Best known the innovative in-house producer at Factory Records between 1978 and 1981, Martin Hannett was personally responsible for the 'Factory sound' of that era. Hannett produced nearly every band on the roster at the time: Joy Division, New Order, A Certain Ratio, Section 25, Durutti Column and OMD. Following internal financial conflicts Hannett left Factory in 1982, but would later return to produce Happy Mondays. Aside from Factory artists Hannett produced many other bands, including Buzzcocks, Magazine, U2 and John Cooper Clarke. After years of drug related problems, Hannett died in 1991 of heart failure. That same year Factory issued a compilation of Hannett's finest production moments, since then there have been two further Hannett compilations.