PSI researchers are developing a technique that uses the special synchrotron X-ray light from the Swiss Light Source SLS to non-destructively digitise recordings from high-value historic audio tapes – including treasures from the Montreux Jazz Festival archive, such as a rare recording of the King of the Blues, B.B. King.
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Reading the magnetic states
Audio tapes store information in a layer of tiny magnetic particles – like little compass needles pointing either north or south. When the tape is recorded, their magnetic orientation is changed – the tape becomes magnetised, and the audio information is now physically stored in the orientation pattern. To play back this pattern, the tape is moved past a play head. As the magnetic field constantly changes through the pattern, a voltage is induced in the play head and an electrical signal is generated. This signal is amplified and converted into an acoustic signal.With his X-ray method, Gliga does not rely on the magnetic field, but on the individual compass needles that generate this field. “The magnetisation states of these tiny particles, whose size is smaller than a tenth of the diameter of a human hair, can be read out almost individually using the X-ray light of the SLS and converted into a high-quality audio signal.”
Full article: https://www.eurekalert.org/news-releases/1040556
Forschende des PSI entwickeln eine Methode, um mit dem speziellen Röntgenlicht der Synchrotron Lichtquelle Schweiz SLS Aufnahmen auf hochwertigen historischen Tonbändern zerstörungsfrei zu digitalisieren – darunter auch Schätze aus dem Archiv des Montreux Jazzfestivals – so zum Beispiel eine seltene Aufnahme des «King of the Blues», B.B. King.