尋找音樂播放器

hkborn

尋找音樂播放器

音源一直是音響系統重要的一環。
人人都說黑膠好，但黑膠已經是歷史產品，舊的黑膠因時間損耗而失真，新出的黑膠錄音大都是數碼錄音，說黑膠比CD好或CD比黑膠好很多時是蘋果與橙之比。原始錄音是模擬的，黑膠一定好聽；原始錄音用數碼，那CD自然較好。瞭解這點以後，就放棄用黑膠的念頭，免得為日益稀少的音源煩惱。
將焦點放在數碼錄音，皆因在可見將來數碼錄音仍是主流。


數碼播放的正統是CD機，差不多三十多年了，CD機也在不斷進化。CD，DVD，HDCD，SACD，無論怎樣變，CD機一直被認為是聲音最好。隨著電腦軟硬件火箭式發展，CD不再是音樂檔案唯一儲存點，CAS也乘勢而起。如果回看歷史，Linn全面停產CD機，但仍保留黑膠盤，可算是里程碑。保留黑膠，主要是黑膠盤仍然是模擬技術的必需品；放棄CD，是因為CD唱片已過了巔峰期，以後只能走下坡。Linn 認為 music server可全面取代CD機，所以推出Linn D/S，音樂權案也由小膠片改為網上下載，格式由16bit 44.1kHz 至24bit 192kHz都有。

要說CAS全面超越CD有點為時過早，但這是時間問題而已！基於此，投資CD機似非明智之舉。因此，考慮音源系統還是以選擇播放器及解碼器最具前瞻性。

解碼是數碼播放的核心，有機會再談，先說播放器。

播放器組成有軟件及硬件兩部份。軟件即程式，硬件為執行程式的電子線路，而電源作為電子線路的血管，當然是要重點關注。

軟件的執行要在操作系統下進行，現時個人系統主要是Windows及Mac O/S, 非主流的Linux在加入桌面後也開始為人接受。CAS的起始就是從桌面系統的音樂軟件帶動。Window自帶的window media及Mac的itune 到現在仍是主流。兩者操作方便，音質卻不盡人意。要求不高的沒有所謂，要求高傳真的就各出奇謀。操作系統原來的設計是多用途，眾多程序的執行次序並非以音頻為先，於是音樂軟件如雨後春筍紛紛湧現。軟件質素高，硬件卻仍是大問題。當意識到播放音樂不需高規格硬件，很多人就將電腦作為專用播放器，以減少其他無用程序。但是，無論windows或Mac都是巨無霸操作系統，如何能有真正精簡呢?桌面系統只是好看易用，卻對音質無助。理論上，愈是簡單直接的指令程式，是最好的播放器軟件。所以，window 和Mac先天不足，再好都要打個折扣。Linux優勢明顯一點，用terminal command最簡單，只是難為了一眾離不開使用圖案的用家。

接觸過不少播放器，最欣賞是MPD(Music player Daemon)。它既是播放器，也具備伺服器功能，它以指令形式存在，我們看不見實體。使用MPD要透過client介面，如web browser 或mobile app來操控，前提是大家在同一網絡。這樣就變得很有效率，原理跟UPNP相似，播放器與操控介面用不同工具可減少對硬件負荷。當然，現時Linux派別繁多，桌面系統如ubuntu也愈見複雜，也有多餘程序，所以用最細小的操作系統最好。Voyage就是非常簡潔的小操作系統，與MPD真是天作之合。所差的還是硬件，現時網站建議的底板不是為音頻而設，仍有很多不足之處，話雖如此，其他的缺點更多。所以我還是覺得voyage mpd性價比最高。

就是這些種種不足，令很多人對CAS裹足不前，特別是老一輩發燒友，最怕用電腦，效果又不好，更不相信1010的數字可以做出有感情的音樂來。CD永遠只是老燒友的次選，是無可奈何的折衷。CD機最大優點是單一功能，閱讀CD片的資料及解碼，更精細的將解碼部份抽出，稱之為CDTransport。當解碼可以獨立出來，CD機也差不多走到產品週期的最後一程。這看法當然會引起爭議，但不爭的事實是CD機只能讀取CD片的資料，不能滿足音樂檔案網上下載的趨勢，它的功能完全可以由電腦或音樂播放器取代，當然，CD機此刻仍然因使用習慣佔優，但往後它不會像黑膠般仍能佔據獨有的市場地位。

除了Linn D/S，市場上湧現種種播放器，基本上是優化板的電腦。硬件在於選擇處理器，軟件是運作系統，播放器大多自行開發。MPD是現成的，不少播放器用其作為核心，最早的是Bryston BP1，之後araliti, W4s。值得一提是Squeezebox Touch，其實是理想的大眾化播放器，可惜被大公司收購後創意就沒有了，其主要問題是配套的squeeze server太臃腫，相信在停產以後，很多用家仍會繼續使用。Sonos 其實相當不錯，在香港不為接受，外國則頗多mod。從德國訂了一個回來，果然名不虛傳，操作方便，現時放在家中使用。

一次偶然網上溜覽，發現了SDTransport 384，它設計核心思路是用最少耗電量的硬件和軟件。處理器是只有8-bit 的MCU (Silicon Labs 8051)，程式用FPGA: Cyclone III (Altera) 設計。晶振是來自NDK，一家專門生產晶振的日本公司，好像是為此而特製的，據稱是ultra low jitter。程式是自己開發的。在電路上的設計，整個線路只需要5V (+/-5%), 0.5A 的電，有能力DIY的話，更可更準確的為個別元件供電：



