audio tape

Reel-to-reel, cassette and cartridge audio tape formats restored and digitised in the Greatbear studio

Sep

2013

Measuring signals – challenges for the digitisation of sound and video

In a 2012 report entitled ‘Preserving Sound and Moving Pictures’ for the Digital Preservation Coalition’s Technology Watch Report series, Richard Wright outlines the unique challenges involved in digitising audio and audiovisual material. ‘Preserving the quality of the digitized signal’ across a range of migration processes that can negotiate ‘cycles of lossy encoding, decoding and reformatting is one major digital preservation challenge for audiovisual files’ (1).

Wright highlights a key issue: understanding how data changes as it is played back, or moved from location to location, is important for thinking about digitisation as a long term project. When data is encoded, decoded or reformatted it alters shape, therefore potentially leading to a compromise in quality. This is a technical way of describing how elements of a data object are added to, taken away or otherwise transformed when they are played back across a range of systems and software that are different from the original data object.

To think about this in terms which will be familiar to people today, imagine converting an uncompressed WAV into an MP3 file. You then burn your MP3s onto a CD as a WAV file so it will play back on your friend’s CD player. The WAV file you started off with is not the same as the WAV file you end up with – its been squished and squashed, and in terms of data storage, is far smaller. While smaller file size may be a bonus, the loss of quality isn’t. But this is what happens when files are encoded, decoded and reformatted.

Subjecting data to multiple layers of encoding and decoding does not only apply to digital data. Take Betacam video for instance, a component analogue video format introduced by SONY in 1982. If your video was played back using composite output, the circuity within the Betacam video machine would have needed to encode it. The difference may have looked subtle, and you may not have even noticed any change, but the structure of the signal would be altered in a ‘lossy’ way and can not be recovered to it’s original form. The encoding of a component signal, which is split into two or more channels, to a composite signal, which essentially squashes the channels together, is comparable to the lossy compression applied to digital formats such as mp3 audio, mpeg2 video, etc.

A central part of the work we do at Greatbear is to understand the changes that may have occurred to the signal over time, and try to minimise further losses in the digitisation process. We use a range of specialist equipment so we can carefully measure the quality of the analogue signal, including external time based correctors and wave form monitors. We also make educated decisions about which machine to play back tapes in line with what we expect the original recording was made on.

If we take for granted that any kind of data file, whether analogue or digital, will have been altered in its lifetime in some way, either through changes to the signal, file structure or because of poor storage, an important question arises from an archival point of view. What do we do with the quality of the data customers send us to digitise? If the signal of a video tape is fuzzy, should we try to stabilise the image? If there is hiss and other forms of noise on tape, should we reduce it? Should we apply the same conservation values to audio and film as we do to historic buildings, such as ruins, or great works of art? Should we practice minimal intervention, use appropriate materials and methods that aim to be reversible, while ensuring that full documentation of all work undertaken is made, creating a trail of endless metadata as we go along?

Do we need to preserve the ways magnetic tape, optical media and digital files degrade and deteriorate over time, or are the rules different for media objects that store information which is not necessarily exclusive to them (the same recording can be played back on a vinyl record, a cassette tape, a CD player, an 8 track cartridge or a MP3 file, for example)? Or should we ensure that we can hear and see clearly, and risk altering the original recording so we can watch a digitised VHS on a flat screen HD television, in line with our current expectations of media quality?

Richard Wright suggests it is the data, rather than operating facility, which is the important thing about the digital preservation of audio and audiovisual media.

‘These patterns (for film) and signals (for video and audio) are more like data than like artefacts. The preservation requirement is not to keep the original recording media, but to keep the data, the information, recovered from that media’ (3).

Yet it is not always easy to understand what parts of the data should be discarded, and which parts should kept. Audiovisual and audio data are a production of both form and content, and it is worth taking care over the practices we use to preserve our collections in case we overlook the significance of this point and lose something valuable – culturally, historically and technologically.

Sep

2013

Magnetic Reel to Reel Tape and New Transfer Machines – Pictures from the Greatbear Studio

The Greatbear studio always has a wealth of interesting material in it, that somehow have survived the test of time.

From racks stacked full of obsolete audio and video tape machines, to the infinite varieties of reel-to-reel tape that were produced by companies such as Scotch, E.M.I. and Irish Recording Tape.

As objects in themselves they are fascinating, instilled with the dual qualities of fragility and resilience, the boxes worn at the edges and sometimes marked with stamps, identificatory stickers or scrawled, handwritten notes.

A selection of ‘audio letters’ sent to us by a customer

The latest addition to the Great Bear Studio – the Fostex Model 80 8 Track Recorder

Sep

2013

Curating Digital Information or What Do You With Your Archive?

Today is the first day of iPres 2013, the 10th international conference on the preservation of digital objects held in Lisbon, Portugal. To mark the occasion we want to reflect on an issue that is increasingly important for the long term management of digital data: curation.

Anyone who has lived through the digital transition in the 21st century surely cannot ignore the information revolution they have been part of. In the past ten years, vast archives of analogue media have been migrated to digital formats and everyday we create new digital information that is archived and distributed through networks. Arcomen, who are running a workshop at iPres on ‘Archiving Community Memories’, describe how

‘in addition to the “common” challenges of digital preservation, such as media decay, technological obsolescence, authenticity and integrity issues, web preservation has to deal with the sheer size and ever-increasing growth and change rate of Web data. Hence, selection of content sources becomes a crucial and challenging task for archival organizations.’

As well as the necessary and sometimes difficult choices archival organisations have to make in the process of collecting an archive, there is then the issue of what to do with your data once it has been created. This is where the issue of digital curation comes in.

Screenshot of the SONY website from 1996

Traditionally, the role of the curator is to ‘take care’ and interpret collections in an art gallery or a museum. In contemporary society, however, there is an increasing need for people to curate collections that are exclusively digital, and can only be accessed through the web. Part of any long term digitisation strategy, particularly if an archive is to be used for education or research purposes, should therefore factor in plans and time for curation.

Curation transforms a digital collection from being the equivalent of a library, which may be searchable, organised and catalogued, into something more akin to an exhibition. Curation helps to select aspects of an archive in order to tell deliberate stories, or simply help the user navigate content in a particular way. Curating material is particularly important if an archive deals with a specialist subject that no one knows about because visitors often need help to manoeuvre large amounts of complex information. Being overwhelmed by content on the internet is an often cited expression, but ensuring digital content is curated carefully means it is more likely that people visiting your site will be able to cope with what they find there, and delve deeper into your digitsed archival treasures.

Like all things digital, there is no one steadfast or established guidelines for how to ensure your collection is curated well. The rapid speed that technology changes, from preferred archival formats, software to interface design, mean that digital curation can never be a static procedure. New multiple web authoring tools such as zeega, klynt and 3WDOC will soon become integrated into web design in a similar fashion to the current Web 2.0 tools we use now, therefore creating further possibilities for the visual, immersive and interactive presentation of digital archive material.

Screenshot of the Fostex website from Dec 1998

Curation is an important aspect of digital preservation in general because it can facilitate long term use and engagement with your collection. What may be lost when archive sites become pruned and more self-consciously arranged is the spontaneous and sometimes chaotic experience of exploring information on the web.

Ultimately though, digital curation will enable more people to navigate archival collections in ways that can foster meaningful, transformative and informative encounters with digitised material.

Aug

2013

The Magnetist – Audio Cassettes in Contemporary Culture

As lovers of magnetic tape and obsolete media, we keep our eyes open for people who remain attached to the formats most have forgot.

A recent film posted on Vimeo features the creative life of part time chef, noise musician and tape DJ Micke, also known as ‘The Magnetist’.

The film follows the Stockholm-based artist through his life as a ‘tapeologist.’ From demagnetising tape in order to create soundscapes, to running a club night comprised of tapes scavenged from wherever he can find them, Micke demonstrates how the audio cassette remains a source of inspiration within counter culture.

The Magnetist from Filibuster on Vimeo.

The wider resurgence of cassettes is evident from the forthcoming Cassette Store Day, an event that will be marked in record stores in the UK, USA, Europe and South America.

New tape labels are popping up all the time. Tapes are now often preferred to CD-Rs for short run albums in do it yourself punk culture, as releases blur the line between art object and collector item.

So what’s behind the sub-cultural obsession with the audio cassette tape? Perhaps it is no more complex than novelty value and nostalgia. It may however be evidence of the persistence of analogue technologies in an era where digital technologies appear to have colonised our relationship to sound and vision.

Is there a yearning to resist the ways digital media shapes how we listen to music, both at the level of sound quality, and the promiscuous skipping through mp3 files?

You simply can’t do that with tape. You have to rewind, fast forward or listen the whole way through. Its a mechanical process, often shrouded in hiss.

What is certain, fashion or no fashion, the wheels on the Great Bear tape machines will keep turning.

