From disc to digital: MiniDisc transfer

Tens of thousands of reel-to-reel tapes and cassettes crowd the tall shelves of the Greater Manchester sound archive, held in the basement of the Manchester Central Library. In many instances these recordings may not have been listened to or touched by another human being since the day they were made, a thought that always gives one a slight thrill when picking through a distant shelf.

Our mission at Archives+ is to make heritage accessible and tangible for everyday people, as well as storing it for future generations. Recording devices may have been marketed as a means of making permanent our memories and fleeting moments, but in almost all instances the recordings we hold are degrading over time. Chemical film decays, discs corrupt, and tapes un-spool and are never again re-wound.

Boxes of MiniDiscs that make up the Tameside Oral History Project.

Even comparatively recent technology like MiniDiscs and CDs are not immune. Once the company that produced these devices no longer manufactures them, or stops supporting the software used to operate them, the only means left available to recover the sounds held within is through cannibalising existing machines or running emulators, software that recreates an older operating system on a newer interface.

The process of archiving digital copies of these recordings is an at times painstaking and laborious process, but it is also an urgent one because optical discs can be fragile, and are very susceptible to damage from light and handling. The purpose of this post is to show the process by which we take physical MiniDiscs and transfer them faithfully into backed-up digital files, preserving vanishing voices for another generation.

For our example I’ll be using the Tameside Oral History Project, an oral history project funded by the Heritage Lottery Fund in 2005. The project organised interviews with over 100 people who lived in Tameside and had emigrated from South Asia or Africa. The project was co-ordinated by Tameside Local Studies and Archives, who hold access copies of the interviews on CDs in Ashton. The original MiniDiscs live at Manchester Central Library.

The MiniDisc is a miniaturised optical disc produced by Sony in late 20th and early 21st centuries. The first stage of the transfer process is to place the MiniDisc into an MZ-RH1 Walkman, the last portable MiniDisc recorder released by Sony and the only model that allows digital transfer faster than playback. If you have one of these, hold on to it! They are currently going for around £300 on eBay but that will only go up over time.

Placing a MiniDisc into the reader.

If the reader successfully reads and recognizes the disc, the next step is to begin the process of creating a digital copy of the recording. For this, we use a pleasingly 1990s piece of Sony software called Sonic Stage. Until recently we ran v4.3 on an emulation of Windows XP but recently we’ve switched to v4.4 which runs on Windows 10. Once the disc has been accepted, it appears in the right-hand column labelled ‘Transfer’.

SonicStage, the software Archives+ uses to transfer MiniDiscs into digital files.

Sometimes in the UOSH project we are working from scratch, creating catalogues as we go. But for this collection we are lucky enough to have a pre-existing catalogue. Once the file has appeared in the transfer column, it is cross-referenced with the Tameside catalogue that lists every MiniDisc in the collection, including details of the interviewee, interviewer, a summary of the conversation, its length, date of recording, accession number and reference number.

Matching the MiniDiscs against the catalogue before transfer ensures that no mistakes are made in the labelling of the eventual sound file, and that the filename corresponds to how the physical disc is labelled. Any mistakes could jumble the collection, adding hours more work to the schedule and perhaps letting some discs slip through the cracks.

The reference document we use to check MiniDiscs against interviews.

Once satisfied that we have the right recordings, we select it and push the left-facing red arrow key, which begins the creation of the digital file. SonicStage is pre-set to deposit the completed files in a particular folder in .wav format. Once the recording has finished transferring it appears in the left-hand column labelled ‘My Library’.

Transferring the MiniDisc recording into a digital sound file.

Once we’ve checked that the transferred recording has appeared in the destination folder, it is renamed to a specific filename that matches the existing catalogue so that it can be easily found and accessed in the future. In the example we’re using, there is only one file on the disc. It is renamed ‘TOHP-82_s1_f01’, as it is the eighty-second MiniDisc in the collection, from the first track of Side 1 of the disc.

The finished audio file in its destination folder.

Once the final digital file is in its folder, we listen to sections of the recording to ensure that it has transferred correctly. If the file is corrupted, we need to figure out whether or not it was an error in the transfer process (like a digital dropout) or if there is an issue with the original disc instead. We use the spectrogram function in Wavelab Elements 9.5 to check for digital dropouts, which are momentary blips in the digital copy with no signal. When we find anything unusual like this, we’ll re-transfer the disc and compare the two resulting files to see if they are the same.

We also listen to make note of the quality of the recording, for example if the audio is fuzzy or whines, whether people are talking in the background and, most importantly, to ensure that the person being interviewed is the same person our paper files say they are!

We note this down in a tracking sheet, which logs which discs have been transferred, catalogued, checked and ingested and which are still to be processed. Finally, a copy of the checked-over sound file is also placed into the ‘Ingest’ folder with the affix ‘AP_’ added to its name to show it is an Archives+ file for ingest to the British Library.

Listening to the finished audio file and logging its details on the tracking sheet.

Sometimes when a MiniDisc is placed into the reader it will have more than one file on it, as seen here. This occurs when during the original recording session the recorder itself was turned on and off, usually due to an interruption occurring during the interview. In these cases, we make a note of the lengths of each of the tracks to ensure they add up to the total running length listed in our paper folder. It’s also important that we note the order the tracks are in, so that when they are named they are given the right track number. We then go through the same process as before, creating digital copies, renaming them and placing them in their own folder, in this case ‘TOHP-81’.

Transferring and creating digital files from a disc with more than one track.

Most of the time there are just a handful of tracks but the most we’ve ever found on a disc was 147! We keep all of the tracks locally, and create a longer, stitched-together track per disc. This is the UOSH preservation copy which will be archived by the British Library. Keeping the individual tracks gives us a backup just in case the process of stitching goes wrong.

The folder for the Tameside Oral History Project is therefore split into two sub-folders, ‘Raw’ and ‘Ingest’. Inside ‘Raw’ are further sub-folders, one each for the contents of each individual MiniDisc. The two tracks in this instance are placed in a folder named ‘TOHP-82’.What we then have to do is to join the files together to make a single audio file. This is done with a piece of software called Shuangs Audio Joiner. The files to be joined are selected and placed into the joiner, the ‘join’ button is pressed and the audio format for the final file is selected, in this instance the .wav format.

The file destination, the ‘Ingest’ folder, is selected, and the audio files are stitched together. We then check that the process has been completed and listen to bits of the new audio file to ensure each track is in the right order. The ‘Raw’ folder preserves the digitally transferred files in their original states, while the ‘Ingest’ folder houses only completed files, ready for delivery to their final destination at the British Library.

Using Shuangs Audio Joiner to stitch several tracks into a single audio file.

I hope this post helps illuminate the work we do to bring our sound heritage to life. I’ve been personally working on the TOHP collection once a week since last November, and I have now finished all 141 transfers. To an outsider it may seem a somewhat byzantine process, but there is a certain satisfaction one gets from taking what might have otherwise just been sitting on a shelf and rendering it in digital form, ready to be listened to more easily and forever.

You can read my blog English Voices – Asian Stories about the content of the interviews. You can read the catalogue at the British Library’s Sound and Moving Image catalogue (search for TOHP). We hope to publish some of the interviews in full at the British Library’s website as part of Unlocking Our Sound Heritage, and the collection will be available at Tameside Local Studies and Archives when it re-opens following lockdown.

Isaac Hart, Volunteer, Unlocking Our Sound Heritage North West Hub, based in Archives+, Manchester Central Library.

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