The recording engineer Hazel Yarwood, who has died aged 89, worked at Abbey Road studios in St John's Wood, north London, from 1947 to 1985. A technical and sonic pioneer, she could be relied upon to make any new system work and was the first engineer to make a diamond cutting stylus work on lacquer discs. The normal type of stylus was made of sapphire and would last 20-30 hours, but Hazel managed to make the diamond stylus last for more than 1,500 hours.
She also cut the first digital recordings made on EMI's own equipment – Debussy's Images and Prélude à l'Après-midi d'un Faune, conducted by André Previn, in 1979 – and was the first engineer to use the new Neumann Digital Metal Mastering system, early in 1984.
Hazel was born in Blyth, Northumberland, and went to boarding school in north Wales. Her interest in music, dancing and dramatics led her to join the Pilgrim Players, with whom she performed all over the country during the second world war. She joined Ensa to entertain the troops and after rehearsing Pink String and Sealing Wax at Drury Lane, she toured with Ensa in Belgium, France, the Netherlands, Germany and the Middle East.
I joined Abbey Road studios in 1972 as a junior technician and one of my main tasks was helping to look after the six cutting rooms. As a rather green young man, coming into the strange world of recording, to have a friendly, welcoming face like Hazel's was a great help. She had the attitude that coming to work required true professionalism but that didn't mean that you couldn't have fun as well. She always had her "whackers" ready at hand to punish those who were too slow or got it wrong. These were made up of the plastic spacing strips that went round each master lacquer.
Hazel was steady and careful in her work, resulting in excellent classical LP cuts, whose sound quality was praised within the industry and has been hard to match.
Hazel is survived by her sister, Cicely, and her niece, Susan.