錄音技術是不斷進步，60年代已經可以錄下當時比較前衛作品，當時製作人應該都需要考慮錄音技術與重播技術平衡下去創作，不過一般人嘅重播系統都未必達標去欣賞。

Lalalam master

thxthx thx
我是不怕醜講出自己的想法，錯也不會覺得面懵的

哈哈，就係咁樣就有一些唔介意教別人的，會用心說明一點點，那就學多一點點

哦你說的東西我大概明白，記得我舊時團隊負責兩個賣得幾好嘅2.4 ditigal 遙控器系統，工程團隊都同我講過一啲back to back timing 出現問題，同你講嗰啲差唔多,玩平價遙控玩意的人都應該用過我處理的兩個品牌 haha

以往久唔久就要去粉嶺sgs睇下點樣出貓 pass emc，多年前的事情了 haha

你說的就代表了，我現在用一條active usb線notebook to DAC, 嚴格要求來說是不好的




最後修改時間: 2025-09-12 19:56:47

Haha兄......first come to mind 優化嘅buffer咪得囉....

其實唔得，so far民用音響用的protocol是屬於比較低層次, audio data block 是一個跟一個，本身並沒有time stamp, 而因民用網絡的network latency是頗高的, 於是audio data block就會像下圖的VP般産生不對齊現像，而紅短線代表的buffer clock 卻以固定速度送出audio data, therefore in this way audio jitter will happen and cause distortion. 所以專業音響就會用一種叫AES67 的 protocol 就以半 deterministic networking 的形式去降低latency, 而再更高層次就會用所謂time stamp protocol, 多數用來做process control去控制電力或者快速飛行物體，而呢種網絡就叫full deterministic network。

我都有部樹莓倉存了!

亦有唔少人玩Raspberry pi。

我用Mac Mini M4 + Audirvana 播local files减少煩惱，而且用電量非常少又唔熱又冇風扇聲!

最後修改時間: 2025-09-12 12:33:38

PC行Linux已經好多年，不過要set得好都係要軟硬件配合，其實Windows都可以專門優化，不過技術唔會比Linux低，基本音樂檔案在進入DAC前都係電腦技術，視乎需要及能力去選擇方案。

Router其實都係一部電腦!

其實現代的streamer/NAS 本身並不是一部普通行Windows的PC, 軟體方面佢哋係用所謂Audiophile Linux的os, 硬件當然亦對音質有一定的要求，反觀Windows基本上是一封閉的系統，能優化的地方不太多，尤其在streaming real time protocol 方面，所以近代需要接駁DAC的音響系統多以行Linux為主，亦叫RTOS front end processor，例如發燒友喜歡diy的樹莓派Raspberry pi系統，而Windows/ios/android 等apps因繪圖靚，所以只被用來作MMI。

無論有冇localized嘅噪音，調好電腦嘅設置都一定有好處嘅

問題係，這些噪音，會否影響個別 listener

如果冇，梗係唔好搞咁多嘢啦

如果感覺可能有，甚至有，學多一點點其中一個解決問題嘅策略都好

在這兩個月我已經收集咗二百幾G 我喜歡嘅音樂檔案

開始探討

其實NAS或Streamer等等都係一部PC，之所以寧願搞好一部PC做CAS就係了解當中太多變數影響聲音，多幾件嘢搞比你搞到幾好都係將HD中音樂數據無損傳到DAC，不過如果要將音樂檔案上network的話就要用NAS，這時你感到NAS出嘅聲靚過你用PC出都唔等於這是必然，唔同嘅PC setting已經可以完全唔同，可做的只可以在自己條件中盡量優化。

可以分享這個一頭煙的經驗嗎?
覺得唔好聽？以及換了其他辦法就一天光曬的感覺？

在這裏分享經驗很好的

其實我用過舊的SSD, 2.5"HDD even 3.5"HDD on Qnap and Synology NAS.搞一大餐仍不能坐定定聽歌!

Irrigated hearing perception by all means it is not an electrically or safety wise concern for discreet hi fi listener

By all means it is not classified as degrading any function too for those emi etc..compliances

It can irrigate our hearing perception

Even those it is really have all those necessary compliances ,it does not affect any other piece of electronic function wise etc..

This is one way to look at it





最後修改時間: 2025-09-11 22:33:28

問左Ai佢咁樣答，安心使用了!
What Is EMI Radiated Emission?

EMI stands for Electromagnetic Interference, and radiated emission is one of its two main types (the other being conducted emission). Radiated EMI refers to:

- Electromagnetic waves emitted into the air by electronic devices during operation.
- These waves can interfere with nearby electronics, potentially causing malfunctions or degraded performance.
- It’s a key concern in EMC (Electromagnetic Compatibility) testing, which ensures devices don’t disrupt others or get disrupted themselves.

Think of it like invisible noise your device is shouting into the air—if it’s too loud, other devices might get confused.

---

？ Will It Happen on an M.2 SSD?

Yes, it can happen, though typically at low levels. Here's why:

- M.2 SSDs are high-speed storage devices that use fast data transfer protocols like NVMe over PCIe, which involve rapid switching of electrical signals.
- These fast transitions can generate electromagnetic radiation, especially from:
- The controller chip
- Power regulation circuits
- High-speed data lines

However, most M.2 SSDs are designed to comply with EMI standards (like CISPR 22 or CISPR 25). Manufacturers test them in shielded environments to ensure they don’t exceed safe emission levels and still function properly under EMI exposure.

---

？️ How Is It Managed?

- Shielding: SSDs and motherboards often include shielding to contain emissions.
- PCB layout optimization: Minimizing loop areas and using ground planes.
- Compliance testing: Devices undergo radiated emission tests in anechoic chambers to meet regulatory standards.

So unless you're designing hardware or working in a sensitive EMI environment (like aerospace or medical), your M.2 SSD is unlikely to cause any trouble.

但有好多師兄都認為呢隻鬼是相當可愛的，那1kHz 本身的諧波令浪漫派發燒友以為聽多好多音樂味，空氣感和微動態感等等，這也無可厚非，自己認為好聽咪得囉！

其實用非常普通的儀器亦可察覺兩者分別的確非常大，下圖上部份是一個1kHz 的Tone 放在NAS, 下圖是這個Tone 放在pc, 放pc 那邊的諧波足以令人身心煩噪！

其實好多情況就算撞鬼都唔知的

直至有啲機緣巧合，時間多了，做了一些行為，聲音變好了，是驅鬼成功還是心理作用等等？

探討原因，都是這個興趣的一部分

#257, 其實師兄說的呢隻鬼係來自HDD或SSD本身的EMI emission, 尤其SSD, 因本身有所謂的wear leveling algorithm，需要高速轉變memory cell addressing, 所以産生的emi radiated emission是非常嚴重（下圖)，HDD本身有Motor EMI noise。

我自己的streamer 本身可以裝hdd 或ssd，亦發覺 hdd/ssd 裝在NAS 那邊聽感會好得多，部份原因亦由於NAS 是放在另一房間，不同的mains socket 和grounding, 令emi noise 不會影響DAC, 當然系統是複雜了：NAS digital signal 要經LAN switch，亦有師兄用光纖/光隔等做emi isolation. 如此setup是很容易地同一部pc 接hdd, 用foobar 聽歌作出一個ABx 比較的。