Die Entwicklung der Magnet-Aufnahme aus japanischer Sicht
von Gert Redlich überarbeitet im April 2019 - Durch Zufall habe ich eine sehr ausführliche Zusammenstellung der Geschichte der Entwicklung des Magnetbandtechnik - aus japanischer Sicht - gefunden.
Der Autor Masanori Kimizuka war viele lange Jahre (von 1973 bis 2006) bei SONY, dem zeitweisen Weltmarktführer bei Magnetbandgeräten und natürlich bei der gesamten Unterhaltungselektronik sowie der Profi-Fernsehtechnik.
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Nach dem Lesen der 93 Seiten aus dem Jahr 2012 fand ich viel - uns Deutschen - noch nicht bekanntes Wissen, aber auch erstaunliche Lücken in manchen - aus meiner Sicht - wichtigen zeitgeschichtlichen Ereignissen. Es ist für den Vergleich der jeweiligen - teilweise persönlichen - Sichten sehr interessant, wie ein japanischer Diplomingenieur diese technische Entwicklung detailliert zusammengestellt hatte und dazu chronolgisch aufgearbeitet und zusammengefaßt hat.
Herr Kimizuka war in 2012 der "Director of Japan Audio Society", ein vergleichbarer Ton-Ingenieurs-Verein zu "AES" in USA.
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13.5 Creation of the “Headphone Stereo”*
* "Headphone stereos" refers to a general category of devices perhaps better known by the pet name for the first model: the "Walkman" from SONY. The term is used without distinction (Reihenfolge oder Bewertung) in this report.
The Compact Cassette was rapidly improving in performance and becoming established as the main tape recorder for music. Users were building up collections of recorded music at their disposal.
Music appreciation was becoming more personalised in style and individuals increasingly had exclusive use of their own equipment. The idea of a “headphone stereo” clearly fulfilled people’s aspirations to “listen to music, anytime, anywhere” and would certainly have a decisive effect on the audio environment of the future.
When these devices came out, some people viewed the idea of a tape recorder that could not record as being half-fnished.
However, the Compact Cassette tape recorder had an acceptable level of performance and sound quality and happened to serve the purpose of having “music anytime, anywhere”. A tape recorder becoming the first of these “headphone stereos” was clearly quite by chance, and the concept of portable audio devices continued to change and develop as advances were made in CDs, MDs, semiconductors and media.
The greatest success factor was in the planning of a product that enabled people to “listen to music, anytime, anywhere”. The goal to achieve a portable device came down to the matter of making a simple machine that was small, lightweight and low in energy consumption.
As there was a pre-defined tape size and mechanism for the Compact Cassette, various mechanical innovations and clever circuitry had to be incorporated into the tape “headphone stereo”, but developers finally managed to achieve the ultimate in downsizing.
Zum ersten Mal wird in dieser Arbeit Akio Morita, the chairman of Sony Corporation, referenziert :
In 1989, at the time, wrote a thought-provoking passage in a commemorative publication celebrating the Walkman’s tenth anniversary, outlining what sparked the creation of the Walkman, the planning behind it, the naming of it and other matters. The passage is reproduced below for reference.
Reprinted from “Walkman Ten-Year Anniversary Publication”
Reprinted from “Walkman Ten-Year Anniversary Publication”, Sony Public Relations Offce, ed. (1989)
"The Walkman" - a Success in Product Planning
(geschrieben von :) Akio Morita, Chairman of Sony Corporation (at the time):
Was it 1978? One day, Mr. Ibuka came into my office carrying a remodelled cassette player and a pair of headphones and said, “I wonder if you could listen to a stereo while you’re walking.” At the time, stereos and headphones were too big and heavy to listen to while walking. But when I listened to the sound on Mr. Ibuka’s remodelled player, there was defnitely something better about it than listening to music through a speaker. You could also listen to it by yourself.
I thought, “Well, this is quite fun!” After that, I started thinking about where people listened to music. Young people had stereos in their rooms, cars had car stereos - but you couldn’t listen to music while walking down the street. I thought of how I had seen people from time to time walking along carrying a radio cassette player with them.
“Young people want to listen to music all the time,” I thought. I started thinking with more interest about the cassette player Mr. Ibuka had brought in to me.
Mr. Ibuka had also suggested remodelling the popular “Pressman” cassette recorder and taking out the recording unit and speaker. I asked everybody, “Wouldn’t it be more fun if we could make a stereo much lighter?” Most of them said, “That would never sell.”
