Green’s Dictionary of Slang

a large, portable cassette recorder/player.

1989		C. Hiaasen Skin Tight 61: The dental-drill rap of Run-D.M.C. from a distant quadrophonic blaster.
1993		J. Mowry Six Out Seven (1994) 22: Whatever was stashed in the clubhouse for eating and drinking had to be replaced by whatever dude whose belly it filled. This also applied to batteries for their blaster.
1999		(con. 1979–80) A. Wheatle Brixton Rock (2004) 102: Kiss me granny duty toenail [...] you actually t’ief the blaster.
2001		(con. 1981) A. Wheatle East of Acre Lane 154: Burning Spear’s ‘Jordan River’ preached from the blaster.