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
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Tvad

It rounds the CDs and softens the high frequency fatigue?

And throws in the tiniest amount of tape hiss - enough to get sentimetal about analogue?
Tvad,

In my opinion the best ones were CR7A and 1000, the Dragon was a top deck but tempermental.
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In the generation of master tapes DBX processing beat out Dolby. The DBX processors available to amateurs at a reasonable price were less sophisticated, and comparable to Dolby. I used one for a while. In the world of master tapes it was also noticed that running a recording made by other means through an analog tape recorder made it sound better. About 30 years ago I could give you the reason, but those gray cells are gone.