Keiner wollte mitmachen - und dann noch ein häßlicher Name
There was no support from anyone in our acoustics division either. This was because “we had never sold a tape recorder that could not record”. But when I thought about it, we sold a lot of car stereos and they could not record. So I thought, “All you need when you’re walking is a player. Let’s defnitely make one.”
I got serious and gave the order to build a prototype. Super-express development got under way, with the strict aim of launching it on 1 July 1979.
During that time, I was thinking, “We have to come up with a good name for it.” One day, when I came back from a business trip, Mr. Kuroki, who was head of the Product Planning Center at the time, told me, “We’ve decided on the name ‘Walkman’.” “Walkman? That’s an odd name. Aren’t there any better names than that?” I asked.
“Sorry, it’s too late. All the packaging and posters say Walkman, so we can’t change it. Please, will you accept it?” was his reply. “In that case, we can’t do anything about it,” I said.
It went on sale on 1 July 1979 under the name of “Walkman” (TPS-L2). Of course, at the time, we had no idea it would become such a big business. I did, however, have some confidence and thought to myself, “We can do this.”
Für jedes Land einen eigenen Namen ?? Unsinn ....
This was because I knew that young people could not do without their music. Another reason was my own home situation: my children were always pounding the stereo, but if they had this kind of device, I could have some quiet in the house! When we tried to market it overseas and took it to SONAM (Sony Corporation of America), they said, “‘Walkman’ is weird – it’s not English. We’re not going to use that name.”
The name SONAM came up with was “Soundabout”. I thought, “That’s a strange name, but we’re selling it in English-speaking countries, so let’s go with what the people in those countries say,” and decided to market it with that name in the United States.
But then Sony UK said, “‘Soundabout’ is no good!” The English have a certain pride in being the originators of their language and they were not satisfied. So in England, the product was marketed as the “Stowaway”. I didn’t really know what this meant, either, but when in Rome, do as the Romans do.
Nein, "er" heißt jetzt “Walkman” - und fertig !
However, the Walkman got very popular in Japan and visitors from other countries would buy them to take home as keepsakes. As this happened, the name “Walkman” started becoming known overseas.
The name was easily understood by non-English-speaking people and use of the name started spreading throughout the world. So I decided, “If that’s the case, let’s just call it ‘Walkman’ everywhere in the world.” I gave the presidential order (I don’t really like that word) to change the name to “Walkman” in the United Kingdom and the United States as well, uniting the “Walkman” across the world.
The Walkman soon became a global hit and we put out new models one after another. The appearance of the Walkman changed the way people listened to music, which had a major impact on the world.
I know that when other companies later put out their own stereos with headphones, everyone called them Walkmans as well.
When I was awarded the "Albert Medal" by the United Kingdom Royal Society of Arts in 1982, I said in my speech that “although Sony has created various new products, we are actually not limited to manufacturing products. We also innovate with words and have made ‘Walkman’ into an English word.”
I was given a standing ovation! But what made me happiest of all was when “Walkman” appeared in the Oxford English Dictionary, the most authoritative English dictionary in the world.
This means that “Walkman” has been recognised as an English word. In the past ten years, we have given the world 50 million Walkmans, a new word and a way to listen to music that they didn’t have before. I think we can be very proud of that.
The brilliance of the Walkman is in its product planning. Cassette players and headphones already existed. However, what made the Walkman such a hit was the immense creativity in the product planning. While new inventions and discoveries are important, the Walkman has proved that if we have the sense to come up with a completely new product using existing technology, it can develop into an entire industry of its own.
13.6 Advances in the Walkman
The first “headphone stereo” that appeared under the name of “Walkman” was a handheld TCM-100 recorder remodelled into a playback machine.
While opinions were divided as to whether it would sell or not, product developers adopted a design that took full advantage of existing products to reduce the risk.
Since the same casing was used, the design was almost exactly the same in outward appearance as existing models, except for the blue exterior, which drew attention to the device’s new image.
The accompanying headphones were a new, small, lightweight type that had been developed and commercialised at the same time. Marketed this way, there was overwhelming support for the product and it became wildly popular in no time.
With the huge success of the TPS-L2, planning immediately started on new dedicated-playback models, aimed at coming up with an original design that would fully embody the “headphone stereo” concept.
