We have recently completed a job for Quarry Faces, the Mendip Hills Community Heritage Project which has been funded by the Heritage Lottery Fund. Quarry Faces gave us 20 u-matic video tapes that were commissioned for a corporate video in the 1980s.

The Quarry Faces project aims to tell the industry’s story, produce teaching materials for both educational purposes and general interest, and create an archive to preserve images and memories of quarrying over time.

This video we digitised was shot by Coloroll Films of Kilmarnock in 1985, and was delivered to us on u-matic tape. It features a giant walking crusher at Foster Yeoman’s Merehead Quarry (Torr Works).

Walking Crusher at Foster Yeoman Ltd’s Torr Works in 1985 from Quarry Faces on Vimeo.

The video tapes we were sent were high band recordings, rather low band and of very good quality. One AMPEX U-matic tape however was problematic as the tape shell / mechanism had degraded over time and needed careful hand rewinding and reshelling in a known good and newer cassette shell.

When faced with damaged tape, often people automatically assume it needs dehydrating, a process that forces the moisture out of the tape through stable, precise, low temperature baking. However if this is not what is wrong with the tape, dehydrating or ‘baking‘ as it is more commonly called, may in fact damage the tape. If you bake acetate tape that was commonly used in the 1950s and 1960s for example, it would be destroy it.

Ampex filed for a patent for the correct temperature to recover Ampex tapes. The patent referred to “a typical temperature used is 54′C. and a typical effective time is 16 hours”.

The simple truth is, there is no all encompassing answer to know what happens to tape when it degrades, or when the cassette shell mechanism malfunctions, and each tape that is sent to us is of course individual. Digitisation and the art of restoring old tape is a relatively new area, and no one has yet made a machine that is able to precisely diagnose what is wrong with each individual tape when problems occur. Is the tape suffering from sticky shed syndrome or binder hydrolysis, or is it ‘vinegar syndrome’, a condition which afflicts acetate tape? Only through careful diagnostic work, which at Great Bear includes using our range of in-house test tapes, can the correct remedy be found.

We’ve been a bit quiet since last year on our blog here primarily because we have been processing 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 1950′s up the early 90′s, 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 1980′s onwards.
• Some glue used in spices from the 1980′s 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 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.

We’ve been honored recently to have won a large contract to help in the digital migration of an extensive educational video archive by the transfer from U-matic archive copies to uncompressed video files.

While the archive had been stored in an suitable environment and rarely if at all played, they had not survived well. The Sony branded tapes from the 1970′s and 1980′s all exhibited binder hydrolysis or sticky shed syndrome. We were still able to get good transfers though using our range of umatic machines, particularly the Sony BVU-950P and For-A Time Base Corrector.