3M introduced the 1-inch eight-track version of their model M-23 recorder in 1966, probably the first mass-produced machine of this format. It remained in production until 1970 and was used by many top studios worldwide including Abbey Road Studios in London. Both Pete Townshend and John Lennon had 3M 8-track machines in their home project studios c. 1969–1970. Ampex began mass production of their competing 1-inch eight-track MM1000 in 1967. One of the first 8-track machines in Los Angeles was built by Scully Recording Instruments of Bridgeport, Connecticut and installed at American Recorders in late 1967. The debut album by Steppenwolf was recorded there and was released in January 1968.