The company was a descendant of Brandes, a Canadian company founded in Toronto in 1908. Brandes became part of AT&T in 1922 and a British subsidiary Brandes Ltd. was established in Slough, in 1924, to manufacture headphones. The company rapidly expanded producing a range of loudspeakers and in 1928 moved to a former silk mill at Foots Cray. The company was renamed Kolster-Brandes Ltd. after the American parent company merged with the Kolster Radio Corporation. In 1930 the company supplied 40,000 of its Masterpiece two-valve, bakelite cabinet radios to the Godfrey Phillips tobacco company, who gave them away to customers in exchange for cigarette coupons. K-B also began a long association with Cunard after they won a contract to provide communications equipment for the RMS Queen Mary ocean liner. In 1938 K-B became part of ITT's British subsidiary STC. The Foots Cray site was also shared by Brimar, another STC company founded in 1933 to manufacture American pattern valves for the British market.
KB made a large amount of radios and radiograms, a few models of which include the 285, 422 Cavalcade, 666 and CG20, to name a few.
The company also made a popular selection of record players which include the Playtime, Gaytime, Dancetime, Tunetime and Rhythm, the latter two of which are valve operated.
KB made the "Queen" tabletop television set, which was one of the first affordable mass-produced television sets. The set used 20 valves and operated at 12 kV.