Cassette - 50th anniversary

RobHolt

RobHolt

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Yes, 2012 marks the 50th anniversary of Philips introducing the first ever cassette tape recorder, the 3300.

Originally introduced for dictation purposes it was soon adopted by kids making music compilations and pirating stuff from records and radio.
Of course it later went on to feature in most hi-fi systems during the 70s and 80s helped in no small part by Dolby B & later C noise reduction.

The technology peaked in the early-mid 1980 with the likes of Nakamichi, JVC and Pioneer introducing decks capable of making recording very close to the source.

I remember my first recorder given as a present by my parents in the early 70s, a small Ferguson unit complete with microphone. Not being satisfied with the sound, off we trotted to the local TV and hi-fi repair shop to buy a small loudspeaker to make it sound better. That gave it a much nicer 'tone'.

It got most use on Sunday nights with the mic plonked in front of the radio to record Tom Brown's Top of The Pops. Pretty horrible recordings but everyone starts somewhere :)

Good to see cassette still around, and that it made the big 50.

1stecassetteplayer.jpg


Philips 1st machine, the 3300
 
Does it count as an anniversary, since all production has stopped?

I remember you doing an A/B demo of your JVC vs. CD and I couldn't hear much difference at all! Impressive for such a thin bit of tape :)
 
They still make tape and recorders:

http://www.dv247.com/studio-equipment/tascam-202mkv-professional-dual-well-cassette-deck--64232

http://uk.maxell.eu/en/categories/cassettes-25.aspx

Alive but not exactly kicking :)

I remember the excitement when 'Metal' tape became available which could accept much higher recording levels, especially at HF where tape had traditionally been weak.
Took a while for deck manufacturers to catch up since many early machines couldn't actually achieve the higher levels without the head saturating or the replay electronics clipping. Got there in the end though in most cases.

Cassette was my favourite source for a while becasue i just loved the machines and the tech that went into them.
 
I had a Nakamichi 482Z in the '80s, and when properly aligned, it could make recordings indistinguishable from the original provided the recoring level was kept to 0dB or below, and with Dolby C to reduce the noise.

The problem with all tape was the critical alignment, that required test equipment and patience. In the studios, we would align the tape machines every day, for azimuth, bias and EQ. I would realign my Nak likewise every time I did a recording, and the results were pretty damn good, but oh so tedious. I wasn't sad to go over to PC recording!

S.
 
Nackamichi were undoubtedly at the top of the game.

TEAC always made good reliable machines too, and I always had a soft spot for JVC's finest machines from the early 80s.

I have a nice JVC DD9 here now.
Three head, dual captan, three motors with Quartz lock direct drive - very unusual for a cassette deck.
It has an auto calibration function so that for any tape inserted it will record a series of test tones via the record head, 'listen' to them back via the replay head and then adjust the internal circuits for bias, equalisation and sensitivity.
The level of complexity required in the circuits back in the 80s to enable this is a marvel to see.
The DD9 still works perfectly, likely because of the DD as there are no belts to wear.
 
Interestingly, I remember seeing some measurement fors Nakamichi Dragon, vs. Sony Pro Walkman. The Pro Walkman came out better in most cases :) I sold mine to David Price, lol. Still not as good as the JVC though I think Rob. Probably because of the auto-alignment. I have no idea what tapes the Pro Walkman was made to use.
 
All tapes need a specific bias for the best performance balance.
Increasing bias allows you to record more LF & MF on to tape but reduces the point at which the tape saturates at HF.

Frequency response also changes as bias is adjusted.

Sensitivity also varies between tape brands and this became important with the introduction of companding noise reduction systems like Dolby and DBX. With those systems, the expand element of the process only works property if the signal entering the NR circuit (via the tape) is the same nominal amplitude (usually referenced to 300Hz IIRC) as during the recording because the two elements of the system should be a mirror image.

The problem with fixed decks is that bias and sensitivity was factory preset for certain types of tape. Often this wasn't hugely accurate and the more adventurous could open the case and tweak the little posts on the pcb. Some machines introduced user variable bias which helped but it didn't address the sensitivity issue.

