Gramophone disc preservation
Gramophone discs or records have been in production for more than 100 years. Although they come in a range of materials and formats, their basic design and method of reproduction have not changed significantly. Fortunately, specialist replay equipment is still manufactured.
The Archives holds more than 52,000 vinyl, shellac and acetate discs. Acetate discs are prone to deterioration and are a copying priority. Vinyl records, such as LPs, are relatively robust and will last for many years if handled and stored correctly.
In the past, we copied our audio holdings to reel-to-reel analogue tape. This format is now obsolete so now all audio is digitised using computer-based workstations.
Preserving our gramophone discs holdings
Usually, vinyl and shellac discs are cleaned on a specialised machine that removes any foreign matter such as dust, grease or mould. Cracked or damaged discs may require gentle hand cleaning.
The audio operator must then determine the technical requirements necessary to ensure the disc is replayed as it was intended. This includes speed and stylus selection, and other variables such as turntable setup and frequency equalisation settings.
The operator monitors the sound reproduction from the disc as it is digitised using a specialised digitisation workstation. Sections of audio that skip or jump due to scratches are noted, and the digital audio file can be edited to conceal or eliminate these problems.
The audio is preserved as Broadcast Wave Format (pdf, 238kB) (BWF) files in accordance with international audio preservation standards.
Once the copying is complete, specialised audio processing software is used to quality check the preservation file for any data corruption or digital errors.
We add metadata, such as the title, content description, date and technical details, to the audio file for future reference.
The discs are then repackaged in acid free cardboard or plastic boxes and stored upright in a controlled environment. The digital file preservation copies are stored in a dedicated digital archive.