[Vintage-Audio] Re Birth Of The Compact Disc

[Duane Fischer, W8DBF]

Pink Floyd: Want to buy my Laser Disc copy Michael? See the music, hear the 
music, feel the music! If you need a LD player, I have a new one of them 
too, the Pioneer DVL-919. It plays a music CD, LD movie or DVD. Stereo for 
the CD and all sorts of enhanced Dolby, surround 5.1 and more.

The skipping you spoke of was due to a lack of "oversampling". The player 
needed to read the same code multiple times, a delay then caused all 
readings of the same data to be condensed into one. This oversampling 
eliminated the issues you spoke of. The better CD players had more 
oversampling, such as 6 times oversampling or ten times oversampling etc.

The audio on the Laser Disc movies, or music videos, as in a concert not a 
song, blows DVD audio away! Come on over and bend an ear here Michael and 
you can see, hear and feel the difference between LD and DVD.

Duane Fischer, W8DBF/WPE8CXO
dfischer at usol.com
HHI: Halligan's Hallicrafters International
http://www.w9wze.net
HHRP: Historic Halligan Radio Project
hhrp.w9wze.net

----- Original Message ----- 
From: "michael salmons" <salmonsm at missouri.edu>
To: "Vintage home and professional audio equipment from 1975 back" 
<vintage-audio at mailman.qth.net>
Sent: Sunday, December 16, 2007 9:52 PM
Subject: Re: [Vintage-Audio] Re Birth Of The Compact Disc


>I didn't leap on board instantly, but I was intrigued by the promise  of 
>CDs and finally made the plunge around '85 when prices were  starting to go 
>down. I bought one of the all-metal portable Sony  Discmen and a Carver 
>Digital Time Lens home player. The Discman was  crappy. Build quality was 
>great but as the anti-skip technology was  very new, just carrying it 
>around resulted in bad skipping. It would  do fairly well when stationary 
>but still skipped for no good reason  every once in a while. I do remember 
>the available titles had  increased but tstill was not great at that time. 
>I don' t remember  how much I paid but it was not cheap. i do remember the 
>carver set my  back five bills plus tax. It was also built like a tank and 
>fortunately sported error-free performance. The sound quality was 
>significantly better than the discman- I believe they had some kind  of 
>circuit that emulated tube sound. I loved it and it alone  functioned as my 
>stereo (with a pair of good headphones) for a couple  of years at least. I 
>kinda wish I still had one- I sold it to a guy  when I needed to move and 
>couldn't afford to. Sad but true.
>
>  My first discs were Pink Floyd- Dark Side of the Moon and the  Beatles- 
> Abbey Road.  The sound was really pretty good. It was  amazing enough just 
> to hear Dark Side of the Moon with no clicks and  pops. Of course nowadays 
> I listen to my pristine 30th anniversary 180  gram edition on a NAD 
> turntable with an RG noise reducer/dynamic  processor, and over my Boston 
> A-150s it sounds better than it ever  has on any CD I've heard. I'm a 
> little biased toward vinyl though!
>
> On Dec 16, 2007, at 7:51 PM, Gerry Steffens wrote:
>
>> On October 1, 1982 Sony introduced the CDP-101, the first compact  disc 
>> audio
>> CD player on the market at a retail price of about $900.
>>
>>
>> The first CD:
>>
>> In the spring of 1981, Herbert von Karajan, conductor of the Berlin
>> Philharmonic orchestra, was one of the first outsiders to be  allowed to
>> listen to the CD at Philips.
>>
>> He instantly fell in love with the quality of the new medium. In  April 
>> of
>> that year, during the Salzburger Festspiele, Von Karajan decided to  play 
>> the
>> new sound at a press conference. "This is a technological advance  that 
>> is
>> comparable with the changeover from gas lamps to electric light,"  he 
>> told
>> his audience.
>>
>> Von Karajan’s enthusiasm was however not sufficient to win over the 
>> record
>> companies for the new medium. PolyGram, a Philips subsidiary, only 
>> changed
>> its track when Jan Timmer (later president of Philips) took over  the 
>> helm.
>> He announced a 500-day program to develop CD presses and to take  the 
>> market
>> by storm one and a half years later with half a million CDs.
>>
>> Very precise equipment is required for the production of a CD. It  starts
>> with the production of one CD, the master. A powerful laser writes the
>> information on a light-sensitive layer. The parts exposed to laser  light 
>> are
>> etched away, thus giving rise to the pit pattern. This positive  master 
>> is
>> used to make a negative die from nickel. This ‘stamper’ has bumps  at the
>> places where pits are to be made in the CD.
>>
>> When the stamper is ready, it is installed in the core of the CD  press. 
>> The
>> negative die forms a part of the mould which is used to cast the  CD. The 
>> CD
>> is cast by heating plastic (polycarbonate) and injecting it into  the 
>> mould.
>> When the plastic has cooled, it leaves a disc in the mould which has a
>> precise imprint of the pit pattern. This disc then passes to the 
>> following
>> station in the machine to be given a reflective aluminium layer on  the 
>> side
>> with the pit pattern. This layer causes the laser light to be  reflected 
>> when
>> the CD is played. In the following process step the aluminium layer is
>> coated in a protective transparent lacquer. The lacquer prevents the
>> aluminium from oxidising and ensures that the CD remains  antistatic. In 
>> most
>> cases a label is then printed on the CD in the same machine.
>>
>> All of this must be carried out with great precision. A single  particle 
>> of
>> dust can potentially cause irregularities and subsequently lead to 
>> hitches
>> in the music. In the early days expensive cleanrooms were required  to 
>> allow
>> the equipment to operate unhindered and, because every person  carries a 
>> lot
>> of dust with them, the specialist technologists were dressed like 
>> astronauts
>> so as to prevent any risk of contamination.
>>
>> The extremely short development time for a CD factory could only be 
>> achieved
>> using concurrent engineering, at that time a new way of carrying out
>> large-scale production. Various technical aspects of the presses  were 
>> not
>> developed one after the other, but in parallel by separate teams.  This 
>> meant
>> that work was being carried out simultaneously on the processes for  the
>> presses, the application of a reflective metallic layer, the  protective
>> transparent coating, the printing of a label and the design of a 
>> factory.
>>
>> This parallel method of working requires that the development teams  are
>> exceptionally well geared to one another. The manner in which the 
>> reflective
>> layer had to be applied, for example, was very much dependent on the
>> temperature during pressing or on the properties of the protective 
>> coating.
>> A change in one process had consequences for another.
>>
>> The PolyGram engineers did not know whether or not the result would be
>> favourable until just before they were to commence building the  factory.
>> Then a prototype CD player became available with an audio output,  with 
>> which
>> the music could be made audible. Until that point in time, the test
>> pressings could only be assessed by means of measuring instruments.
>>
>> In August 1982 the real pressing was ready to begin in the new  factory, 
>> not
>> far from the place where Emil Berliner had produced his first  gramophone
>> record 93 years earlier. (Deutsche Grammophon, Berliner’s company,  had 
>> by
>> now become a part of PolyGram). The first CD that was pressed in  Hanover 
>> was
>> a recording of Herbert von Karajan conducting the Alpine Symphony  by 
>> Richard
>> Strauß. In January 1983, 500 working days after the start of  production,
>> half a million CDs had been made. The demand from Japan in  particular 
>> was
>> overwhelming. In North America a handful of titles were released in 
>> 1982,
>> one of the first was Billy Joel's 52nd street.
>>
>>
>>
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>> ** For Assistance: dfischer at usol.com **
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