  1.
    1. External power supply connection [CN1, CN5, CN7, CN10, CN13 ]
SDTrans board has five DC power circuits, + 3.3 V x 3, + 2.5 V x 1, + 1.2 V x 1. Through these connectors, you can provide external DC powers instead of using internal power lines.
The necessary voltages and draw current are given on the table below. (Please remember that the maximum draw current values are tentative and might be revised in the future.)
CN # Voltage[V] Allowed Voltage range [v] The maximum draw [mA] Circuits connected
CN1    3.30          2.97 - 3.63                                 50                         Clocks
CN5    3.30          3.00 - 3.45                                150          Micro processor,Memory card
CN7    3.30          3.14 - 3.45                                150                      S/PDIF、I2S
CN10  2.50           2.375 - 2.625                            50                           FPGA
CN13  1.20            1.15 - 1.25                              100                         FPGA

它另外一個特色是能處理PCM及DSD檔案，要留意是原始DFF，不是DFF轉成PCM。這功能仍未有機會使用，因為能為DFF解碼的dac很少，接口用I2S也沒有標準。無論如何，就算只播放16bit 44.1khz的音樂，已有很高水準。SDCard 比硬盤好是沒有接口及電源問題，usb接口也有處理電的煩惱。至於音樂檔案的格式，只支持wav，這又是慳電的原則使然，如果用flac，多了一重轉回wav的程序，用電會浪費。8 bit處理器，只支持英文字母及數目字，中文日文欠奉。

在跟日本人討論這貌不驚人的小東西的時候，提到現時主要用來聽CD red book format，日本人說這是暴殄天物，如果只聽CD，他介紹我用Chinese 的QA350或QA550。後來發覺日本人對中國人的音響產品非常捧場，很多日本發燒友都有用QA350!另外是voyage mpd starter kit，他們更有論壇討論voyage mpd，談得非常深入。

日本高手推薦下，自然要一看究竟。很快就發覺其軟硬件理念符合自己要求，雖然美學水平不敢恭維，但音質卻有驚喜。它最核心優勢是用單片機寫程序，單片機是自家開發，要多少RAM, ROM,I/O都可以。真正是tailor made 的處理器。

寫到這裏，剛剛看到一則關於Linn的新聞，可以一看，QA產品下回分解。

http://www.heraldscotland.com/bu ... fits-surge.19281748

HIGH-end music system specialist Linn achieved a 21% hike in pre-tax profits to £2.19 million in its last financial year to June 30, as it enjoyed strong demand for its cutting-edge digital streaming (DS) players in tough economic conditions.

Gilad Tiefenbrun, managing director of East Renfrewshire-based Linn, revealed that Hollywood actor Michael Fassbender had purchased one of the company's DS music systems recently.
Linn, which is based at Waterfoot, enjoyed a 5% rise in turnover to £17.3m in the year to June. It employed 173 people at its June 30 year-end, Mr Tiefenbrun said, with the company having recruited "cautiously" in the last two or three years.
Linn said yesterday that its decision to exit the compact-disc player market nearly three years ago had "raised eyebrows in the industry". It added that its focus on high-resolution music downloads played back on Linn DS network music players had been "vindicated by these financial results".
Mr Tiefenbrun noted the value of Linn's sales of DS music players was now close to past peak annual sales of CD players.
He said: "Where we are with the streaming is up to where we were at the very peak of CD, and it is early days in streaming. We see tremendous potential with streaming. It is an area where there is actually growth. People moving from CD to streaming is still at the early stages."
He emphasised Linn's heavy investment in continuing development of its DS players. He said the company had invested £2.15m in research and development in the year to June 30.
Noting that Linn had started making DS music players in 2007, he added: "Because it is all our own technology, we are able to add into that with R&D."
He cited a new range launched in the last year which could play "sound from just about everything you can think of in the living room", including television, movies, and games as well as music, through HDMI (high-definition multimedia interface) connections.
Mr Tiefenbrun cited these DS players' compatibility with personal computers, iPods, iPads, and Android devices.
He said the typical price of a Linn system was between £5000 and £6000, with the starting price of a pure music-playing system about £1500.
Linn continues to make vinyl record players. Mr Tiefenbrun said this part of the firm's operations was "pretty stable" at 10% to 15% of the overall business.
Asked if he was pleased with Linn's performance given the economic backdrop, Mr Tiefenbrun replied: "I am absolutely delighted with these results.
"I think we are doing way better than anyone would have predicted. We are not immune to the conditions out there. It is driven by innovation.
"We have to stay at the absolute forefront. We have to be out there competing."
He added: "I think, overall, there isn't a huge amount of growth in the markets. We have to win market share. We just have to get used to having to fight like everyone else.
" You can't rely on there being some kind of miraculous upturn in the economy."
Mr Tiefenbrun highlighted the troubles in the eurozone, which he described as a "very significant market" for Linn.
He added: "We are just assuming things will stay the same. These are the market conditions, and we need to compete in the market we are in."
Linn also records music. Linn Records is home to artists including Carol Kidd, Claire Martin, and the Scottish Chamber Orchestra. Mr Tiefenbrun said Linn Records accounted for 5% to 6% of group turnover.
Gilad's father, Ivor, owns more than 60% of Linn. Ivor's brother, Marcus, has a minority stake. Ivor and Marcus's sister, Bessie, owns about 1.5% of the firm.