Aug

2013

C-120 Audio Cassette Transfer – the importance of high quality formats

In archiving, the simple truth is formats matter. If you want the best quality recording, that not only sounds good but has a strong chance of surviving over time, it needs to be recorded on an appropriate format.

Most of us, however, do not have specialised knowledge of recording technologies and use what is immediately available. Often we record things within limited budgets, and need to make the most of our resources. We are keen to document what’s happening in front of us, rather than create something that will necessarily be accessible many years from now.

At the Great Bear we often receive people’s personal archives on a variety of magnetic tape. Not all of these tapes, although certainly made to ensure memories were recorded, were done on the best quality formats.

Recently we migrated a recording of a wedding service from 1970 made on C-120 audio cassette.

Image taken using a smart phone @ 72 dpi resolution

C60 and C90 tapes are probably familiar to most readers of this blog, but the C-120 was never widely adopted by markets or manufacturers because of its lesser recording quality. The C-120 tape records for an hour each side, and uses thinner tape than its C90 and C60 counterparts. This means the tape is more fragile, and is less likely to produce optimum recordings. Thinner tapes is also more likely to suffer from ‘print-through‘ echo.

As the Nakamichi 680 tape manual, which is pretty much consulted as the bible on all matters tape in the Great Bear studio, insists:

‘Choosing a high quality recording tape is extremely important. A sophisticated cassette deck, like the 680, cannot be expected to deliver superior performance with inferior tapes. The numerous brands and types of blank cassettes on the market vary not only in the consistency of the tape coating, but in the degree of mechanical precision as well. The performance of an otherwise excellent tape is often marred by a poor housing, which can result in skewing and other unsteady tape travel conditions.’

The manual goes on to stress ‘Nakamichi does not recommend the use of C-120 or ferrichrome cassettes under any circumstances.’ Strong words indeed!

It is usually possible to playback most of the tape we receive, but a far greater risk is taken when recordings are made on fragile or low quality formats. The question that has to be thought through when making recordings is: what are you making them for? If they are meant to be a long term record of events, careful consideration of the quality of the recording format used needs to be made to ensure they have the greatest chance of survival.

Such wisdom seems easy to grasp in retrospect, but what about contemporary personal archives that are increasingly ‘born digital’?

A digital equivalent of the C-120 tape would be the MP3 format. While MP3 files are easier to store, duplicate and move across digital locations, they offer substantially less quality than larger, uncompressed audio files, such as WAVs or AIFFs. The current recommended archival standard for recording digital audio is 24 bit/ 48 kHz, so if you are making new recordings, or migrating analogue tapes to digital formats, it is a good idea to ensure they are sampled at this rate

In a recent article called ‘3 Ways to Change the World for Personal Archiving’ on the Library of Congress’ Digital Preservation blog, Bill LeFurgy wrote:

‘in the midst of an amazing revolution in computer technology, there is a near total lack of systems designed with digital preservation in mind. Instead, we have technology seemingly designed to work against digital preservation. The biggest single issue is that we are encouraged to scatter content so broadly among so many different and changing services that it practically guarantees loss. We need programs to automatically capture, organize and keep our content securely under our control.’

The issue of format quality also comes to the fore with the type of everyday records we make of our digital lives. The images and video footage we take on smart phones, for example, are often low resolution, and most people enjoy the flexibility of compressed audio files. In ten years time will the records of our digital lives look pixelated and poor quality, despite the ubiquity of high tech capture devices used to record and share them? Of course, these are all speculations, and as time goes on new technologies may emerge that focus on digital restoration, as well as preservation.

Ultimately, across analogue and digital technologies the archival principles are the same: use the best quality formats and it is far more likely you will make recordings that people many years from now can access.

Jul

2013

Greatbear Studio Visit – Archive for Mathematical Sciences and Philosophy

This week in the Greatbear Studio we are being visited by Michael Wright, Director of The Archive Trust for Research in Mathematical Sciences and Philosophy.

The Archive Trust for Research in Mathematical Sciences and Philosophy holds an extensive collection of audio and video recordings on subjects in mathematics, physics and philosophy, particularly the philosophy and foundations of mathematics and the exact sciences recorded since the early 1970s.

The website explains further the rationale for collecting the recordings:

Such recordings allow historians of science and mathematics to form a better appreciation of the background to the emergence of new ideas; and also of the complex pattern formed by “roads not taken” – ideas which for whatever reason were laid aside, or apparently subsumed in other developments. Those ideas may later re-emerge in ways yielding a new perspective on those developments. Such a rich archive of primary oral source material naturally aids historical study of the Sciences and the conceptual and philosophical questions to which they give rise.

The project started in 1973 when Michael recorded lectures, seminars and courses relating to Maths and Philosophy when he was a doctoral student. The early recordings were made in Oxford, London and Cambridge and were done on an enthusiastic, if amateur basis. In the 1980s and 1990s the recording process became more systematic, and more video recordings were taken. The archive is still collecting material, and Michael often travels to conferences and lectures to record contemporary debates in the field, as he is this week when he travels to Warsaw for Samuel Eilenberg Centenary conference (there are recordings of Eilenberg’s lectures and an interview collected in the archive).

What started as a hobby for Michael has now become a full time commitment. The archive contains a staggering 37,000 recordings, those he made and ones solicited from other individuals. They include recordings of figures such as Imre Lakatos, Ilya Prigogine, contemporary philosopher Alain Badiou and many more.

The majority of recordings from 1973-2003 were recorded on audio cassette format, although some were done on reel-to-reel recorders. Many of these recordings remain on analogue tape, and the biggest challenge for the archive is now to find the funds to migrate several thousand hours of recordings to digital format.

The archive also track downs and publishes existing material that may be collected in other archives, or are stored in people’s personal collections. For Michael the biggest revelation in constructing the archive was finding out about the amount of material people have that are sitting in the back of their cupboards. This is either because people have forgotten they exist, or because they simply do not known what to do with them.

The archive became a charitable trust in 2008 and names among its trustees English mathematical physicist and philosopher Sir Roger Penrose, and Martin Rees, former Master of Trinity College and Emeritus Professor of Cosmology at the University of Cambridge and President of the Royal Society.

Its an exciting, and transitional, time for the archive as it plans to take its next steps. In the coming years there are plans to develop the website through uploading ‘born digital’ information, attain funds for wholesale digitisation of tape and paper resources and continue to collect recordings. This ambitious project is well on its way to becoming a vital and unique contribution to the subject, and will interest many other people who are simply curious about these rich and complex topics.

Jul

2013

How sustainable is digitisation?

Often when we think about the reasons to digitise magnetic tape collections we are considering the future. We digitise to make material accessible so it can be used again, or to preserve it so subsequent generations can benefit or learn from it. But how sustainable is digitisation and digital technology? What is the ecological impact of the widespread and breathtakingly fast adoption of digital technologies since the late 1990s?

At an everyday, consumer level, the use of digital technologies comes with real human and environmental costs, as Professor Toby Miller and Professor Richard Maxwell demonstrate in a recent article in The Guardian. They argue that the very metaphors we use to describe digital media – ‘virtual,’ ‘cloud’, ‘streams’ and ‘mobiles’ – dangerously obscure the fact they come from materials, such as the minerals Tatalun, Tungsten, Tin and Gold, and cover up the exploitative labour conditions, and war torn situations from which they are extracted:

‘Suggestions that we live in a dematerialised world are not only exaggerated; they are doing more harm than good. One person’s cloud is another’s pollution, and one person’s mobile is another’s enslavement. From electronic waste to conflict minerals, the new media leave an indelible mark on bodies and the Earth they inhabit.’

The extent of violence and exploitation that lie at the end of the digital supply chain is hardly a secret. At a consumer level there seems to be very little resistance to the use of mobile digital devices, probably because our very social existence is dependent upon them in a culture where media is pervasive. It is not easy to opt out, and what would you do if you did?

As heavy users of digital technologies we walk with our heads in the clouds, so to speak, unable to access the wider environmental impact of our actions. This impact is intensified by the pressure to continually upgrade our devices, as Dr Chris Priest writes,

‘the regularity with which you replace a device becomes more important in determining the overall footprint of the device. If we take a hypothetical device with a 50% use footprint, and replace it after two years rather than three, then it will increase our overall footprint by 25%. Of course, new devices might be becoming increasingly efficient and this could offset the increase to some extent. Though even if the new device used no power, it could not offset it completely.’

Yet these are speculations not empirical fact. It is hard to know concretely what the environmental consequences of becoming immediate adopters of the latest (fastest, smallest, bestest) digital technologies are. One thing is certain, new goods will appear and people will be told they can’t live without them. This is how an economy driven by innovation works.

