Dolby introduction on cassettes

[Ekcoman]

I'm trying to work out when Dolby became standard on pre-recorded tapes. I'm guessing 1974 as have two Pink Floyd Cassettes one 1973 without DB and one 1975 with.
Seems some cassettes are now becoming collectable anyone throw any light if there is any truth to this?

[electronicskip]

I am thinking your guess would be correct.
Dolby B was available from the mid 70s for commercial grade prerecorded cassettes.

[Ekcoman]

Looking at some other pre-recorded tapes of Philips they weren't using the Dolby Logo as late as 1976.

[paulsherwin]

There is currently a fad for cassettes among the young and fashionable. It probably won't last long, but then that's what I thought about the record player craze.

[Ekcoman]

Bit like the inflated prices being paid for pre-recorded reel to reel tapes. Makes no sense but retro is big in many very unpredictable ways.

[Synchrodyne]

The forthcoming availability of Dolby'd cassette recordings from some labels was announced in 1970 third quarter:



So perhaps some such were available by 1971?

But the general changeover may have taken a few years.


Cheers,

[PWH]

I have "The Man Who Sold The World" David Bowie RCA PK-2103, which I bought new in 1972 and it is not Dolby

[TIMTAPE]

This Wiki page says Dolby B was introduced in 1968 but doesnt say when record companies started releasing cassettes with it.

https://en.wikipedia.org/wiki/Dolby_...duction_system

[Trevor]

I used to be in the hifi trade Phillips had their own system DNL Dynamic Noise limiting in the very early 70,s
Tapes could be purchased as both Dolby and non Dolby as a lot of the early machines did not have this feature To be honest it was never my favorite format to noisy and limited freq range and the cassettes were always snagging - de spooling give me an LP every time
Trev

[Restoration73]

Cassettes (and VHS) are only collectable in as much there may be rare material not on
later formats.
My "BIB Hi-Fi Stereo Test Cassette" dates from 1972 and is Dolby B (produced by Decca) and the calibration levels are still good despite being a Type I ferric tape.
There are too many variables for calibration in domestic cassettes, the medium only becoming serious with the advent of Type II and Type IV tapes i.e. CrO2 and Metal.

[stevehertz]

Anything is "collectable" if people want to collect them. Take myself, as usual my vintage wireless/hifi interest goes round in circles, and one of my main interests is currently cassette machines. As part of that interest I also look out for pre-recorded cassettes of my favourite albums. It's not against the law to get enjoyment out of fag packet size, neatly packaged music tapes with nice printed covers. And yes, the quality is usually poorer than if you recorded your own using a high quality tape on good equipment. Again, that doesn't make it wrong or pointless, it just highlights the joys of 'vintage audio' and how we gain enjoyment from such items regardless of whether they are the best option. That's what it's all about, the enjoyment of all things vintage wireless, audio and video, warts and all. It's not for anyone to pour cold water on the specific interests of others.

On the subject of pre recorded cassettes with Dolby, to my knowledge Dolby was never taken up universally. You can find late cassettes that are not Dolby encoded.

[mark2collection]

I have a tape from the mid-80's which isn't Dolby, but then it was 'chart' music & I was only 10, and didn't know any better.

My Father has a small selection of tapes, from memory the mid to late 70's releases were mostly Dolby.

I'm still laughed at for using a DAT recorder & until fairly recently, Minidisc and 8-Track, which have since been sold (lack of use & the buyer was REALLY into them). Plus I still have a very early piano-key VHS machine & a Betamax.

They don't laugh at my old record player, my apparently 'funky' battery portables (Hacker Sovereign II & Roberts R707) the Ekco A22 or my hand-me-down-from-childhood, Raleigh Chopper.

As fashions change, so it would appear others' ideas of comedy value. The recorded player a few years ago was seemingly hilarious to own, being, out of vogue

They don't laugh at my car now either, since it has reached classic car status ('88 V12 XJ-S), but their we are, a new social circle helps too, as we move through life, & the 'young funkies' get left behind, with their ruined up-cycled lamp worth nowt, which was once a mint Singer sewing machine (for example).

Anyway, my main tape 'deck' is a Nakamichi CR2, early 90's I believe, with Dolby B & C, with various tape 'positions' & record bias. Great item, makes fantastic recordings for the car (see previous mention).

Wonder what the next 'fad' or 'upcycling' trend will be.

Mark

[ricard]

When I was young my family had a Technics tape deck with Dolby (B), but if it was due to bad alignment or whatever, I never liked the result, so I preferred to live with the hiss until I switched to reel-to-reel. Mentally, I still have the image that Dolby 'boxes in' the sound for want of a better expression.

And yes, collectability is in the eye of the beholder, although sometimes people seem to give odd reasons for collecting things, like 'the albums sound better on cassette tape', when it's probably the nostalgia factor that weighs in. On the other hand, ur audio perception is so interwoven with other sensory inputs and our mental state that it probably does make sense to some people.

