Cassette Tapes..Dolby B or C?


I still have a tape deck in my system, and have a few tapes that are nice for quiet background music. The tape deck has a switch to select Dolby B or Dolby C (or none). There seems to be no marking on prerecorded tapes to indicate the type of Dolby processing. On a tape I was just playing B sounds about right. Should I assume that all prerecorded tapes are B unless otherwise stated?
eldartford
The Dragon is a great cassette deck, but like expensive cars, you have to be willing to spend money on getting it up to spec and periodic maintenance. Once I got my machine working perfectly I have not needed service for over 2 years, and it gets a lot of use.
WOW! I never thought that this thread would draw so much comment. I just had a simple question. I guess it is a little-known fact that some audiophiles still like their cassette decks.
Dolby B incorporates a bit diiferent type of noise reduction then Dolby C.If I can recall on my old Marantz 4400 Receiver,Marantz would calibrate the receiver on Dolby B recording with a 400 HZ test tone.Dolby C elavates the noise band reduction up to the mid to upper mid band frequencies.Thus the noise reduction would be more beneficial in the upper band frequencies.In general Dolby B may reduce noise by 3 to 6 DB,and Dolby C may reduce noise by 10 to 12 DB at certain particular frequencies.
Nakamichi Dragon and other top of the line cassette players also utilize built in computers to auto bias the tapes for maximum noise reduction as well.