When the Walkman came out in 1979, the market for standalone, small-scale tape recorders was smaller than the radio cassette player market; there had been no investment in the development of dedicated personal devices, so existing devices had to be used for design miniaturisation and design support.
In 1981, the second “Walkman” WM-2 (Fig. 13.3) was launched. This monumental model was the first to be designed exclusively as a Walkman, expressly embodying the “headphone stereo” concept and showing the way of the future.
Competition then ensued between many other manufacturers as well as Sony to develop a product that was “smaller, lighter and played for longer”. The “headphone stereo” fundamentally changed the way people listened to music.
13.7 The challenge of miniaturisation
Once headphone stereos had gained popularity, fierce competition ensued to further enhance what were the portable device's most appealing features: small size and light weight. Since the tape size was already predetermined, the devices could not be made any smaller than this.
However, one goal was to make a device that was the same size as the case that the tape was put into, but this size was absolutely impossible to achieve using existing tape recorder designs. The greatest obstacle to making a tape player the same size as a tape case was the size of the motor and the battery.
Sony’s challenge was to make full use of the characteristic properties of a dedicated playback machine to make the ultimate small-sized machine. Compact Cassettes had a difference in thickness between the area into which the heads were inserted and the area where the tape was wound. This difference was around 1.5mm on each side.
The first idea was to put the motor into this area, so an ultra-thin, dedicated brushless motor was developed. The standard design had two AA batteries; however, the developers made a detailed study of the magnetic circuit in the motor and other areas and perfected a design that could operate on one AA battery.
Of course, this required a new amplifer design that could run on 1.5V. Even though there was only one AA battery, it was no simple task as to where to put it. This is where the design capitalised on the characteristic properties of a dedicated playback machine: the solution was to store the battery where the erase head would have gone (Fig. 13.5). While this design achieved the ultimate in downsizing, it meant the unit where the head was mounted, including the battery compartment, had to be pulled out in order to load a tape and some people would have inevitably thought of the device as a bit of a gimmick.
However, the cassette-case-sized Walkman WM-20 (Fig. 13.4) was launched in 1983, and made a huge impact with its size. It was truly an epoch-making point in Walkman miniaturisation history.
Exakt so groß wie die CC-Kassette . . . .
The ultimate miniaturisation challenge was to make the perfect cassette-case-sized machine, even though it was not actually possible to make a machine the exact same size as a cassette case, as the mechanism protruded a little when in use.
The AA battery was a constant hurdle to downsizing, so developers worked on a new, thin, rechargeable “gumstick battery”. They also worked on other developments to downsize individual components, such as developing new, special-shaped heads that were smaller in size. The expansion of the “headphone stereo” market and the significant development investment that was being put in meant that it was economically worthwhile to work on these components.
This created a virtuous cycle in which developers actively worked on new components, which in turn increased the appeal of the overall product. The WM-101 (Fig. 13.6) was released in 1985.
Loaded with these new components, it truly was the size of a cassette case, marking the end of the size competition (Figs. 13.7, 13.8).
Progress continued on the Walkman in various ways, such as improved function and performance, increased variation in models and more advanced designs. For a long time, it remained the favourite choice of portable audio device, while the cassette deck remained the machine of choice for recording on Compact Cassettes.
Basic performance improvements continued on the cassette deck and new technology standards were set and standardised for it, meaning that it now could record to a very high level of quality despite the strict specifcations in place. Developers had made good use of the characteristic nature of dedicated playback machines and focused their efforts on making the “headphone stereo” smaller, which added to its product appeal. Of course, the success of the “headphone stereo” was undeniably the very concept itself, which fundamentally changed the way people listened to music.
13.8 Production Innovation
Since the creation of the Walkman, many of the costs involved making it smaller and more energy efficient as well as improving its sound quality and other functions and performance.
This work and its strong product appeal meant that it had remained relatively highly-priced. While the high-performance, small-scale, sleekly-designed models were well received in Japan, the structure of the overseas market meant that cheaper machines would sell better, even though they were slightly bigger and had fewer features.
Accordingly, lower-priced machines, produced by latecomer manufacturers, continued to occupy a large share of the market. Around the mid-1980s, Sony decided to work on a product that was competitively low-priced and launched its “P-Project”, aiming to create a Walkman after the manner of disposable cameras (also called “throwaway cameras”), which sold for ¥980.
