance of that high priced one, I will assume the low priced one is the best value one though it was beaten by the very high priced device in a little margin.     

diamondblack

clplarry 發表於 2018-6-28 11:02
Your statement is too technical to be understood. Nervertheless, the best way is to beleive our ea ...

There's nothing really technical at all in blau's response to be honest. Just a few metrics and names one should look for and a "kind reminder" that design and implementation have quite some influenence.

By the way, human's hearing can be highly manuipulative.

tleonard

Torres 發表於 2018-6-28 03:32
外接10M 鐘，靚鐘連靚線三幾萬真係是很平常，但都只係同內置OCXO差不多，咁講如果外置OCXO咪會更無優勢? ...

首先要分清楚外置 10MHz 嘅 OCXO 係叫做 reference clock，而內置 25MHz 嘅 OCXO 就係 system clock。CAS 嘅其他部份都需要佢哋自己嘅 system clock，例如一般嘅 x86 底板用 14.318MHz，USB 2.0 用 12MHz 或者 24MHz，LAN 同埋 USB 3.0 就一樣係 25MHz，而 Raspberry Pi 就用 19.2MHz。

仲有 44.1kHz 系列同埋 48kHz 系列用嘅 word clock，基本上係用 22.5792MHz 同埋 24.576MHz 倍數嘅鐘，例如史上最強（其實 MSB 嘅 Femto 33 仲勁，不過要 19,900 美金）嘅 NDK DuCULoN 就有 45.1584MHz 同埋 49.152MHz 兩款。ESS SABRE DACs 就比較特別，通常係用一粒 100MHz 就搞掂。

問題係 reference clock 同埋 word clock 用嘅 frequencies 係千篇一律，所以選擇比較多，但係 system clock 相對嚟講就比較棘手，例如要搵一粒 Raspberry Pi 用嘅 OCXO 都幾難，基本上就只係得 Neutron Star 2 同埋 Neutrino 2 可以揀，咁 x86 底板又點算呢？

於是泡菜佬 SOtM 就整咗件 sCLK-EX，一塊板有四個輸出，而每一個輸出都可以任你決定 system clock 嘅 frequency，所以 14.318MHz 都一樣做得到，後期仲可以加錢整多件 50Ω 或者 75Ω 嘅 reference clock input，咁就有得駁外置 reference clock。

簡單講句通常 reference clock 係用粒外置嘅 10MHz OCXO 去『調教』（英文係 discipline）其他無咁勁嘅 system clock(s)，理論上係會如虎添翼，不過關鍵係 reference clock 一定要俾隻靚牛佢用，而且條鐘線嘅長度同埋質素都非常敏感，最後就係鐘線嘅線身／鐘線嘅 BNC 頭／BNC input／BNC output 全部都需要統一 50Ω 或者 75Ω。

搞咗一大餐之後又會唔會得到法國大餐呢？問題嘅癥結係 SOtM sCLK-EX 塊板本身係有四條 cheap 到嘔嘅 50Ω 線，每一條線都係用細細粒容易食嘅 Hirose U.FL 頭，基本上咁鬼幼嘅 50Ω 線係唔會有好嘢，某程度上嚟講係俾呢一個樽頸位累死，結果係俾 degradation 搞串個 party。

就算 Mutec REF 10 識飛都好，再加埋一條地線分離嘅 Habst 鐘線（最短都要半米，再短嘅話就好難就到位駁線）都未必能夠力挽狂瀾，最後都係同內置嘅 55 美金 OCXO 打成平手。情況就類似俾好多錢買隻好正嘅 LPS 加埋勁靚嘅 DC 線，首先 5.5mm 嘅 DC 插座本身嘅 impedance 好高，效果點都無 XLR 插座咁好，再加上 DC 插座同埋插頭本身唔可以太軟，所以兩者用嘅金屬唔可以用純銀或者純銅，於是電導率就會大打折扣。俾你解決咗 DC 插座／插頭嘅問題又點呢？一部 CAS 或者一隻 NAS 入面仲有其他 voltage regulators，例如 SSD 係用 5V，所以就咁用 12V 嘅靚靚 LPS 餵佢嘅時候就無論如何都要將佢降低到 5V 先得，於是乎最乞人憎嘅樽頸位又蒲頭喇，因為例牌係俾一件 switching regulator 佢用，卒之最後嘅結果就會變咗『到喉唔到肺』咁解。

（查實 SSD 都可以分開供電俾佢，擺脫 switching regulators 嘅枷鎖，效果亦都相當顯著，不過假如係 RAM 之類嘅話就要 mod 咗塊底板之後先至有得另外餵 1.3V 俾佢。）

呢個故事教訓我哋，係呀，就算你落足本用正嘢餵佢都好，基本上嚟講可以話係隔山買牛又得，隔山打牛亦得，法國大餐都得。

racewong

tleonard 發表於 2018-6-28 14:48
首先要分清楚外置 10MHz 嘅 OCXO 係叫做 reference clock，而內置 25MHz 嘅 OCXO 就係 system clock。CAS ...