Thinking about the uptake of digital technologies at an institutional level, it is clear that within a technological climate pre-disposed to the production of ‘digital waste’ and obsolescence, the mismanagement of energy resources in order to keep digital data ‘alive’ (that is useable, accessible) is a real possibility. One only need turn to the financial and technological waste produced from the BBC’s Digital Media Initiative (DMI) to confirm that the creation of technical systems devised to manage large digital archives are not moving at the same relentless speed as the neoliberal market.

Which begs the question: can there be an ecological solution to the problem of digitisation, and the use of digital technologies in an innovation/ obsolescence economy? Can digitisation ever be energy efficient, non-exploitative and flexible enough to cope with the technological changes that will inevitably happen? What would a sustainable and ethical approach to digital information management look like?

As our world gets increasingly networked these are pressing questions effecting everyone. And clearly understanding the wider impact of the use of technology on people and the earth is a serious issue, usually forgotten when scrolling through data feeds in a voracious, but often distracted, manner. These are admittedly big questions and we welcome comments, links and ideas on how to answer them.

As keen hoarders of mechanical waste from the analogue era who are passionate about making data accessible in digital form, we are contributing to a world that places unprecedented value on technological information.

Need this, however, always be at the expense of people and the world we share as currently it seems to be?

Jul

2013

What is the future of analogue media?

In a recent blog article on the Presto Centre website, Richard Wright argues that ‘the audiovisual collections of the 20th century were analogue, and we are now at a critical time for considering the digital future of that analogue content.’ He goes on to say, emphatically:

‘All analogue audio and video formats are obsolete. Digital content walks through walls, travels at the speed of light, can be in many places at the same time, and can (with care) be perfectly copied, again and again. So digitisation has become the solution to the obsolescence of all analogue audio and video formats.’

Although careful not to make too clinical a statement, he bookmarks 15 April 2023 as the date when analogue obsolescence really kicks in.

We have written extensively on this blog about the problem of obsolescence, and how we collect machines and learn the skills to fix them.

A major problem is finding spare parts for machines after manufacturers stop producing them. Many components were made according to very precise specifications that are hard to make from scratch. When machines and their parts wear out it will therefore be difficult, if not impossible, to keep them working.

This means that the cost of transfers will rise due to machine scarcity. At an institutional level this may lead to selective decisions about what gets digitised and what doesn’t.

There is one analogue format that has flourished in the 21st century: vinyl.

Writing for music magazine The Wire, Numero Group’s Rob Sevier and Ken Shipley describe how ‘vinyl’s violent sales spike has been a lonely bright spot in what has been a 14 year deterioration in sales of recorded music’.

Yet the resilience of vinyl and other contemporary fringe uses of analogue media, such as the cassette tape and floppy disk, is not enough to stop the march of digitisation. For experts like Wright the digital future for the majority of people is inevitable, irresistible even, given how it enables collections to be open, replicable and accessible.

Yet committing to digital technologies as a preservation and access strategy does not solve our information problems, as we have been keen to stress on this blog. There is also a worrying lack of long term strategy for managing digital information, a problem which is ever more pronounced in film preservation where analogue tape is still marked as the original from which digital copies are made.

It is clear that the information we create, store and use is in transition. It probably always has been. The emergence of digital technologies has just made this a pressing issue, not only for large institutions, but for people as we go about our day to day lives.

‘Digitise now!!’ is Richard Wright’s advice – and of course we agree.

Jul

2013

4 track 1/4 inch reel to reel tape recorded in mono – The Couriers Folk Club, Leicester

We were recently sent a ¼ inch tape by Ed Bates that included recordings from the Couriers Folk Club in Leicester, which ran from Autumn 1964 – June 1974.

The tape features performances from The Couriers (Jack Harris and Rex Brisland), George and Thadeus Kaye, Bill Pickering, Mark Newman and Mick Odam.

Jack Harris, who alongside Rex Brisland ran the club, describes how ‘traditional singers like Bert Lloyd, Ewan MacColl and Pete Seeger, Bob Davenport were regular visitors together with ageing ploughboys, miners and fishermen who were often so infirm or unlikely to make their own way to Leicester they had to be fetched by car.’

As well as supporting grassroots folk music from the local area, well known performers such as musical superstar Barbara Dickson, Paul Simon and Joni Mitchell graced the stage.

The tape recordings we received span five years. The first recording was made on 6 August 1966, then 3 September 1966, 8 February 1970 and finally 9 April 1971.

Each performance was recorded on a separate track in mono. This means that the 7” long spool contains 8 hours of music!

Like today’s MP3 digital files, the quality of the recorded sound is compromised because so much information is squeezed into a smaller space on the tape. A better quality recording would have been made if all four channels were used for a single performance, rather than one track for each performance.

The speed at which recordings were made also effects the quality of the recordings, simply because you can record more information per second at a faster rate. The tapes we were sent were recorded at 7 ½ per second on what is likely to have been a domestic tape recorder such as the Sony TC-263D. Ed’s letter to us speaks volumes about the conditions in which the recordings were made:

‘I was present at the Couriers Folk Club in Leicester when they were recorded so I can say that the recording quality is not good. The Sony recorder was used as an amplifier and on some occasions (if someone remembered) a tape was recorded.’

While the recordings certainly would have benefited from less haphazard recording conditions, the quality of the transfer is surprisingly crisp, as you can hear from this excerpt.

Excerpt from the digitised recordings of the Couriers folk club

The tape was in good condition, as Philips magnetic reel-to-reel tape often survives well over time, which aided a good transfer. One thing we were especially attentive to in the transfer process was carefully adjusting the azimuth, because of the slow speed of the original recording and the narrow track width.

Image taken from the BASF magnetic tape manual that illustrates how four tracks can be recorded on magnetic tape

The emergence of recordings of the Couriers Club is especially timely given the recent launch of the English and Folk Dance Society‘s The Full English online digital archive . This contains a massive 44,000 records and over 58,000 digitised images about English folk history.

With a dozen or more tapes recently found from the Club, we look forward to helping this unique part of cultural heritage become accessible again.

Jun

2013

Digital Preservation – Planning for the Long Term

There are plenty of reflections on the Great Bear tape blog about the fragility of digital data, and the need to think about digitisation as part of a wider process of data migration your information will need to make in its lifetime.

We have also explored how fast moving technological change can sometimes compromise our capacity to construct long term strategies for the survival of digital data.

This why it is so important that organisations such as the Digital Preservation Coalition, founded in February 2002, articulate a vision that aims to make ‘digital memory accessible tomorrow.’ Their website goes on to say:

Our generation has invested as never before in digital resources and we’ve done so because of the opportunity they bring. They have grown in volume, complexity and importance to the point that our children are baffled by the inefficiencies of the analogue age. Pervasive, fluid and fragile: digital data is a defining feature of our age. Industry, commerce, government, law, research, health, social care, education, the creative industries, the heritage sector and private life depend on digital materials to satisfy ubiquitous information needs and expectations. Digital preservation is an issue which all organisations, particularly in the knowledge sector, will need to address sooner or later.

As providers of a digitisation service it is important for us to understand digitisation in line with the ideas articulated above. This means creating high quality, uncompressed files that will make it as easy as possible for data migrations to happen in the future should they need to.

Organisations such as the Digital Preservation Coalition are providing sensible advice and creating forums for learning and debate about the problems and possibilities of digital preservation.

These are two things that are needed as we come to navigate an information environment heavily populated by ‘pervasive, fluid and fragile’ digital data.

Jun

2013

‘Mysterious little reddish-brown ribbon’: BASF Magnetic Recording Tape

‘It seems we are living in an age in which practically every dream comes true. At no time in the past have so many scientific discoveries and inventions changed our way of life and the face of the world. Yes, we live in the age of science! Maybe we are forgetting to be awed, or are we so used to acquainting ourselves with the new that we seem to take anything for granted nowadays?’

This is the opening paragraph to A Comprehensive Booklet on BASF Magnetic Recording Tape, published c.1965 by the German company BASF.

The booklet, that we will feature more of in later posts, offers advice and instructions on how to record sound on magnetic tape.

While in today’s culture we may well have forgotten ‘to be awed’ by sound recording technology, there was a time when home recording was an extremely novel activity. As our recent post about Brian Pimm-Smith’s tapes demonstrates, sound recording was done by enthusiasts – it was by no means an everyday activity.

Tape recording clubs were however very popular in the 1960s-1970s, with groups forming all around the country.

Sound artist Mark Vernon describes how ‘dedicated amateurs would meet and swap tips, exchange recordings, enter competitions and arrange activities such as field recording trips. Eager members would lug heavy reel-to-reel recorders around the countryside, to church concerts, fire stations, airports and carnivals to capture the sounds around them.’

The excitement of recording sound on a ‘mysterious little reddish-brown ribbon’ is clear from reading the BASF manual. There is no shortage of awe for the ‘magic tape that practically does everything from writing out cheques to guiding missiles in space.’