In an all-out cost-cutting move, the company discarded its existing system of assembling mechanisms and electronic circuit units separately and then putting them together. Instead, it devised a system of directly incorporating the mechanism unit onto a printed circuit board and dispensing with the mechanism chassis.
This system was a success. Other success factors were the use of a lot of plastic parts and the fact that this system used around half the usual number of parts. The company also achieved a more streamlined assembly process, with a one-way automated assembly design that involved four mechanisms being made on one printed circuit board and then separated afterwards to create
the final product.
This approximately halved the usual cost, thereby boosting the line-up of low-priced products aimed at the global market with these domestically-produced products.
14 Invention of Digital Audio Tape Recorders (DAT)
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14.1 Dawn of Digital Audio (die Morgendämmerung)
Major technological developments took place on the Compact Cassette throughout the 1970s and 1980s and it finally reached a point of completion as a magnetic recording system that performed adequately for consumer use.
The appearance of the Walkman in 1979 rapidly boosted the usefulness of the Compact Cassette, making it a vital part of the establishment and development of a new genre of audio products: portable audio.
At the same time, tangible results were being seen in the development of practical applications for digital audio and it was considered a matter of course that Compact Cassette systems would also progress to being digital.
The digitalisation of audio started with the development of magnetic tape recording systems and the end result was the DAT (R-DAT for consumer use). The development history of the DAT is very important to digital audio.
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Es begann in den späten 1960ern
Research on the use of digital technology in recording and playing back audio signals began in the late 1960s, under Heitaro Nakajima at the NHK Technical Research Laboratories.
This was around the same time as talk of FM broadcasts coming to the end of the experimental stage and starting in earnest. FM broadcasts were stereo capable, had acceptable sound quality and were very appealing to amateur music enthusiasts and audiophiles.
However, there was still room for improvement, as the sound quality was not quite perfect. The question of how to improve the sound quality of FM broadcasts triggered the development of digital audio in Japan.
Researchers started out first by reviewing the current situation: completely reconsidering and reassessing every element that went into FM broadcasting, from programmes to transmitters and receivers. The transmission itself as well as the master tape recorders used in the various parts of production, such as compiling and editing sound, clearly affected the overall performance.
It was clear that improving the performance of these master tape recorders was of utmost importance to improve the quality of FM broadcasts. Fig. 14.1 shows the dynamic ranges at each stage from recording to transmitting.
Magnetic recorders, enclosed by a dotted line, had the smallest dynamic range and therefore limited the overall performance of the entire system. Despite the fact that the master tape recorders of the day all used analogue recording, they were high-performance business machines and many of them were highly praised for their sound quality, even by famous recording studios.
While various attempts were made to improve the performance of these master tape recorders by improving the key components, such as the heads, or the hardware, such as the driving system, or varying the optimum recording levels, this achieved little in the way of improvements, which meant that nothing signifcant could really be expected to be achieved.
Das waren also die bis hierher aufgezeigten Grenzen
Having clarified the limitations of the existing analogue machines, it was necessary to somehow come up with a completely different solution. A proposal was made in the laboratory to try applying digital technology to audio.
At the time (mid 1960), digital technology was being used in computers and communication technology. When researchers applied it to audio recording, they could see how it was theoretically possible for the expected performance to far outperform that of the existing analogue machines.
However, while the idea of digital audio recording – storing the waveform of a signal as a numerical value – was relatively simple, implementing it in an actual machine was no simple matter.
A vast amount of data had to be recorded in a far greater volume than for analogue recording; this had to be recorded and played back at very high speeds. The existing analogue tape recorders could not cope with such demands.
Nur der Videorecorder war geeignet
To solve this issue, an idea was put forward to use a video tape recorder (VTR), which was being developed for business use at the time.
VTRs were designed for recording video signals; they used rotary head technology to record a greater volume of signals at a higher speed than that of an audio tape recorder.
The frst audio prototype was completed in 1967, incorporating an A/D - D/A converter and a signal processing circuit into the VTR mechanism (Fig. 14.2).
While the prototype was mono, the properties of the sound were sufficient to show the great potential of digital audio. The development team concentrated on further improvements to put it to practical use, completing a second prototype that was capable of stereo.
In 1969 konnte er auch Stereo
In May 1969, a general-audience playback demonstration was held at a public event hosted by the NHK Technical Research Institute (now NHK Science & Technical Research Laboratories).
