同軸線問題

jasonhh

想請教:
TV用的 75ohm同軸線是否(配上RCA頭后)適用於audio 的"Digital coaxial output"之同軸線??
e.g. CDP ---> digital coaxial output --> INT AMP

定還是係兩種唔同的線材??
小弟無知,盼能得ching 賜教

colorp

理論上可以。
實際上起網上亦見唔少人用 Belden 1394a for TV 同digital coaxial interconnect。

jasonhh

理論上可以。
實際上起網上亦見唔少人用 Belden 1394a for TV 同digital coaxial interconnect。 ...
colorp 發表於 2011-4-27 13:36

    thank you colorp hing! great!
i'm thinking of using my old Hitachi LC-OFC TV coaxial cable to DIY as coaxial interconnect for CDP-> INT AMP for the system in my mother-in-law's house
咁請問實際上呢兩種用途的同軸線,規格要求有冇不同 (except for the connector)?

colorp

大家都係75ohm RF，規格要求有冇不同？我覺得最大不同可能係因應使用上要求而有分別。

例如TV通常傳輸距離會遠（天線到入屋），又可能係戶外用（村屋？），所以損耗要低之餘又要抵禦風吹日曬同拉扯，可能會較粗同硬。S/PDIF 通上係室內用同相對短，所以可以用軟一點o既線。

TV線bandwidth要求係GHz來計，S/PDIF只係MHz。但我估無人會怕 bandwidth 太闊。

jasonhh

大家都係75ohm RF，規格要求有冇不同？我覺得最大不同可能係因應使用上要求而有分別。

例如TV通常傳輸距離 ...
colorp 發表於 2011-4-27 14:19

    thank you very much for your detail explanation!

colorp

順帶一提，造SPDIF 線，條線唔好短過 1.5m。

jasonhh

順帶一提，造SPDIF 線，條線唔好短過 1.5m。
colorp 發表於 2011-4-27 14:31

i see!
is that because of the bending problem if the line is too short? or any other reasons?

sunboy

順帶一提，造SPDIF 線，條線唔好短過 1.5m。
colorp 發表於 2011-4-27 14:31

    C Hing, may I know the reason please ?

colorp

老實講，小弟無自己做過比較。
不過網絡上有唔少人都係咁講。我覺得除非可以唔用線，否則信下都無壞啦。
http://www.positive-feedback.com/Issue14/spdif.htm

sunboy

Thanks for C Hing's technical reference.........

I did have the experience of comparing two digital cables of the same model with 1M & 1.5M with a number of friends and we all found that the longer one always had a better sound than the short one. If we ignored the cost and the inconvenience of using long cable in short distance, please select the length of 1.5M to play safe for better sound instead of using the shorter length..........my 2 cents only