Audio Digitisation QC Quiz #2

Question 2:

‘Sticky shed’ syndrome is a common name for a condition whereby magnetic tape deteriorates by absorbing moisture (hydrolysis) and the binder that holds the composition of the tape together starts to ‘shed’ and break down. What does a tape with sticky shed sound like when played?
The audio recording will sound more muffled and there may be an audible squeaking from the tape playing on the machine.
The audio will sound wobbly like a terrible impression of Belinda Carlisle.
Nope!
There will be more of a heavy bass sound.

EXPLANATION:

Video showing the sound an open reel player can make playing a sticky tape…
The above audio was digitised from a tape with sticky shed.
This is the same recording after the heads have been cleaned.

One of the most important parts of the digitisation of analogue recordings is to clean and maintain your playback equipment. Tapes which are sticky leave lots of gunk that builds up over the rollers, tape lifts, and heads. The playback head needs to be spotless to have the best opportunity to capture the full signal. Archival best practice means we’re trying to do everything we can to get the best signal on playback, so we clean our machines between every reel.

In the worst cases we even bake the tape overnight at 50°C in a conservation (not domestic!) oven. This drys out the moisture to give an opportunity for improved playback the next day. The British Library have many years of experience baking tapes and for this project provided all the UOSH hubs with a tried and tested food dehydrator. 12 hours on the mushroom setting works wonders!

Food dehydrator used to ‘bake’ sticky tapes overnight to remove moisture.

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