Raspberry Pi 週刊 第十一期
July 04, 2018
本週店主會談談, Raspberry Pi 3對使用不同LAN規格時的影響。
不同Network Cable對音質有何影響？
當我們開始將我們的Raspberry Pi 3相關產品從AfterDark. daisyCAS, 到 AfterDark. audiophileCAS DTD時，旅程就開始了。店主開始問自己，Raspberry Pi3在音樂播放方面的潛力或瓶頸是什麼。是否可以 更換Network Cable改善音質?正如我們所知，過去使用CAT 5，CAT5e，CAT 6，CAT 7。不同的Network Cable產品方面有其規格，有不同的屏蔽方法和結構。您可能知道，Computer Science存在很強的爭議，Network Cable只是傳輸數字信號，意味著所有的數據傳輸都可以毫無差錯地完美傳輸。因此，兩者之間沒有區別。沒有理由，不同的網絡可以聽起來不同。但是，店主在Raspberry Pi3上試用不同品牌的網線時。在將CAT 5交換到CAT 6和CAT 7時，總會有很大的不同。因此，店主開始花費一些時間用一些不同的屏蔽材料，不同的插頭手工製作網絡Network Cable。然後，幾個月後，店主開始將最終產品發布, 給想試用的客戶。該產品在（CFS）碳纖維屏蔽技術市場上獨樹一幟。插頭採用特殊金屬合金製造，符合CAT 7規範。
店主記得首先發布這款網線，它非常吸引人的價格以0.8米長開始銷售。令人驚訝的是，我們在兩週內賣出了前50米。顧客問店主：那麼CAT 7網線的音質如何呢？Network Cable擺放哪部分更關鍵？該店回复說：向Raspberry Pi 3和Network Streamer的網線應該先換掉。從使用NAIM ND5 XS Streamer的客戶那裡收到了好評，使用AfterDark. Constrallation CFS CAT 7 Network Cable之後。就像換了前置放大器，聲音更加堅實和細化。更重要的是，線纜的聲音非常平衡。
顧客詢問店主：你如何使設計這Network Cable？我認為這只是Network Cable。這種衝擊對我來說非常震撼。店主：是的，大多數人都知道空氣裡總有一些無形的EMI和背景噪音，比如電路引線，移動信號，無線設備，我們發現Network Cable可能會吸收這種EMI noise 並傳輸到 Raspberry Pi3，DAC，Network Streamer。因此，我們嘗試使用碳纖維屏蔽（CFS）技術來阻止那些EMI noise進入電纜的信號路徑。其結果是更好的接地，隔離EMI噪聲。播放音樂時，您可以聽到更多細節，背景更暗。另一方面，EMI noise不會從您的network cable傳輸到DAC/Network Streamer，性能得到優化。客戶問：使用Telegartner CAT 7插頭時最有什麼好處？店主回答說：這是另一大改進。插頭非常重要，可為核心電纜和連接器提供剛性接觸點。 Telegartner CAT 7中使用的材料是專門設計的，可以為關鍵任務應用提供更好的聯繫，並可為發燒友用戶提供特別設計。您可以聽到更多茂密的高音，更好的聲場和更多的背景細節。關於技術的話題:
CAT 7和CAT7a概述
7類（Cat7）和7a類（Cat7a）是最新的電纜標準 以太網和其他互連技術。 Cat 7電纜是嚴格開發的 有關串擾和EMI保護的規格。 Cat 7電纜具有四個獨立的功能 屏蔽線對以及整體電纜屏蔽層以保護信號免受串擾 和EMI。 Cat7電纜為100千兆位以太網提供銅纜解決方案。
Cat7電纜通常使用連接器GG45連接器端接它向後兼容Cat6或Cat5e上使用的8p8c RJ45連接器電纜。 GG45連接器有四個額外的導體提供支持頻率高達600MHz，使用Cat7a高達1000MHz。越高頻率允許Cat 7電纜支持萬兆以太網。使用Cat7a電纜高達1000MHz。支持更高的能力頻率允許Cat7和Cat7a電纜承載更多數據。這允許Cat7和Cat7a電纜支持高達10Gb以太網的以太網應用Cat5e / 6有什麼實際性能差異？Cat7和Cat7a電纜旨在支持比Cat5e和Cat6更高的頻率信號。這使得Cat7和Ca7a佈線可以傳輸更多的信息。 Cat7和Cat7a電纜還能夠更好地保護通過電纜傳輸的信號。屏蔽以及更緊密Cat7和Cat7a電纜中的雙絞線減少了串擾和EMI的影響。Raspberry Pi Weekly No.11
What is the effect for Raspberry Pi 3 on sound quality with different network cable? The journey started when we start our Raspberry Pi 3 related product from daisyCAS, fusionCAS, to audiophileCAS DTD. The shop owner start asking myself, what is the potential or bottleneck of Raspberry Pi3 for music playback. Can we improve sound quality, when we enhance the accessory parts for just change the Network Cable. As we know, we used to use CAT 5, CAT5e, CAT 6, CAT 7. Different generation have their specification, different shielding methods and structures on cable twisting. You may know, there is strong argument in computer science, they are just digital signal, and implies that all data transfer is perfectly transmitted without errors. Therefore, no differences in between. There is no reason, different network can sound different. However, when the shop keeper try on different brand of network cable on Raspberry Pi3. There is always a big different when swap around the CAT 5 to CAT 6 and CAT 7. Therefore, shop owner started to spend some time to made some network cable by hand with some different shielding material, different plugs. Then after a few month time, the shop keeper start to release the final product to customer who want to try the first hand made network cable from AfterDark. The product is unique in the market with (CFS) carbon fiber shielding technology. The plug was made in special metal alloy, constructed according with CAT 7 specification. The shop owner remembered when AfterDark. first release this network cable, it was selling in very attractive price with length of 0.8 meter. Surprising we sold out our first 50 meters in two weeks time. So how is the sound quality in CAT 7 network cable?