In contemporary western culture the use of recording technologies has become as common as eating or breathing. Mystery and magic are words not often used to describe our laptops, phones or tablets. Yet it may well be worth remembering how mysterious and magic technology can be. That the things we take for granted as part of our everyday lives were once new inventions that radically transformed perceptions and our ability to document the world we live in.

As the BASF manual enthused, ‘the multitude of different impressions in the acoustic world…are just as beautiful and gratifying as those of the visible world [and] can now be conserved for all posterity.’

Jun

2013

Repairing obsolete media – remembering how to fix things

A recent news report on the BBC website about recycling and repairing ‘old’ technology resonates strongly with the work of Greatbear.

The story focused on the work of Restart Project, a charity organisation who are encouraging positive behavioural change by empowering people to use their electronics for longer. Their website states,

the time has come to move beyond the culture of incessant electronics upgrades and defeatism in the face of technical problems. We are preparing the ground for a future economy of maintenance and repair by reskilling, supporting repair entrepreneurs, and helping people of all walks of life to be more resilient.

We are all familiar with the pressure to adopt new technologies and throw away the old, but what are the consequences of living in such a disposable culture? The BBC report describes how ‘in developed nations people have lost the will to fix broken gadgets. A combination of convenience and cultural pressure leads people to buy new rather than repair.’

These tendencies have been theorised by French philosopher of technology Bernard Stiegler as the loss of knowledge of how to live (savoir-vivre). Here people lose not only basic skills (such as how to repair a broken electronic device), but are also increasingly reliant on the market apparatus to provide for them (for example, the latest new product when the ‘old’ one no longer works).

A lot of the work of Greatbear revolves around repairing consumer electronics from bygone eras. Our desks are awash with soldering irons, hot air rework stations, circuit boards, capacitors, automatic wire strippers and a whole host of other tools.

We have bookshelves full of operating manuals. These can help us navigate the machinery in the absence of a skilled engineer who has been trained how to fix a MII, U-Matic or D3 tape machine.

As providers of a digitisation service we know that maintaining obsolete machines appropriate to the transfer is the only way we can access tape-based media. But the knowledge and skills of how to do so are rapidly disappearing – unless of course they are actively remembered through practice.

The Restart Project offers a community-orientated counterpoint to the erosion of skills and knowledge tacitly promoted by the current consumer culture. Promoting values of maintenance and repair opens up the possibility for sustainable, rather than throwaway, uses of technology.

Even if the Restart Project doesn’t catch on as widely as it deserves to, Greatbear will continue to collect, maintain and repair old equipment until the very last tape head on earth is worn down.

Jun

2013

Digitising Audio Tape – Process, Time & Cost

Last week we wrote about the person time involved in transferring magnetic tape to digital files, and we want to tell you more about the processes involved in digitisation work.

While in theory the work of migrating media from one format to another can be simple, even the humble domestic cassette can take a substantial amount of time to transfer effectively.

Doing transfers quickly would potentially keep the costs of our work down, but there are substantial risks involved in mass migrations of tape-based material.

Problems with digital transfers can occur at two points: the quality of the playback machine and the quality of the tape.

Let’s focus on the playback machine.

Each time a cassette is transferred we have to ensure that the cassette deck is calibrated to the technical specification appropriate to that machine. Calibration is a testing procedure where a standard test tape is used to set the levels for tape to be digitised. The calibration process allows us to check tapes are played back at the correct speed and audio levels, that wow and flutter levels are set and the azimuth is aligned.

Azimuth refers to the angle between the tape head(s) and tape. Differences in Azimuth alignment arise from the azimuth of the original recording. You cannot know this information from just looking at a tape and you will get a sub-optimal transfer unless you adjust your machine’s azimuth to match the original recording.

Regularly checking the Wow and Flutter on the tape machine is also very important for doing quality transfers. Wow and flutter refer to fluctuations in speed on the playback mechanism, flutter being a higher rate version of wow. If you have listened to a tape you will probably be familiar with the sound of warped and woozy tape – this is the presence of wow. All tape machines have wow and flutter, but as components in the mechanisms stretch there is the potential for wow and flutter to increase. It is therefore essential to know what level the wow and flutter are set on your tape deck –less than 0.08% Weighted Peak on our Nakamichi 680 machines – to ensure optimal transfer quality.

Not all cassette machines were made equal either, and the quality of playback is absolutely dependent on the type of machine you have. There is a massive difference between the cheap domestic cassette machines made by Amstrad, to the cassette decks we use at Great Bear. Nakamichi machines were designed to squeeze the most out of the cassette, and their performance is way above the standard ‘two head’ cheap domestic machines.

Even with a Nakamichi deck, however, they have to be regularly checked because they are fragile electromagnetic machines that will drift out of specification over time. When machines drift they slip out of alignment, therefore effecting their operating capacity. This can occur through subtle knocks, everyday wear and tear and general ageing of mechanical and electrical components. For example, with extended use the grease in the components dries up and goes hard, and therefore affects the movement of the mechanisms.

Problems can also arise with the tapes themselves.

Most issues arise from tapes not being played back in well calibrated machines.

With audio cassettes the potential for azimuth error is increased because the speed the tape moves pasts the head is very slow. The tape therefore needs to be assessed to see if it is in a playable condition. It is played back in mono because it is easier to hear if there are problems with the azimuth, and then the azimuth is manually adjusted on the machine.

Migrating tape is unquestionably a ‘real time’ process. You need to listen and monitor what’s on the tape and the digitised version to ensure that problems with the transfer are detected as it is happening. It is a very hands on activity, that cannot be done without time, care and attention.

Jun

2013

From digital files back to analogue tape

The bread and butter work of Greatbear Analogue and Digital Media is to migrate analogue and digital magnetic tape to digital files, but recently we were asked by a customer to transfer a digital file to ¼ analogue tape.

The customer was concerned about the longevity of electronic digital formats, and wanted to transfer his most valued recordings to a tangible format he knew and trust. Transferring from digital to analogue was certainly more expensive: the blank tape media cost over £50 alone.

In a world where digital technology seems pervasive, remaining so attached to analogue media may appear surprising. Yet the resilience of tape as a recorded medium is far greater than is widely understood.

Take this collection of old tapes that are in the back yard of the Greatbear office. Fear not customers, this is not what happens to your tapes when you send them to us! They are a collection of test tapes that live outside all year round without shelter from the elements. We use them to test ways of treating degraded tapes because we don’t want to take unnecessary risks with our customers’ material.

Despite being subject to pretty harsh conditions, the majority of material on these tapes is recoverable to some degree.

Would digital data stored on a hard drive survive if it had to endure similar conditions? It is far less likely.

Due to its electronic composition digital data is fragile in comparison with analogue magnetic tape. This is also the ironic conclusion of Side by Side (2012), the documentary film narrated by Keanu Reeves which explores the impact of digital technology on the film industry.

Requests for digital to analogue transfers are fairly rare at Great Bear, but we are happy to do them should the need arise!

And don’t forget to back up your digital files in at least three different locations to ensure it is safe.

Jun

2013

Real time transfers – digitising tape media

In theory the work we do at Greatbear is very simple: we migrate information from analogue or digital magnetic tape to electronic digital files.

Once transferred, digital files can be easily edited, tagged, accessed, shared or added to a database. Due to the ubiquitous nature of digital media today, if you want to use your data, it needs to be in a digital form.

In practice however, there are a lot more issues that arise when migrating tape based media. These can stem from the obsolescence of machines (spare parts being a particular issue), physical problems with the tape and significantly, the actual person-time involved in doing the transfer.

While large institutions like the Library of Congress in USA can invest in technology that enables mass digitisation like those developed by Samma Systems, most transfers require operators to do the work. The simple truth is that for fragile and obsolete tape media, there is no other option. In the film ‘Living Archive – Preservation Challenge‘ David Crostwait from American digitisation company DC Video describes the importance of careful, real time transfers:

‘When a tape is played back, that tape starts from the very beginning and may run for 60-65 minutes straight. One person sits in front of that machine and watches that tape from beginning to end, s/he does nothing else but watch that tape. We feel this procedure is the only way to guarantee the highest quality possible.’

At Greatbear we echo this sentiment. We give each transfer individual attention so that the information is migrated accurately and effectively. Sometimes this means doing things slowly to ensure that tape is spooled correctly and the tension within the tape pack is even. If transfers are rushed there is always the danger that tape could get crumpled or damaged, which is why we take our time.

Jun

2013

Archiving for the digital long term: information management and migration

As an archival process digitisation offers the promise of a dream: improved accessibility, preservation and storage.

However the digital age is not without its archival headaches. News of the BBC’s plans to abandon their Digital Media Initiative (DMI), which aimed to make the BBC media archive ‘tapeless’, clearly demonstrates this. As reported in The Guardian:

‘DMI has cost £98.4m, and was meant to bring £95.4m of benefits to the organisation by making all the corporation’s raw and edited video footage available to staff for re-editing and output. In 2007, when the project was conceived, making a single TV programme could require 70 individual video-handling processes; DMI was meant to halve that.’

