More Dolby input questions

[Menchi]

A friend has given me his old cassette deck ( although 8 yr old, it's much better than mine ) on the promise that I will restore some cassette tapes for him.

The tapes were recorded on this deck, which has Dobly B and C.

I am trying to work out if the tapes were recorded in Dolby B or C - my friend can't remember.

1. Playback without Dobly - very loud hiss
2. Playback with B - slight hiss
3. Playback with C - almost no hiss.

If I playback the tape on other equipment there is some hiss, although not as loud as 1. above. I have read that Dobly B gave much better playback than C on non Dolby equipment, so these tapes could be Dolby B. ( I wonder if a Dobly B tape would actually sound better if played back via Dobly C? )

Assuming that I correct in my assumption that the tapes are Dolby B, what setting have people got the best results with, when tranferring to PC - Dobly B or Dolby off. Or maybe even C ???

Is there a definitive answer, or is it "sniff it and see" - variable by tape and noise level?

I read the Dolby threads, and tried no Dolby, and B, for a comparision. The Dobly B seemed to give a cleaner result although occasionally there seems to be very slight distortion in spoken vocals, but maybe I've not got the settings right yet ...

Any help is welcomed !!

[Lord Theo]

My best results are obtained with ALL noise reduction turned off & as much tape hiss as possible removed with CNF or EZClean without introducing artifacts.

[Craig Maier]

Lord Theo has a good approach for Dolby B tapes. I have never tried that with a Dolby C type.

But if you want to know if your tapes are Dolby B or Dolby C, it will be kind of obvious when you perform the following test. If you play a Dolby C tape on a tape deck with all Dolby Noise Reduction turned off, it will sound quite shrill and will also produce a high frequency "pumping" sound. It will sound almost unlistenable. If you play a Dolby B tape on a tape deck with all Dolby Noise Reduction turned off, it will just sound bright and a little hissy and still be listenable.

[Menchi]

So, Dobly B they are, and record with no noise reduction.

My thanks, Lord Theo and Craig