I enjoy listening to tapes through the built-in speakers of a tape recorder because I'm still fascinated by the 'mechanical/electrical box that makes sounds' concept, even though it certainly does not give the best technical audio quality.

[Mark_RR]

Originally Posted by stevehertz

On the subject of pre recorded cassettes with Dolby, to my knowledge Dolby was never taken up universally. You can find late cassettes that are not Dolby encoded.

I agree, Dolby encoding was never universal.

I started buying music around 1978 and had to go with cassette as I couldn’t afford a record player. At that time, most cassettes had Dolby but it couldn’t be guaranteed. When I got a cassette deck with a Dolby B circuit, I remember always checking carefully to ensure the cassette was Dolby encoded. If it wasn’t, I wouldn’t buy it.

If my understanding is correct, Dolby NR was a licensed technology. Therefore, a fee was payable on any cassette using it. This might account for why some (cheapskate) labels did not use it.

I don’t think I have any of my pre-recorded cassettes from that period now. I never had that many anyway. My brother and I persuaded my Mum to let us have Dad’s old vinyl hifi*, so we switched to buying records quite soon. They were cheaper than pre-recorded cassette and there was much more choice.

(*Connoisseur BD2 TT with Goldring G800, Rogers Ravensbrook and Wharfedale Dentons. The amp and speakers were purchased from Comet in Leeds on 5 Nov 1970 for £70.18.6. These being delivered is one of my earliest memories - I was only 3-1/2 at the time. I still have the amp and speakers.)

The physical quality of pre-recorded cassettes was very variable and the they often didn’t last even when I got a ‘proper’ cassette deck to play them on (JVC KD720B, bought from Lasky’s in Manchester in a sale at £69.90 on 14 Aug 1980). Certainly, my previous Boots portable cassette recorder chewed them quite readily.

Sound quality was also variable. Deep Purple ‘Made In Japan’ sounded amazing though.

With my JVC, my brother and I would record the ‘classic’ sessions that Tommy Vance would play on the Friday Rock show. I used Maxell UD Ferric cassette initially which my Uncle got for me in a Box of 10 from Estuary Audio on the Victoria Station approach in Manchester. I think they were 90p each; that was a lot of money for me then and I was stingy in what I would record to make them last. I still have all those own recorded cassettes. Mostly I used TDK SA pseudo-chrome cassette after the Maxell UDs were used up, so I must have had a bit more money later on.

The JVC was replaced by a Denon DM 34HR in April 1990. I nice quality 3 head deck with adjustable bias and sensitivity. Not in Nakamichi league though. The JVC is long gone, but the Denon is still in my hifi and gets a very occasional use. I also have a ‘back-up’ Aiwa ADS-750, which has Dolby B, C and S.

I do have nostalgia for those home-recording-from-the-radio days, but a lot of the music I recorded then is not what I want to listen to now. That is why my cassettes do not get much playing. My musical tastes shifted to classical and the advent of Minidisc was a game-changer for home recording from Radio 3.

[stevehertz]

The other thing regarding Dolby encoded pre recorded cassettes was the somewhat vague way in which its inclusion was marked on the cassette case or indeed the cassette itself. Usually, there's the double D mark on the spine of the cassette, but not always. Personally, I was never sure one way or the other. Also, to my knowledge, it never stated that it was specifically 'Dolby B'. Ok, it's probably fair enough to assume that Dolby C was never used (was it?) but for sure, the latter was in use when pre recorded tapes were still being produced in 1980. It wouldn't have taken much forethought to print 'Dolby B' printed on the cassette just to make sure that users were confident of using the correct playback system, but they never did. The whole pre- recorded cassette thing was never well done in my opinion; noticeably poor tape quality, poorly recorded, poor information etc etc. But I still collect them, they are what they are, a very important part of vintage hifi and one that - as part of the audio cassette genre - provided a viable, high quality alternative to records and full size tapes.

[jamesperrett]

Originally Posted by stevehertz

The other thing regarding Dolby encoded pre recorded cassettes was the somewhat vague way in which its inclusion was marked on the cassette case or indeed the cassette itself.

I think it depends on the record label. I certainly remember my first Dolby encoded cassettes included a paragraph in the fold out paper liner describing the process and also suggesting that the user turns down the treble if their player doesn't have Dolby noise reduction.

Nowadays one of my pet hates is the wispyness of Dolby B recordings played back without the proper decoding. I can understand why people do this as the reduction in treble with the proper decoding makes the sound instantly duller and less exciting. Any mismatch in levels will also cause the decoder to mistrack so, when I'm transferring a cassette, I will often adjust the level into the Dolby decoder so that cymbal tails sound correct.

[michamoo]

As someone who used cassettes a lot from the late 70s untlil around 2003 i always had the Dolby switch always set to off. To my ears whatever version being used it always resulted in muddy flat sound. Id rather have the hiss and back off the treble a bit. But then i tend to listen to the music and not the delivery system.