One interesting development was Dolby HX and HX Pro.
It was noticed that when the tape head and tape were being driven hard, this effectively increased the tape biasing effect and reduced HF headroom and response. HX would reduce bias on the fly, dynamically tracking the signal and improving performance.

Dolby B limited processing to 10dB, and the later C version doubled this to 20dB. DBX was more aggressive and would give up to 30dB but this additional noise reduction came at a price. The old analogue technology as used in the domestic processors could be heard modulating the noise floor, so for example listening critically to solo piano would often reveal a swishing sound as the noise floor bobbed around. The effect was pretty much inaudible with Dolby B, occasionally audible on critical program with C, and pot luck with DBX :)
You could get away with iffy alignment on B, but C & DBX sound pretty compromised if everything isn't spot-on due to the degree of signal manipulation.

Can you tell I did a paper on this for a school science project - LOL
 
I had a Walkman Pro for years. It was they only tape machine I ever owned - apart from one that came with a "Ghetto Blaster" and a couple of cars that had slots to stuff cassettes into.
 
RobHolt said:
All tapes need a specific bias for the best performance balance.
Increasing bias allows you to record more LF & MF on to tape but reduces the point at which the tape saturates at HF.

Frequency response also changes as bias is adjusted.

Sensitivity also varies between tape brands and this became important with the introduction of companding noise reduction systems like Dolby and DBX. With those systems, the expand element of the process only works property if the signal entering the NR circuit (via the tape) is the same nominal amplitude (usually referenced to 300Hz IIRC) as during the recording because the two elements of the system should be a mirror image.

The problem with fixed decks is that bias and sensitivity was factory preset for certain types of tape. Often this wasn't hugely accurate and the more adventurous could open the case and tweak the little posts on the pcb. Some machines introduced user variable bias which helped but it didn't address the sensitivity issue.

One interesting development was Dolby HX and HX Pro.
It was noticed that when the tape head and tape were being driven hard, this effectively increased the tape biasing effect and reduced HF headroom and response. HX would reduce bias on the fly, dynamically tracking the signal and improving performance.

Dolby B limited processing to 10dB, and the later C version doubled this to 20dB. DBX was more aggressive and would give up to 30dB but this additional noise reduction came at a price. The old analogue technology as used in the domestic processors could be heard modulating the noise floor, so for example listening critically to solo piano would often reveal a swishing sound as the noise floor bobbed around. The effect was pretty much inaudible with Dolby B, occasionally audible on critical program with C, and pot luck with DBX :)
You could get away with iffy alignment on B, but C & DBX sound pretty compromised if everything isn't spot-on due to the degree of signal manipulation.

Can you tell I did a paper on this for a school science project - LOL
Click to expand...

Interesting that the first implementation of Dolby C used two Dolby B processors in series. This was later done in a single IC, but the tracking was slightly (but audibly) different such that a Dolby C tape recorded on a single processor machine wouldn't decode accurately on a dual processor machine, and vice-versa.

I concur fully that Dolby C required the tape machine to be aligned very accurately, to within 1dB for sensitivity, with record and playback EQ also needing to be pretty accurate.

One constant irritant for me was that I would line up my machine for one particular tape, then next time I bought a batch found that the manufacturer had "improved" the tape, usually increasing the HF sensitivity so that it would sound brighter on demos, but that screwed up my alignment, and I'd have to do it all over again. There was even sufficient variability between batches even if there hadn't been any "improvement" that every recording I did required at least checking the line-up if not some adjustment. Professionally, the studio I first worked at, we would line up the machines every morning, and always used the same tape (Scotch 206 as I recall) which was bought in very large batches and random checked for consistency box to box.

I was both amused and irritated by those who said that Dolby ruined the sound, or that they recorded with Dolby and played back without. Nothing wrong with Dolby, it was their machines being out of alignment.

S.
 
Still rocking the cassette via a Yamaha KX-580 and a Teac as back-up. Mainly to transfer to digital, mind, got a couple of hundred tapes still to copy. Think I've even got a bit of Tom Brown doing the "Top 20" (Radio 2, just before the shipping forecast) somewhere...

Pete
 
Had many years great service from my Goodmans SCD100 (Nakamichi 500)

A wonderfully versatile machine. :)
 

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