The project’s failure has been explained by its size and ambition. Another telling reason was cited: the software and hardware used to deliver the project was developed for exclusive use by the BBC. In a statement BBC Director Tony Hall referred to the fast development of digital technology, stating that ‘off-the-shelf [editing] tools were now available that could do the same job “that simply didn’t exist five years ago”.’

The fate of the DMI initiative should act as a sobering lesson for institutions, organisations and individuals who have not thought about digitisation as a long, rather than short term, archival solution.

As technology continues to ‘innovate’ at startling rate, it is hard to predict how long the current archival standard for audio and audio-visual will last.

Being an early adopter of technology can be an attractive proposition: you are up to date with the latest ideas, flying the flag for the cutting edge. Yet new technology becomes old fast, and this potentially creates problems for accessing and managing information. The fragility of digital data comes to the fore, and the risk of investing all our archival dreams in exclusive technological formats as the BBC did, becomes far greater.

In order for our data to survive we need to appreciate that we are living in what media theorist Jussi Parikka calls an ‘information management society.’ Digitisation has made it patently clear that information is dynamic rather than stored safely in static objects. Migrating tape based archives to digital files is one stage in a series of transitions material can potentially make in its lifetime.

Given the evolution of media and technology in the 20th and 21st centuries, it feels safe to speculate that new technologies will emerge to supplant uncompressed WAV and AIFF files, just as AAC has now become preferred to MP3 as a compressed audio format because it achieves better sound quality at similar bit rates.

Because of this at Greatbear we always migrate analogue and digital magnetic tape at the recommended archival standard, and provide customers with high quality and access copies. Furthermore, we strongly recommend to customers to back up archive quality files in at least three separate locations because it is highly likely data will need to be migrated again in the future.

May

2013

Digitising & Restoring Personal Archives – 1/4 inch reel to reel audio tape

In today’s digital society most people have an archive. On personal computers, tablets and mobile devices we store, create and share vast amounts of information. We use archives to tell others about our lives, and the things that are important to us.

Gone are the days when archives were dusty, dark places where experts went to research esoteric knowledge. Archives are everywhere. They are dynamic, digital and personal, as well as being institutional, historical, corporate and civic.

The creation of personal archives is of course nothing new, but the digital age forces us to have a far more intimate relationship with information, and its organisation. Put simply, there is loads more information, and if it isn’t collected in a systematic way you may well drown in a sea of your own, not to mention everybody else’s, data. Maybe this is happening to you right now! If so, you need to embrace the archival moment and get your own collections in shape.

Part of this everyday information management is migrating archives stored on obsolete formats, such as the many different types of analogue and digital magnetic tape we work with at Greatbear. Digitising tape gives it new life, allowing it to be easily circulated, shared and used with today’s technologies.

A significant amount of the Greatbear’s work involves digitising the diverse collections people produce in their everyday working, creative and social lives.

Here are two recent digitisation projects which are a good example of our work.

Swansea Sound 1976

We were sent a number of ¼ inch reel to reel Scotch 3M tape ‘made for the BBC’ tape, recorded at the rate of 7 ½ inches per second from local radio station Swansea Sound in 1976. The tapes were all in good condition, although the boxes had some evidence of water damage. Over time the tension in the tape pack had also changed, so they required careful re-spooling before being played.

The recordings were fascinating to digitise because they communicated how little the format of radio programmes have changed since the late 1970s. Jingles, news reports, chat and music were all part of the show, and anyone familiar with BBC Radio 2 would certainly enjoy the recordings, that still seem to be played every Saturday morning!

Brian Pimm-Smith’s recording diaries and tape letters

A collection of Brian’s 1/4 inch tapes

Another collection was sent to us from Brian Pimm-Smith. Brian enthusiastically documented his life and work activities using a Uher open reel portable tape recorder which he acquired in 1963. The box included many ¼ inch tapes that could record up to 10 minutes at 3 and ¾ inches per second. These tapes could also record up to 4 mono tracks at 10 minutes each, allowing for storage of up to forty minutes at a time. The main bulk of the collection is a series of spoken letters sent to and from Pimm-Smith and his family, who between them lived in Britain, Pakistan, Rhodesia (now Zimbabwe), Japan and Saudi-Arabia, but it also includes recordings of when Brian worked taking weather measurements for the British Antarctic Survey.

Some of the 1/4 inch tapes were marketed by companies such as Scotch and EMI specifically to be used as ‘voice letters’ that ‘links absent friends’. Despite this Pimm-Smith said that making such recordings was pretty rare, something ‘quite out there’ for most people. Brian’s mother nonetheless embraced the activity, as they shared correspondence back and forth between wherever they lived at the time.

Voice Letters

The 1/4 inch tape boxes in themselves are a colourful record of international postage in the late 1960s. Sent from Pakistan, Rhodesia (now Zimbabwe), Saudi Arabia, Australia and Japan, the small boxes are plastered with stamps. The boxes were reinforced with sellotape to ensure the contents didn’t fall out (which is still stuck fast to the boxes, by the way, clearly demonstrating the surprising longevity of some forms of sticky tape). Pimm-Smith’s tapes are fascinating objects in themselves that bear the marks of travel through space in the form of postal stamp marks, and time, as they sit on the desk now in the Greatbear Studio.

Perhaps the most exciting and unique recording Brian has kept is the audio diary of his trip through the Sahara desert. For the trip Brian drove an early 70s Range Rover which had a cassette player-recorder, a technological device only available in Africa which used audio cassette tapes. This enabled him to document his impressions as he drove along. Brian describes how he had taken a portable typewriter with the intention of keeping a written diary, but he used the tape recorder because it was more ‘immediate.’ On hearing the digitised tapes Brian was amazed at how clear the recordings sound today, particularly because he was driving at the same time and there was likely to be background noise. You can hear the hum of the car engine in the extract below, but the voice is still clearly very audible.

http://thegreatbear.co.uk/wp-content/uploads/blog-example-cassette-tape-1.mp3

Listen to Brian talk about problems with his tyre as he drove across the Sahara Desert in 1976

The stories Swansea Sound radio and Pimm-Smith’s collection tell are part of wider social histories. They tell us about communities and places, as well as the continuities of style in broadcast radio. They tell us how people used analogue tape recordings to document personal adventures and communicate with families who lived in different countries.

Both tapes are examples of the sheer diversity of personal, magnetic tape based archives that people have been keeping for years, and which we digitise at the Greatbear. Brian Pimm-Smith contacted Greatbear because he wanted to make his tapes accessible, and preserve them for future use. He is hoping one day to write a book from his many adventures and these recordings can now remind him not only of what he did, but how he felt in the moment he made them.

May

2013

Audio cassette transfer and Martin Parr’s The Non Conformists

We were recently sent a collection of recorded interviews with residents of Hebden Bridge, a mill town in the Pennines. They were recorded on regular, domestic tapes of the mid-1970s, the kind that were sold in shops such as Woolworths or WHSmith.

As magnetic cassette tapes go, these cheaper tapes can often deteriorate at a fast rate because they were aimed at a mass consumer market, and therefore not made with longevity in mind. These tapes however were in excellent condition, and no issues arose in the digitisation process.

Here is what Susie Parr told us about the project behind the tapes, and the publishing plans for the material later this year. We were very happy to be part of a creative project that will enable the stories to be shown to new audiences because of digitisation.

‘In 1975 photographer Martin Parr moved to Hebden Bridge, a mill town in the Pennines, with some friends from art school in Manchester. In a project that was to last five years, he started photographing the area, documenting a traditional culture and way of life that were slowly declining. Susie Mitchell, who also lived in Hebden Bridge, wrote about the people and places that Martin photographed. Together they built up a record of the day to day lives of mill-workers, game-keepers, coal miners, hill-farmers and chapel-goers. As part of their research, Susie and Martin would tape record their conversations with some of the characters they met. Thirty years later, the elderly audio tapes have been digitised and the photographs and texts are going to be published by Aperture in a book called The Non Conformists. In September, an exhibition will open in London.’

Below is an audio snippet of one of the tapes. This is a raw unprocessed version, notice the tape hiss inherent in these types of recordings. Sympathetic noise reduction to reduce this type of noise, can be process on these file if necessary.

parr-cassette-oral-history-snippet-1975

Apr

2013

8 track cartridges and museum tour

8 track cartridges were a very popular domestic audio format in the United States, although there were also sold in the UK and Europe. The growth of the 8 track was synonymous with its use in car industry, as it allowed people to listen to music on the move.

Although phased out in the early 1980s as CDs became increasingly popular, the 8 track retains a cult following, as demonstrated by this video which takes a virtual tour around the 8 track museum in Dallas, Texas, USA.

At Great Bear we are equipped to transfer 8 track cartridges and NAB cartridges which were used primarily in professional contexts, such as to play jingles at radio stations.