學左好多野， 多謝分享。

tleonard

racewong 發表於 2018-6-28 15:23
學左好多野， 多謝分享。

唔敢當，其實好多嘢都係睇完幾百頁嘅 posts 之後先至明，基本上差唔多每一日都好似煲劇咁煲：

https://www.computeraudiophile.com/forums/topic/30376-a-novel-way-to-massively-improve-the-sq-of-computer-audio-streaming/

個別嘅公司都好有可能係爬完文之後就開始炮製各式各樣嘅 OCXO 產品，不過幫 system clocks 改 TCXO 鐘嘅始祖應該係 Paul Pang 同埋 Ben Sir。

暫時嚟講比較勁嘅 system clock 應該係 Neutron Star 2，不過就要三千幾港紙先至有交易，供電方面就最好係 15V，所以 LT3045 就啱啱好：

http://www.newclassd.com/index.php?euip=1&page=200&hv=1

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唔知道 UpTone Audio 佢哋嘅進度如何，不過照計就今年之內佢哋會推出一隻獨家設計嘅 switch，由頭到尾嘅所有部分都係 John Swenson 親自操刀：

https://www.computeraudiophile.com/forums/topic/38968-etherregen-early-general-details-please-dont-ask-too-many-questions-yet/

PhantomGTR

tleonard 發表於 2018-6-28 14:48
首先要分清楚外置 10MHz 嘅 OCXO 係叫做 reference clock，而內置 25MHz 嘅 OCXO 就係 system clock。CAS ...

多謝師兄分享！

diamondblack

tleonard 發表於 2018-6-28 14:48
首先要分清楚外置 10MHz 嘅 OCXO 係叫做 reference clock，而內置 25MHz 嘅 OCXO 就係 system clock。CAS ...

DC直feed，知易行難。

Torres

diamondblack 發表於 2018-6-28 17:31
DC直feed，知易行難。

其實HIFI 野的技術相信都唔係咩新技術高科技，但真係知易行難。

好多時數據好好。理論上理想，但就係唔能夠取悅耳仔。所以到最後都係耳仔收貨好了。

clplarry

tleonard 發表於 2018-6-28 14:48
首先要分清楚外置 10MHz 嘅 OCXO 係叫做 reference clock，而內置 25MHz 嘅 OCXO 就係 system clock。CAS ...

You are really very keen and knowledgeable in the digital cyber field.

diamondblack

Torres 發表於 2018-6-28 17:59
其實HIFI 野的技術相信都唔係咩新技術高科技，但真係知易行難。

好多時數據好好。理論上理想，但就係唔 ...

要諗清楚「數據好好」係乜嘢意思。俾你睇到好好睇嘅數據，唔一定同你想知想量度嘅嘢有關係。

racewong

diamondblack 發表於 2018-6-28 18:20
要諗清楚「數據好好」係乜嘢意思。俾你睇到好好睇嘅數據，唔一定同你想知想量度嘅嘢有關係。 ...

所以HIFI先咁好玩...

你話好聲, 我話唔好聲.

睇數據又唔代理D咩...haha..

攪到我都好迷網呀...

diamondblack

racewong 發表於 2018-6-28 22:17
所以HIFI先咁好玩...

你話好聲, 我話唔好聲.

版主，你曲解咗我嘅意思。

AmbagoAudio

借位作出定價調整通知

Linger Audio 及小店十分感恩師兄們對Apodidae 的認同及支持，Apodidae 的反應比預期踴躍 ，現一直處於Backorder 的狀態。

小店昨晚收到Linger Audio 的正式通知，由於其OCXO存備被Apodidae 使用的速度比預期快，現存的數量也開始緊張，當需要重新定製時，成本將有一定程度的提幅。所以Apodidae也將會隨著成本提高而調整售價，冀各師兄見諒 。

由7月21日起Apodidae 將更新定價為$3480，由現在至7月21日前訂購Apodidae 的師兄，價錢將維持不變 。
升級選配Keces P3 +$2180(送鍍金FUSE，價值$80)。

歡迎師兄們WHATSAPP 或致電6889 3332查詢。或者師兄可按以下網址，直接WHATSAPP 聯絡：
https://api.whatsapp.com/send?phone=85268893332

小店亦能以順丰郵寄方式，把貨品寄往客戶指定的順丰站或智能櫃，方法為先轉款後兩天內寄出，請WHATSAPP 查詢。

師兄們是可瀏覽小店的facebook 網頁，www.facebook.com/ambagoaudio，按讚及追蹤並收看小店最新的資訊，謝謝。

hksarac

玩/聽音響，玩完電繼續又玩switch

CKL

With RPi 3B+, I switch to WiFi avoiding EMI from Ethernet.

clplarry

CKL 發表於 2018-7-3 13:36
With RPi 3B+, I switch to WiFi avoiding EMI from Ethernet.

Did you order the Raspberry Pi 3B+ from RS of Hong Kong? What's its difference from the old Pi 3B?

CKL

clplarry 發表於 2018-7-3 18:16
Did you order the Raspberry Pi 3B+ from RS of Hong Kong? What's its difference from the old Pi 3B? ...

Yes, ordered from RS HK. Faster CPU, with WiFi and Bluetooth. If you use WiFi to avoid Ethernet, the USB has become usable.