Customer asked: Which parts of network cable is more critical?The shop replied: The network cable towards your Raspberry Pi 3 and Streamer should change first. We recieved a comment from customer using NAIM ND5 XS Streamer saying it is day and night different when changed to use AfterDark. Constrallation CFS Network Cable. It is like changed the pre-amp, sound is more solid and refine details. More importantly, the cable is very balanced sound. The customer ask the shop keeper: How you can made this network cable so special? I thought it is only a network cable. The impovement is quite shock to me.The shop owner: Yes, most people knows there always some EMI and background noise which is invisble to you, like electic circuit leadages, mobile signal, wireless devices, we found that the network cable may absorb or distorted by this EMI noise and get transfer to your Raspberry Pi3, DAC, network streamer. Therefore, we try to use carbon fiber shielding (CFS) technology to block those EMI noise to enter the signal path of the cable. The result is better grounding, EMI noise isolated. You could hear more details and the background is much darker when playing music. On the other hand, the EMI noise will not be transfer from your network cable to your DAC, and network streamer and hence the performance is optimised. Customer ask: What is the most benefit when using a Telegartner CAT 7 Plug?Shop owner replied: This is another big improvement. The plug is very important which provide the rigid contact point for core cable and connectors. The material used in Telegartner CAT 7 is special designed with better contact for mission critical application, and special dsigned for audiophile user.You can hear more lush treble , better soundstage and more background details.Technical Insight:
Category 7 and Category 7a Overview
Category 7 (Cat7) and Category 7a (Cat7a) are the newest cable standards for Ethernet and other interconnect technologies. Cat 7 cable was developed with strict specifications on crosstalk and EMI protection. Cat 7 cable features four individually shielded pairs as well as an overall cable shield to protect the signals from crosstalk and EMI. Cat7 cable provides a copper solution for 10-Gigabit Ethernet at 100 meters.Cat7 cable is commonly terminated using a GG45 connector, which is a connector that it backwards compatible with the 8p8c RJ45 connectors used on Cat6 or Cat5e cable. The GG45 connector has four additional conductors that provide support for frequencies of up to 600MHz, and up to 1000MHz using Cat7a. The higher frequencies allow Cat 7 cable to support 10-Gigabit Ethernet. The ability to support the higher frequencies allows Cat7 and Cat7a cable to carry more data. This allows Cat7 and Cat7a cable to support Ethernet applications up to 10-Gigabit Ethernet
What’s the practical performance difference with Cat5e/6?Cat7 and Cat7a cable are designed to support much higher frequency signals than Cat5e and Cat6. This allows Cat7 and Ca7a cabling to carry a larger amount of information. Cat7 and Cat7a cable are also able to better protect the signals traveling over the cable. The shielding as well as the tighter twists of the pairs in Cat7 and Cat7a cable lessens the effects of crosstalk and EMI.