Mar

2013

Delivery formats – to compress or not compress

Screenshot of software encoding a file to MP3 used at the Great Bear

After we have migrated your analogue or digital tape to a digital file, we offer a range of delivery formats.

For video, using the International Association of Sound & Audiovisual Archives Guidelines for the Preservation of Video Recordings, as our guide, we deliver FFV1 lossless files or 10-bit uncompressed video files in .mkv or QuickTime compatible .mov containers. We add viewing files as H264 encoded .mp4 files or DVD. We’ll also produce any other digital video files, according to your needs, such as AVI in any codec; any MacOS, Windows or GNU/Linux filesystem (HFS+, NTFS or EXT3.

For audio we offer Broadcast WAV (B-WAV) files on hard drive or optical media (CD) at 16 bit/44.1 kHz (commonly used for CDs) or 24 bit/96 kHz (which is the minimum recommended archival standard) and anything up to 24 bit / 192 kHz. We can also deliver access copies on CD or MP3 (that you could upload to the internet, or listen to on an ipod, for example).

Why are there so many digital file types and what distinguishes them from each other?

The main difference that is important to grasp is between an uncompressed digital file and a compressed one.

On the JISC Digital Media website, they describe uncompressed audio files as follows:

‘Uncompressed audio files are the most accurate digital representation of a soundwave, but can also be the most resource-intensive method of recording and storing digital audio, both in terms of storage and management. Their accuracy makes them suitable for archiving and delivering audio at high resolution, and working with audio at a professional level, and they are the “master” audio format of choice.’

Why uncompressed?

As a Greatbear client you may wonder why you need a large, uncompressed digital file if you only want to listen to your old analogue and digital tapes again. The simple answer is: we live in an age where information is dynamic rather static. An uncompressed digital recording captured at a high bit and kHz rate is the most stable media format you can store your data on. Technology is always changing and evolving, and not all types of digital files that are common today are safe from obsolescence.

It is important to consider questions of accessibility not only for the present moment, but also for the future. There may come a time when your digitised audio or video file needs to be migrated again, so that it can be played back on whatever device has become ‘the latest thing’ in a market driven by perpetual innovation. It is essential that you have access to the best quality digital file possible, should you need to transport your data in ten, fifteen or twenty years from now.

Compression and compromise?

Uncompressed digital files are sound and vision captured in their purest, ‘most accurate’ form. Parts of the original recording are not lost when the file is converted or saved. When a digital file is saved to a compressed, lossy format, some of its information is lost. Lossy compression eliminates ‘unnecessary’ bits of information, tailoring the file so that it is smaller. You can’t get the original file back after it has been compressed so you can’t use this sort of compression for anything that needs to be reproduced exactly. However it is possible to compress files to a lossless format, which does enable you to recreate the original file exactly.

In our day to day lives however we encounter far more compressed digital information than uncompressed.

There would be no HD TV, no satellite TV channels and no ipods/ MP3 players without compressed digital files. The main point of compression is to make these services affordable. It would be incredibly expensive, and it would take up so much data space, if the digital files that were streamed to televisions were uncompressed.

While compression is great for portability, it can result in a compromise on quality. As Simon Reynolds writes in his book Retromania: Pop Culture’s Addiction to its Own Past about MP3 files:

‘Every so often I’ll get the proper CD version of an album I’ve fallen in love with as a download, and I’ll get a rude shock when confronted by the sense of dimension and spatiality in the music’s layers, the sculpted force of the drums, the sheer vividness of the sound. The difference between CD and MP3 is similar to that between “not from concentrate” orange juice and juice that’s been reconstituted from concentrate. (In this analogy vinyl would be ‘freshly squeezed, perhaps). Converting music to MP3 is a bit like the concentration process, and its done for much the same reason: it’s much cheaper to transport concentrate because without the water it takes up a lot loss volume and it weighs a lot less. But we can all taste the difference.’

As a society we are slowly coming to terms with the double challenge of hyper consumption and conservation thrown up by the mainstreaming of digital technology. Part of that challenge is to understand what happens to the digital data we use when we click ‘save as,’ or knowing what decisions need to be made about data we want to keep because it is important to us as individuals, or to wider society.

At Greatbear we can deliver digital files in compressed and uncompressed formats, and are happy to offer a free consultation should you need it to decide what to do with your tape based digital and analogue media.

Jan

2013

digitising tape issues

The main work of Greatbear is to make analogue and digital tape-based media accessible for people living in a digital intensive environment. But once your tape-based media has been digitised, is that the end of the story? Do you never need to think about preservation again? What issues arise for information management in the future, and how do they relate to our actions in the present?

This year (2013) the National Archives in the UK are facing a huge challenge as the ’20-year rule‘, in which the government will be releasing records when they are 20 years old, instead of 30, comes into effect. A huge part of this process is the digitisation of large amounts of material so they can be easily accessible to the public.

What does this have to do with the digitisation of tape you may be wondering? Well, mostly it provides food for thought. When you read the guidelines for the National Archives’ digitisation strategy, it raises many points that are worth thinking about for everyone living inside an information intensive environment, professional archivist or not. These guidelines suggest that many of the problems people face with analogue media, for example not being able to open, play or use formats such as tape, floppy disks or even digital media, such as a cd-r, do not go away with the move toward wholesale digitisation. This is summed up nicely in the National Archive’s point about digital continuity. ‘If you hold selected digital records that are not yet due for transfer, you will need to maintain their digital continuity. This means ensuring that the records can be found, opened, understood, worked with and trusted over time and through change’. This statement encapsulates the essence of digital information management – the process whereby records are maintained and kept up to date with each technological permutation.

Later on in their recommendations they state something which may be surprising to people who assume that digitisation equates to some form of informational omnipotence: ‘Unlike paper records, digital records are very vulnerable and will not survive without active intervention. We cannot leave digital records on a shelf in an archive – they need active management and migration to remain accessible in the long term.’ These statements make clear that digital records are just as vulnerable as their analogue counterparts, which although subject to degrading, are in fact more robust than is often assumed.

What is the answer to ensuring that the data we create is usable in the future, is there an answer? It is clear on whatever format we choose to archive data there is always risk involved: the risk of going out of date, the risk of vulnerability, the risk of ‘not being able to leave them on the shelf’. Records, archives and data cannot, it seems, simply look after themselves. They have to adapt to their technological environments, as much as humans do.

Dec

2012

greatbear at work

A selection of images from the Greatbear engine room on a typical day at the office.

Repairing, cleaning, baking, testing, sorting and transferring are our daily bread. The work is done to the backdrop of miscellaneous audio and audio-visual recordings ranging from early 1990s house music to ethnomusicological field recordings, corporate archives and everything else in-between.

Studer A 80 Master Studio

Sep

2012

Rare, cassette tape TDK MA-XG

Sep

2012

martyn ford’s master tapes cleaned restored and digitised

We recently had a call from Martyn Ford, acclaimed horn player and arranger on many big albums over the years.

Aug

2012

broken DAT / degraded mouldy tape

Early tape based digital formats such as DAT, Tascam DTRS and ADAT, etc are often problematic now, partly with tape issues and also reliability and spares availability. In 20 or even 10 years time these machines will be much less serviceable than the analogue tape machines of the previous generation and as a result more obsolete and a higher priority to migrate to a file based digital format.

We’ve also started to see a particularly nasty problem with some, and usually the 120 minute length, DATs. The first symptoms are a broken DAT tape usually on wind. The tape pack seems to become slightly sticky, with intermittent tension between the layers of tape and with the thinner tape in 120 lengths this can sometimes break the tape on wind.

You can see in the above image how the tape sticks slightly to the pack and then releases when hand wound. With the greater tension of a machine wind and the tape also wound around the head drum this becomes risky.

With large transfer jobs checking each DAT by disassembly is a mammoth task, but the permanent damage and / or part loss of a section of audio caused by a break is not feasible either!

Jan

2012

Repair Teac A3440 4 track Multitrack Reel to Reel

The Teac A3440 is a classic reel to reel tape recorder from the late 1970s, early ’80s significant in that you could use it to make 4 track multitrack recordings at 15 inches per second, the professional tape recording speed. At the time there was precious little else around at the price to do this so this machine was perfect for small bands and studios who didn’t have the wallet busting amounts needed to buy a larger format 16 or 24 track recorder.

While the A3440 isn’t the last word in high quality analogue recording it has had some significant users in the past none less than Lee Perry who’d used the earlier but similar A3340 on his Heart of the Congos album.

the problems

This machine didn’t initially look heavily used, the heads had little wear but it hadn’t been used in a long while and there was a heavy build up of tape residue on the whole tape path. The capstan was very dirty and in these cases xylene is a more effective cleaner than IPA but don’t get it anywhere near plastic!

This A3340 powered up but the right hand tension arm was hanging at an odd angle and it wouldn’t play or wind.

