其實 DigiPi 的淘寶賣家（百萬兄）還有製作這 USB 光纖隔離處理器，雖然 USB 3.0 → USB 2.0 的長芯盛 U3TT 與樹莓派 4 並不相容，但是原生 USB 2.0 的話或許是比較可靠？作者: sam0402
https://item.taobao.com/item.htm?id=637015014400
http://www.headphoneclub.com/forum.p...e=3#pid5276140
光纖USB之神奇網線隔離跟USB3.0隔離類似，不同方向的信號是分離的，USB2.0隔離的原理跟3.0隔離都根本完全不一樣
http://www.erji.net/forum.php?mod=vi...ad&tid=2218628
底部（紫色的 BW 4）就是加上百萬兄的產品，效果跟 USB 直出（藍色的 PC）不可同日而語：感受：微動態和層次感得到了全面提升，彷彿看三維立體畫看出了立體影像的那種鮮明感，聽音樂猶如開了上帝視角，各種細節盡收眼底。
微動態之妙，沒感受過真是無法想像，百萬光纖USB讓我的系統表現說是脫胎換骨也不為過，整整提升了一個維度。彷彿拼圖拼上了最後一塊然後魔法生效了！
https://www.l7audiolab.com/f/usb-5v-measurement/
https://audiophilestyle.com/forums/t...omment-1113294
然後把它連接到 IanCanada 的 BridgePi，再加上 Amanero384 介面就可以同時滿足 optical isolation 和 reclocking 兩個願望：
https://github.com/iancanada/Documen...pters/BridgePi
https://audiophilestyle.com/forums/t...omment-1108274
另一方案（不需要 USB／沒有 optical isolation 了）就是參考 Ericcatz 兄推薦的樹莓派電源淨化板，詢問那一位淘寶賣家（蒙娜麗莎兄）可否代為製作比較優質的延長線，作為淨化版的配套元件的話對賣家來說該是問題不大吧？
https://item.taobao.com/item.htm?id=633664880034
https://www.mobile01.com/topicdetail...&p=44#80972227
這是類似的 M.2 → PCIe 延長線，效果毫不遜色：
https://audiophilestyle.com/forums/t...-music-server/https://audiophilestyle.com/forums/t...omment-1012986This M.2 to PCIe convertor is another compromise. It would have been better to have a second PCIe slot. But I have tested bigger motherboards with second PCIe slot, and they did not sound better. That's why I am sticking to this well tested recipe.https://audiophilestyle.com/forums/t...comment-990193The overall result was better than the sound I got from the AsROCK X470D4U motherboard with the JCAT NET Femto connected directly to a PCIe slot. But to improve things even more, I replaced the cable with 24AWG 5N pure silver wires with proper shielding.如果還是有需要 Plan B 的話，可以考慮『沒屋頂賣場』的 Audio Reality / Yu-Studio 兄。I was able desolder the ribbon cable and solder my favorite 5N solid silver wire and shield it with JSSG360 shield. If there is any audible difference with that adaptor vs. connecting my JCAT Net card directly to the PCIe slot, I was not able to hear it. But I did not really spend much time on that A/B test.
最後就是關於價格方面的走勢，雖然銅並不歸類於金和銀那種貴金屬，但是隨著全球經濟復甦與及世界各國開始大幅發展綠色能源，價格只會不斷攀升：
https://www.lme.com/Metals/Non-ferro...per#tabIndex=2
https://www.macrotrends.net/1476/cop...cal-chart-data
https://www.spglobal.com/platts/en/m...-2021-analystsCanaccord Genuity mining analysts expect Chinese stimulus to support copper demand in combination with an expected global economic recovery in 2021.
"We now expect copper prices to average $3.50/lb ($7716/mt) in 2021, an approximate 17% increase on our previous forecast of $3.00/lb ($6,614/mt)," Canaccord said.https://orsted.tw/zh/news/2021/02/20...ability-reportCopper's long-term demand is backstopped by green energy and the push toward it, "as it is significantly more copper intensive than traditional, fossil fuel-based infrastructure," Stifel said. "We are updating our LT [long-term] Cu price to $3.40/lb ($7,496/mt). We believe a combination of short- and long-term market support in pricing."
This was echoed by Bank of America. "Given the increased focus on tackling climate change, the focus of government spending will be worth following as de-carbonization is bullish metals."
"Linked to that, we believe copper could once again rise above $10,000/mt ($4.54/lb) at some stage. What are the risks? Vaccine efficacy, delays to opening up economies and tighter monetary policy."https://tw.news.yahoo.com/全球轉向綠色能源-銅...100014237.html「我們必須在全球社會進行系統性且大規模的全面革新，才能創造零碳排的世界。」沃旭能源執行長麥茲尼博(Mads Nipper)表示：「我們要大幅增加綠色能源建置、加速淘汰以化石燃料為主的發電方式、在原本以使用化石燃料發電的產業拓展綠電使用，以及持續提升社會各個層面的能源使用效率。最重要的是，我們必須馬上採取行動。」看來還是先下手為妙?新能源車對銅的需求是燃油車的四倍，太陽能電池板和風力發電廠對銅的需求是煤、石油和天然氣等石化燃料發電的五倍。作為全球最重要的工業金屬，倫敦銅十二月十八日觸及每噸八千美元的七年高點，近幾個月已從三月份的低點攀升超過70%，推升銅價上漲的原因是庫存減少。
目前精煉銅產量約為2380萬噸，對再生能源基礎建設和電動汽車的需求不斷增長，將推動全球精煉銅消費量從二○二○年的2340萬噸升至二○三○年的3330萬噸。
根據已知的專案和估計的需求，並考慮到廢金屬的使用情況，預計到二○三○年將出現五百萬噸左右的供應缺口，這需要採礦業加大投資來填補。而這或許只是銅市的大多頭開始，隨著全球向綠色能源切換，對銅的需求預計將出現倍數增長。
銅庫存缺口上一次出現如此之大的差距是在二○○五年，當時銅價漲了兩年，今年的銅企業漲幅搶眼，美國礦商Freeport-McMoRan是全球最大的獨立礦商之一，其股價今年已上漲約90%，加拿大First Quantum Mineral的漲幅超過60%，滬深股市的江西銅業十一月漲了48.65%。
漲夠了嗎？高盛預計，在疫苗問世推動經濟復甦，二○二一年倫敦銅將挑戰每噸9500美元，然後在二○二二年上半年突破二○一一年創下的10170美元歷史高點。
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