qnli question: Who released 7" microgrooved records in the 1950s? sentence: One of the first attempts at this was in the 1950s, when inventor Ewing Dunbar Nunn founded the label Audiophile Records, which released, in addition to standard 33 1/3 rpm LPs, 78 rpm-mastered albums that were microgroove and pressed on vinyl (as opposed to traditional 78s, with their shellac composition and wider 3-mil sized grooves).