Time to take it apart – the fake wood sides and rear panels get removed and it’s pretty easy to see what one of the problems is.

A very nasty ‘melted’ rubber capstan belt that took a fair while to scrape and clean off with IPA.

A new belt has purchased online – Teac parts in the UK are a big pain to get hold of through the official channels and I’ve given up contacting them unless I’m desperate for a part I can’t find anywhere else.

The other lack of drive was caused by broken micro switches. When the right hand tension arm is moved up, two micro switches behind the front panel switch power on for the capstan and reel motors. As this arm can get a los of use / abuse it’s common for the micro switches to crack. Both on this example were broken as was the small plastic piece that stops the arm moving too far down.

the repairs

To replace the capstan belt:-

Remove both screws holding the capstan flywheel against the front panel.
Make sure the flywheel is cleaned of all old belt debris.
Make sure the motor wheel is cleaned of all old belt debris.
Refit new belt over small motor wheel, then flywheel.
Replace bracket remove in part 1, making sure you’ve cleaned off the old grease and regreased where the end of the capstan shaft can run.

Although not essential I took the opportunity to remove the whole capstan shaft, clean, check for wear and reoil before putting back. If you do this you will need to reset the endfloat though.

microswitches

It’s not possible or worthwhile trying to repair the microswitches as the modern equivalent that fits perfectly is very cheap. Two were purchased from Farnell and replacement is just a case of:

Unscrew and move away the control PCB to get more space
Make a note of or photograph wiring connections for switches.
Unscrew and carefully desolder the existing microswitches.
Connect wires and solder the new switches in.

The arm end stop was repaired easily with strong super glue and after many hours is still holding.

is it working?

In a word, kind of! The belt and microswitches got the deck and transport moving. It will pull tape and make a noise which is great but an annoying intermittent problem started to appear after some initial testing.

When play or wind are selected, large solenoids clunk and release the reel brakes and move the pinch wheel. This was working BUT occassionally and only in play the right reel brake solenoid didn’t move, leaving the brake on, causing the tape speed to slow, back tension to increase and wow to go crazy!

See our next post for the repair of this problem…

Jan

2012

Quarter inch reel to reel tape audio archiving

We’ve been a bit quiet since last year on our blog here primarily because we have been processing a large, ongoing audio archiving digital migration job for Mood Media Ltd

In essence audio archiving, digital migration, transfer or digitisation, whatever term you prefer, is conceptually simple: one analogue or digital format is moved to another, usually digital, format. It is in the details of this process that things can get complex – requiring experience, specialised tools and often custom-built solutions.

This job has many factors – not just attaining the best analogue transfers, but also addressing the organisation of such a large amount of 10.5″ reels, their digital management once migrated and the creation and management of metadata.

The archive, dating from the 1950s up to the early ’90s, even though it had been stored in less than ideal conditions, is in generally good condition. An interesting and often fantastic-sounding collection of recordings and music are evident all recorded at 15ips in mono, stereo and some encoded with Dolby A noise reduction.

There are specific issues with some tapes that are not uncommon with older audio tape:

Binder hydrolysis or sticky shed syndrome (SSS) has affected a significant proportion of the archive in particular Ampex branded tapes from the 1980s onwards.
Some glue used in spices from the 1980s spreads over time and tends to stick layers of tape adjacent to the splice together. This can be a very frustrating problem which rarely damages the tape permanently, but affects the tape tension on certain sections so that head to tape contact is momentarily lost and a very obvious audio glitch noticed.

The analogue side is important to get correct initially but the management of the data is critical with such a large number of reels and individual artists and tracks. Each batch of tapes would be catalogued in a .csv file. The digital audio transfers were split into individual tracks which then had to be renamed based on the data in the .csv file. This was handled by some php coding which matched the metadata supplied with the files, checking for inconsistencies then renaming the .wav files on one of our servers.

This type of customised workflow can be tricky to setup initially and find the balance between accuracy and speed but once done a smooth workflow is possible maintaining high quality, accuracy and value.

Dec

2011

8 track cassette capstan motor Tascam 238 Syncaset

We specialise in tape transfers, many of which are multitrack cassette tapes.

Tascam, Fostex and Yamaha sold cassette multitrack recorders in the golden days of home recording in the 1980s and ’90s. The 4 track format was especially popular but an 8 track format was also developed that squeezed even more out of the small tape width of the cassette.

We love these cassette formats and their accessibility helped start many musicians’ careers. Unfortunately one of the best 8 track machines, the Tascam 238 Syncaset also suffers from a common and frustrating problem that renders most of these machines useless over time, the dreaded direct drive capstan motor failure…

The 238 and other 8 track and high quality stereo tape decks, the 688 and 122 MkII and III, used a direct drive capstan motor for precise speed control and reduced speed variation or wow and flutter (w/f). The circuit that controls this motor fails in certain ways causing lack of speed control and in our case the capstan motor wizzing away at a crazy speed, not the 9.5 cm/sec that it should do.

This here is the culprit – you can see the attempted repairs which didn’t ultimately work.

One common failure is that the surface mount electrolytic capacitors fail or their capacitance changes to such an extent to cause speed problems. These can be changed for standard through hole caps but you do need to be very careful as the tracks are damaged very easily – good tools are essential.

The other point of failure in the circuit is the BA6304F SO16 IC – we even changed this but the motor still didn’t turn!

There was some suggestion from previous repairers that the grease at the end of the capstan flywheel hardens over time. increasing the friction and causing problems with the circuit.

This can become frustrating quickly, especially when you have a large archive of cassettes to digitise.

When we can’t repair we reluctantly do the next best thing and buy the whole replacement part but this is another exercise in frustration. Teac parts and Teac UK don’t have any european supply of this capstan motor (part no. 53700075-01) anymore as of November 2011. Interestingly about 6 months ago they did at around £60 GBP, then about 3 months ago they had one left at £160 GBP!

Lots of emails later to Teac US, Teac Canada and Teac Japan there seem to be a nice stock still on shelves somewhere and at reasonable prices UNTIL you ask them to ship to the UK when you discover they can’t do this and I’d need to go through Teac UK!!! I’m pretty persistent but I gave up finally even though some of the support staff tried to be pretty helpful.

We find support for older machines from the original manufacturers is not good generally and unreasonably expensive when you can find it. This is similar across audio and video, semi-pro and professional products. Some companies are easier to deal with and have a better parts situation than others, but stockpiling machines, parts, manuals and obsolete knowledge is the best course of action.

What we finally did that worked and was a good solution was purchase 3 Tascam 122 Mk III stereo cassette decks which use the same but a later revision of the capstan motor, (part no. 53700121-00). One machine was donated for the cause and the capstan motor removed, modified and refitted in the 238. The 122 motor has a few factory extras, such as these resistors, shown here:

You also need to solder / desolder the speed pads, to change the motor speed from 4.8 cm/s to 9.6 cm/s that the 238 needs to run at.

It’s also a good idea once you’ve got the capstan motor apart to clean the old grease from the seat, check the end float which can be adjusted using the screw shown on the left and apply new grease to the capstan end.

Put it all back together – be careful to solder the wires to the motor to the correct pads – they’re different on the 122 and test… Ours worked almost perfectly.

As the transport hadn’t been used for a while the reel motor would intermittently stop as if sensing the tape end. This can sometimes be loose counter belts but on the 238 it’s a digitial counter. We cleaned up the leaf switches on the transport top and also sprayed a small amount of deoxit into the inside of the reel motor. A bit more use and it finally worked to spec…

For 4 track and 8 track multitrack cassette transfer, see our dedicated page, and please contact us for more information.

Nov

2011

copy tape to cd, convert video to dvd, is it a good thing?

Digital formats are great and the ease of access and distribution that an Audio CD and a Video DVD offers is fantastic at the moment with cheap players, recorders and personal computers. In the audio and video tape transfer business, getting your business website to rank well in the search engines for key phrases such as ‘copy tape to cd’ or ‘convert video to dvd’ should get you a steady stream of enquiries from people who, primarily, can’t access their tapes any more. The preservation of the valuable recording is usually perceived to be CD or the DVD.

My concerns with the ‘…to CD’ and ‘…to DVD’ process are:

Optical Media that can be burnt using computers, CDr and DVDr, are not as reliable as commercially produced or ‘stamped’ discs and their quality and longevity can vary between different manufacturers.
The digital video stored on a DVD Video is a lossy compressed format that depending on the original footage and if pushed for too much running time can easily make the digital transfer look much worse than the original – not a good reason to transfer the tape!
The everyday nature of audio and video discs and some of the domestic technology we now have has conspired to make what is and can be a complex, time consuming and often problematic process too simple in the eyes of many people.

