On 05/01/06, Tom Fine wrote:
Another big problem in my own cassette collection is what I call Dolby C deterioration. Apparently, Dolby C is very sensitive to level in order to decode correctly. Level seems to fade over time on many tapes I made in the early 90's -- generally on Maxell and TDK chrome C-100 tapes. Dolby C is not happy with this and the sound results are not good. Whenever possible, I have re-borrowed that material and made CD copies. Dolby B doesn't seem as unhappy by level fades over time.
There is a need for a software decoder for Dolby B and C, with adjustments for dealing with such problems.
But even in the 1980s, I used to find that a Dolby cassette played back on a different machine did not always sound right - it seems the circuits were often badly adjusted in manufacture or had drifted.
C is of course more fussy than B.
Regards -- Don Cox doncox@xxxxxxxxxxxxxx