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?
Hi -

Yes, that is a logical assumption. To the best of my knowledge, no mass-produced cassettes used Dolby C. Dolby "C" and "HX-Pro" were found on many cassette decks, but never caught on in the prerecorded market. I also believe there was a Dolby "S" that came out just before the cassette's downfall began.

It has been my experience that using Dolby B or C takes more than noise away. It also dulls the overall sound. If you listen at higher volumes the Dolby helps to remove the hiss. But you mentioned "quiet background music". If listening to lower volume levels it may sound better to turn the Dolby off.
I agree, dolby off at low volumes, you be the judge at higher levels, B,C might take away fatigue.
Every prerecorded cassette that incorporated Dolby noise reduction should have a Dolby logo/marking on the tape or the box. As I recall there were many prerecorded cassettes that were made in Dolby B, but I never saw any prerecorded tapes in Dolby C. I personally recorded many cassettes in Dolby C from material off of CDs. I had excellent results, especially when using high-bias blank tapes.

To address your question, you should not assume that prerecorded tapes are Dolby B unless they are marked as such. In any case, if the playback sounds best to you with the Dolby B switched on, then go ahead and listen that way – you won’t hurt the tapes.
If the tape is pre-recorded and marked Dolby, it is Dolby B. Dolby C was available to consumers while recording their own tapes, but was not used on commercial tapes. As it has a more agressive EQ curve for encoding and decoding, it will make the prerecorde3d (Dolby B) tapes sound duller if used on playback.

Dolby HX Pro is a playback only processing and is not, to my recollection, usually selectable.
The tapes are plainly marked "Dolby" but no indication of B or C. I guess B is the right answer.
Definitely B.

But Dolby C, on a good deck, with a good tape, was a real treat.
The question about whether the commercially available tapes were Dolby B or C encoded has already been answered correctly by many on the thread.

In my opinion the best way of getting the benefit from the dolby encoded disks was to record and listen on the same deck especially when it is precisely caliberated for playback and recording. The commercial tapes had variations, some sounded really good and some not really so.

I still have about 100 or so left with me from long time ago, and some sound pretty good. The TDK SA (High bias CrO2) and AD (Normal bias Fe) were the best in my opinion not only for the time but in terms of longivity. The SA and AD were my preference always.

I still have the Nakamichi 700 with me but it needs a bit of cleaning as I have had no time to do that.

I used the Nakamichi 700 Tri-Tracer for a very long time, my friend had the legendary 1000, it was good old days I must say the best times I spent really enjoying music with almost no resposibilities or worries.

Thank you for creating this thread, it sure brought back memories of the good times :-)
Everyone gets bent out of shape about copy protection which prevents the making of digital copies. The easy way around this is a good analog recorder of some kind, or even a digital recorder which accepts analog inputs.

Further to that point, I always found it curious - as an audiophile - to think that in the late '70s to early 80's, tape decks could make great recordings that were virtually indistinguishable to the original. (At least for laymans', if not golden ears.)

But it was "digital", which didnt even sound as good, that drove paranoia and copy protection to new, ridiculous heights.

I guess the Napster police have never heard of Nakamichi?
I own a Yamaha cassette deck with Dolby B&C, which I purchased in the mid eighties. It's a mid-fi deck...certainly not high end, but also a step above consumer (I think...).

I used primarily TDK SA tape, with an occasional Maxell thrown in.

Talk about making digital sound like analog! Good Dolby C cassette recordings of CDs still sound wonderful, in my opinion.
All this talk about, TDK, Nakamichi, Dolby has brought back fond memories, I think I am going to service my Nakamichi this weekend :-)
I've looked at the Nakamichi Dragon's listed for sale as if they were puppies in a pet store window, until I've been brought back to earth by reading of the service/reliability issues with this particular cassette deck. But, they sure look nice!

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?

In my opinion the best ones were CR7A and 1000, the Dragon was a top deck but tempermental.
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?

I can't tell if this is a serious question, or one written tongue in check, but I'll answer honestly.

In my opinion, analog cassette recordings do round out the CD sound and slightly soften the high frequency fatigue. I like the results.

With my Yamaha deck, and using Dolby C encoding and TDK SA tape, there was VERY little tape hiss. In fact, I'd say nothing more than one can hear on almost any above average quality CD made from original analog source tape.
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.
Isn't it funny that recording CDs on casette tape seems to give 'better' or more satisfying sound, yet digital 'dissers' claim that the reason for digital's poorer sound is the LACK of information (overtones, microdynamics, etc.) contained in that medium. Are we saying that analogue recordings of digital recordings restore information or just introduce distortions that are pleasing?!! 'Rounding off' the highs seems like losing even more information.
Bob P.

I was not being tongue in cheek.

Bob P

I think both of those statements can be true.

To my ears (as a digital "disser") CDs

1) accentuate frequencies - or add information? - that I find fatiguing.

But at the same time, digital often has

2) an absence of certain spatial cues, harmonic overtones, richness and depth.

In the case of a CD archived on a tape, I see no reason why the tape can't improve on point 1) and perhaps sound better.

Obviously, it can't create the missing info from point 2.
One audio writer, years ago, described the low noise of CDs as a silence of absence, not a silence of presence.

Nonetheless, perhaps the noise of analogue is in some way creates a better illusion of that, even with the information that was "missing" from the CD.
Cwlondon, you might enjoy experimenting with recording your CDs to cassette tape using a good Dolby B/C cassette deck and high quality tape (like the TDK SA). Cassette decks are dirt cheap these days...probably less than a jar of contact enhancer.


Yes, maybe I should scrap this high end, WAV file music server idea, and just move my entire CD collection to cassette tapes.

I do think that would be an improvement!
Server, shmerver. Go low tech. The drive will eventually just crash anyway.

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.