The fresh sound and lack of noise stunned many industry stakeholders and general listeners in the audience. Incidentally, the demo music was an overture from the Rimsky-Korsakov opera "The Golden Cockerel", performed by the NHK Symphony Orchestra, a fitting song choice to usher in the beginning of the digital audio era.
Es fehlte etwas ganz Wichtiges - das Cutten
The demonstration of digital audio to the public was a huge success, but there was no means of editing the sound. The devices were still in their early stage and would be diffcult to downsize; they also had their own digital countermeasures for noise (largely because of inadequate error correction).
The machines were not yet perfected enough to be of any practical use as master tape recorders for broadcasting. The NHK put the development of digital audio recorders on hold for the time being, perhaps because it had deemed that it would take vast resources to address the issues in question.
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Erste PCM Aufnahmen auf einer Quadruplex Maschine
However, Nippon Columbia, which had worked on improving the sound quality of records by direct cutting, had a technical interest in digital audio and its potential. It took over the research and development of the technology and was able to create a master tape recorder with it.
The machine used a so-called "four-head VTR", with two-inch tape, as its recorder, complete with a 47.25kHz sampling frequency and 13-bit linear quantization. LP records that were mastered and produced on this digital master tape recorder went on sale in 1972 under the name of “PCM Records” (Fig. 14.3). The superior sound quality was highly regarded and became all the rage among audio enthusiasts.
14.2 Competition over the Development of Stationary-Head Machines for Business Use
Digital audio was unveiled (presented) for the first time in a public demonstration in 1969, taking major electrical manufacturers by surprise at its tremendous potential.
Inspired by the development of the digital audio tape recorder (DAT), major electrical manufacturers hastened their development of (analog) master tape recorders for business use in the early 1970s.
Production technology at recording studios and other music production sites became more sophisticated, with (analog) multi-track recording and more complex mixing processes. In turn, this required higher levels of sound quality with a greater dynamic range and higher S/N ratio than the existing analogue equipment.
The audio genre began to make rapid progress as an industry; advanced recording and playback equipment became essential to audio device manufacturers for assessing and analysing their machines. Given these demands, fierce competition ensued to develop a DAT for business use.
Die BBC hatte 1972 einen PCM Recorder mit feststehenden Köpfen
Several fairly-perfected systems were proposed right at the end of the 1970s (Table 14.1). Most of the systems proposed at this time were “stationary-head” machines, with open reel tape drive systems and heads with multiple recording tracks on them. These were very similar in appearance to the existing analogue master tape recorders.
Although a number of major Japanese manufacturers, such as Sony, Mitsubishi, Hitachi and Matsushita, worked on developing this technology together with NHK, it was the BBC in the United Kingdom that developed and test-built a digital recorder with a stationary head like the ordinary analogue machines around 1972 (Fig. 14.4).
The technology was taken over by US company 3M, which used it in a 32-channel machine using one-inch tape and a four-channel machine using half-inch tape. Production of these machines stopped after several years, due to their high price and propensity to break down.
Konkurrenz kam auf, mit VTR Konzepten
In 1977, US company "Soundstream" remodelled the tape recorder, developing and announcing a four-channel DAT, but this, too, failed to gain a commercial footing and disappeared within a few years.
While DATs started out using VTR rotary head mechanisms, many stationary-head systems were developed because they were thought to be more beneficial for multi-track recording and editing.
Both manufacturers and producers were rather conservative and felt uneasy with the rotary head mechanisms that had been developed for VTR and their ease of use; they already had certain underlying assumptions of what tape recorders should be like.
Alle diese Entwicklungen kamen aus Japan
Table 14.1 shows the stationary-head digital tape recorder systems for business use announced by each company. Compatibility required at least a minimum level of collaboration; accordingly, discussions were held at AES to define the Digital Audio Stationary Head (DASH) format in 1983.
In 1985, the Professional Digital (PD) format was also proposed as a rival to DASH. Before long, ferce competition spread throughout the world of digital master tape recorders. Both systems had been independently developed by Japanese manufacturers, and it is no overstatement to say that the technology was completely Japanese and that Japan was leading the world in digital tape recorders for business use (Fig. 14.6).
This accumulated technology and success with new audio equipment, such as the “headphone stereo”, the radio cassette player and the small-scale stereo, were major factors behind Japanese manufacturers leading the world in developing DATs for consumer use.