Originally known as CHRS, the station operated on 1090 kHz as one of the very few daytime-only stations in Canada. Thanks to errors from BBM, CHRS once managed in the 1970s a third-place in ratings during evenings—a time when the station was not even on the air. The station added nighttime service in 1988 when it moved to 1040 kHz, While the 1090 kHz frequency remains unused, the 1040 kHz frequency is now used by CJMS in Saint-Constant, just south of Montreal.
Power Corporation, which had owned the station since the early 1990s, sold Z-104 to Corus Entertainment in 2000. Ownership of the station changed hands again in 2005 when it was transferred to Astral Media as part of an exchange of assets between Corus and Astral.
Astral Media promptly dropped the Z-104 moniker. Community radio programs were abolished and the station was integrated to the Boom FM network.