剛剛查了一下 Audio Archive Inc. 的STUDER A820的資料* E! `- P, x& D7 Z, P3 `" c. c
http://www.theaudioarchive.com/TAA_Tape_Studer_A820.htm; d7 |4 n+ V1 D
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其中有一段是該公司提供的內容:" p& q; K, T( J& V8 b
The Audio Archive: There are only 3 STUDER machines that have the skimming capability: STUDER A820 MKII, A812 MKII, and A816. Studer was the only manufacturer to build this capability into their machines. Note that print-through erasure was patented by R. Herr of 3M (US Patent 2861133, filed 1949 Aug 01, granted 1958 Nov 18). In essence, skimming works by erasing the printed field in the smaller improperly oriented oxide particles on the tape, while not greatly affecting the field recorded in the longer, properly oriented oxide particles. Hence it only works on the original tape. Because it works via magnetism, it would be extremely difficult, if not impossible, to implement skimming using DSP.
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& |9 a+ ^! N. J我還在揣摩這個"Skimming"的功用,STUDER的機器只有A820 MKII, A812 MKII, 及 A816這三型有此功能,而此功能又只有STUDER的機器獨有!4 ^# z- G5 z& `
" J7 N* ~% \/ P) l2 I似乎跟R. Herr美國專利號2861133的發明有關,這個發明的內容在減少磁帶卷帶後相鄰磁帶層轉錄的現象。
' [ l! K/ _2 T' N這種模式會在放音時在抹音頭提供弱的抹音電流或偏壓電流,可在犧牲少許錄音內容的狀況下大幅改善磁帶層轉錄的現象。
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