[TIMTAPE]

Dolby on cassettes was a mixed blessing. To work as it was designed to it required quite accurate alignment (Dolby tracking) between the cassette being played and the Dolby decoder. The fact that later machines from such as NAD and Yamaha started including a front panel "Play trim" control is telling. It was there to help consumers try and realign the Dolby tracking so that the cassette sounded something like it was intended.

The blurb on Dolby encoded commercial cassettes gave the impression that you could play a Dolby cassette without Dolby decoding so long as you decreased the treble somewhat. Well yes, up to a point, but anyone with reasonable listening skills could hear the Dolby encoder artifacts shhhhing away on all sorts of programme, music, speech, or whatever.

Dolby B was sensitive to everything above say 1000Hz and so often the decoding only worked properly if the cassette also contained that full bandwidth, and the cassette player picked up that full bandwidth right into its decoder, and at the correct levels. All it took to mess up the Dolby tracking was a slightly over or underbiased recording, or a tiny bit of dirt on the record or replay head, or a worn head, or a minute error in azimuth tracking. Just having the machine’s front panel playback EQ switch set for 70 instead of 120 was enough. A combination of these and all bets were off. No wonder most people got frustrated with Dolby on cassettes and usually left the Dolby decoder switched off.

I used to enjoy setting everything up correctly on a decent 3 head cassette machine so you actually got decent Dolby tracking with few Dolby artifacts. Just the music. With care it could sound probably close to a decently recorded and played LP, and without the clicks and pops.

But I share James’ frustrations in trying to accurately decode a Dolby cassette. It can be very tricky and is usually a subjective exercise. In the end you can only use your ears as a guide to how well you’ve got it to track. There is no objective measure that I know of.

An exception is many of the later good pre recorded cassettes by some of the big record companies. At the beginning of side 1 and the end of side 2 is an extremely short series of test tones. Once digitised these can be viewed on a timeline and EQ adjustments made for flattest response. But from there the recording still has to be sent back into the decoder at the proper reference levels. Some of these prerecorded tapes also used high bias or Chrome tapes and were less subject to partial erasure, and had better quality than ordinary Ferric tapes.
But why would you bother? The same commercial recording is probably out on CD or download, with much better sound than you could ever get from a cassette.

People occasionally ask if there is a digital Dolby decoder available today. Some seem tend to think all they have to do is drop a Dolby cassette into a cassette deck, digitise it and then press the digital decoder button and all will come out beautifully. It doesnt work like that. There are so many things that can go wrong, some of them fixable and some not.

Dolby A was used from 1966 but they used professional open reel tape machines , at high tape speeds, with skilled maintenance and alignment, on machines that were designed to be easily and quickly aligned, using line up tones recorded on the tapes (hopefully) etc. So long as the procedures were followed, it was a good system and worked well.

Compare that to a mass consumer system on cassettes designed for convenience where most people couldn’t be bothered with all that careful alignment and maintenance, didn’t understand it anyway, and most cassette machines weren’t set up for those tweaks, and it's easy to see why Dolby on consumer cassette media was a mixed blessing at best.

[stevehertz]

Well, I hear what you're saying but personally I've never had a problem with Dolby B. But then as a musician with a small four track studio, an electronics engineer, and having always owned half decent, well set up and maintained cassette decks, that's probably why. To be frank, I've been in the company of people who couldn't give a damn if the Dolby was switched on or off. Personally I think Dolby B gets a lot of unwarranted bad press from audiophiles. My view is that used properly it is a valuable addition to the audio cassette genre. Not perfect, but an improvement on no noise reduction.

[TIMTAPE]

Yes "used properly" but once we released Dolbyised cassettes to a wider audience, for playing on their own tape machines, we'd lost control of the strict Dolby calibration chain. Our release cassette might have been perfectly calibrated, but unless played on a machine with the same high standards of calibration and Dolby decoding, it was a guessing game as to how it sounded at their end.

Having said that, back in the 90's at my suggestion we started issuing Dolby B encoded cassettes for productions from our state's largest Talking Book Library. But I never expected that those thousands of third generation high speed duplicated cassette copies could be reliably decoded by the cassette players of the print handicapped clients in their homes. Even getting cassette duplicates to Dolby track in-house was unreliable and eventually I gave up trying to reach that level of accuracy - but for a while I did try.

It was years later that I read about Ray Dolby's Dolby C and how he decided to limit the full spectrum encode/decode of Dolby B (right up to 20kHz), down to only 10kHz for Dolby C. He knew how perilously difficult it was to maintain flat response up to 20kHz on cassettes, especially when tapes were played on different machines, and so he wisely gave up on that idea. For 20kHz on standard cassette we're talking seriously short wavelengths. The same wavelength on a studio reel machine at 15ips equates to 320kHz...

These days, if we still have the original Dolby encoded master tapes, we can make (or attempt to make) a decent Dolby decoded transfer to digits and from that moment on, there are no Dolby decoding issues for the consumer to worry about on their (now digital) copy. We've done the hard work for them.