Since the early marketing of the compact disc in the ’80s by spreading jam on it to highlight its resilience compared to vinyl or tape, many of us have been taken in by this and have a skewed belief on the longevity of CD and DVD optical media. In fact optical media can degrade and become unreadable and unplayable in a very short space of time even with good storage practices. Tape based storage formats of course have their numerous problems but they can often be incredibly resilient over time even in under poor storage conditions. When tape does degrade it is rare event when it cannot be treated and made playable .

CDr and DVDr Longevity

Optical media that can be burnt form CD / DVD writers uses a dye that the laser alters to create pits that are read back as digital data. CD and DVDr discs use different dyes due to the different data storage needs. The dye can be affected by bright sunlight and compared to commercial or ‘stamped’ optical media it is not as reliable.

In an exhaustive Library of Congress report, http://www.loc.gov/preservation/resources/rt/NIST_LC_OpticalDiscLongevity.pdf ‘good quality’ CDR media was expected to last ‘several decades’ and be more reliable than DVDr media:

It has been speculated that the archival quality of CD is superior to that of DVD. The basis for this lay with the physical differences in CD and DVD optical media and the maturity of the technology. In particular, the size of the bit markings in CD media not only reduces the relative effect of media or dye degradation, but also means that more stable, less sensitive dye may be used.

Out with old, in with the new

The march of technology can cost us money while making huge profits too. This of the CD reissues of old back catalogue albums, the pressure to replace vinyl collections with CDs, video tape collections with DVDs or CRT televisions with LCD or plasma screens. New technology is marketed as ‘better’ in many ways, yet it can be worse too.

Oct

2011

azimuth adjustment when you transfer and convert cassettes to cd

Cassette tapes run at a very slow speed of 1⁷⁄₈ inches per second (ips) with a very small track width of 1.59mm

Cassette decks when they left the factory or a service centre should have been aligned to a standard reference for the position of the record and play heads. Unfortunately they often weren’t all the same and over time the alignment can drift, get knocked out or manually ‘fiddled with’ by an owner.

What this means is that unless you’re playing back your tape on the machine it was originally recorded on, you may not be getting the maximum quality as the angle of the head to the recording or azimuth will not be optimal.

Without calibration tones recorded at the start of the tape (which is very unlikely on most domestic cassette tape recordings), you must set the playback azimuth manually. A few high end tape decks, namely those made by Nakamichi, either had a easily accessed Azimuth Adjust or could even automatically adjust this throughout the tape. The Nakamichi Dragon was one such tape deck and could be the best, if working well, for high quality playback.

If you want to transfer or convert a cassette to CD and adjust the azimuth yourself this is the easy way to do it:

Look at the tape path (everything the tape will move across) and if it looks brown and dirty get some isopropyl alcohol and give it a good clean with a cotton bud.
If you haven’t demagnetised your deck for a while now would be a good time to do it..
Power up your cassette deck, which hopefully works correctly and doesn’t have too much speed instability!
Pop your tape in the cassette well and start to play.
Turn your amplifier’s volume up and if you can put it in Mono.
Now, look under the tape machine’s playback or combined record and playback heads you should see a small screw or nut possibly with anti tamper paint on it.
Using an appropriate tool, turn this nut or screw a little left or right while listening to the audio.
You should hear the recording, especially if it has a lot of high frequency content such as cymbals etc. get bright and dull sounding or more technically get more in or out of phase.
Your aim is to get the most in phase or bright sounding playback.
Sounds better now?? Great, start to record using you favourite computer audio software. We like SoX for the control but there’s a huge range out there.

Oct

2011

repair of snapped DAT

We often get sent Digital Audio Tapes or DATs for transfer to .WAV computer files. As these recordings are already digital or ‘born digital’ the process should be straightforward. Our audio interface cards accept the SPDIF or AES digital audio stream from the DAT machine and record this as a WAV or BWAV file. This file can then be burnt as a CD or delivered digitally on a hard drive or removable media.

The big problems though come with the tape that these digital recordings are made on. The tape is only 3.81 mm wide and moves at a very slow 8.15 mm/sec. The tape is also very thin at 13 microns. The recording system and transport used is helical scan just like in video recording but with the very slow tape speed and small tape dimensions any defects or problems with the tape can result in many errors which may not be correctable by the error-correcting system of the DAT machine.

One problem we’re starting to see more and more are tapes that snap. The tape pictured above was a D120 which was never recommended by the DAT machine manufacturers but was still often used for its extended recording time. This tape snapped without warning a quarter of the way through the recording. There were no outward signs or potential problems just a sudden clean break on a diagonal.

To recover this tape it could have been spliced with splicing tape of the correct width like in analogue recording but there is a high risk if not done perfectly of irreparable damage to heads on the drum. Even with this type of repair some of the material would have been lost. A safer solution is to rehouse each spool in another shell. This lets you recover as much as possible from the tape, without the risk of head damage.

Whichever solution you decide, the DAT shell must be disassembled. A small crosshead screwdriver needs to be used to remove all the case screws. There are two hidden ones, accessed by sliding part of the cassette shell down:

You can now carefully lift both halves of the DAT shell apart, making a note of the tape path inside the shell. Be careful not to touch the tape with your bare skin as fingermarks and grease can cause head to tape contact problems and audio errors and dropouts.

Oct

2011

Sony PCM 7030 DAT repair

We have several of these large, wonderful machines. It’s not often we need or want to get involved in DAT machine repair as generally they are not easy to service machines and many key transport parts are becoming unavailable. The Sony 7030 DAT though has been designed with easy servicing in mind. There’s alot of room in these things and each section is clearly marked and separated into distinct boards much like Sony Broadcast video machines.

These are timecode DAT machines and were once common in video post production houses and the more well funded recording studios. The problem with some of this well built kit though is exactly that it works too well and gets left on for long periods through it’s life and this can take a toll on certain components, especially electrolytic capacitors. Heat builds up in electronic circuits, especially in switch mode power supplies that larger broadcast items often use. Capacitors have a rated life at 85°C or 105°C at several thousand hours. With hotter environments, substandard parts and long operating hours these capacitors can soon outlive their original design life.

Our 7030 DAT had started behaving oddly and at first the display would flash on and off after a short while powered on. Another machine would power up for 30 secs then just die. Before delving into the enormous service volumes it’s always worth replacing the Switch Mode Power Supplies (SMPS). These like many broadcast machines use supplies that are sometimes generic made by other companies and which can be bought at Farnell or RS. We did it the harder way and desoldered all the old capacitors in the power supply and replaced these with high quality low ESR Panasonic ones which should give us another 6000 hours of running time. So far this machine has worked perfectly although you do need good soldering and desoldering technique on these boards. A powered air desoldering station is a good idea, much, much better than a hand solder pump.

Oct

2011

Tape baking of unreleased Shoes for Industry studio master

In amongst a batch of very mouldy quarter inch master tapes we were recently asked to look at was this unreleased recording by Shoes for Industry, the Bristol band on Fried Egg Records.

Like much late 1970s and ’80s studio recordings, this was recorded on Ampex branded tape that suffers badly from binder hydrolysis or ‘sticky shed syndrome’ that must be addressed before the tape can be successfully played and digitised. This was in addition to the mould growth that was evident on the tape pack edges, and cardboard box. Storage in damp conditions and high humidity causes this type of mould and increases the breakdown of magnetic tape generally, sometimes to the point where de-lamination occurs, that is, the binder breaks away from the polyester structure of the tape. When this happens, which is luckily quite rarely, the magnetic information is damaged and mostly lost beyond repair.

Thankfully this tape, whilst it looked in poor condition was relatively straightforward to restore but time consuming. Careful hand winding, and mould cleaning is necessary as is awareness of the potential health effects of some mould spores so good ventilation and protective masks are necessary.

Sep

2011

Tape mould cleaned and removed. Rare lost masters recovered and preserved for Druidcrest Ltd

We have recently worked on probably the worst looking tapes but with some of the best sounding music recordings we’ve seen for a while! A batch of 10.5″ NAB studio masters had bad tape mould growth.

Andy Leighton, owner of Bolex Brothers and music publisher of the Rocky Horror Show, found a batch of studio masters on quarter inch tape that had been growing mould for some of them over 30 years. All of these recordings had been made at the renowned Sound and Recording Mobile studios better known as SARM, later creative home of Trevor Horn.

Among these tapes was the first ever recording made at SARM in 1972 by Richard o’Brien, writer of the Rocky Horror Show, in addition to rare tracks by artists such as Kimi and Ritz.

When the tape mould was finally cleaned from the tapes and some of them baked for binder hydrolysis the quality of the recordings was very high and testament to the high quality available from analogue recording. Even though tape can be vulnerable to physical problems, it is also robust. If these had been tape-based digital recordings, in the same condition, I doubt we’d have been able to achieve the same results.

the problems

the repairs

To replace the capstan belt:-

microswitches

is it working?

CDr and DVDr Longevity

Out with old, in with the new

Categories

Popular Tags

greatbear audio & video digitising