The recording process

The recordings were made in September 1928. The audio technology of the time was very different from today, and the effort put into making these recordings is astonishing. Columbia Graphophone Company (which then became Columbia Records), one of the first gramophone companies in the UK, was behind the recording process. The location of this “bubble”, 8-11 Great Castle street, is where their headquarters were at the time. The recording process. First the medium used was a wax disc, engraved by a needle. The wax disc would then be metallized to create a “master” with which mass production of shellac discs would be done. Shellac is a resin (secreted by a bug) that predates the more widespread and recent polyvinyl chloride used for vinyl records. The equipment needed for the engraving would take up an entire room, and was composed of: electric batteries to supply the power, ovens to soften the wax in preparation of the engraving, and vacuum tube amplifiers to amplify the microphone signal to the level necessary to drive the needle motor. The microphone would be attached with a very long cable running from the equipment room to the street, often hanging from windows. The exact locations for the recordings were thus subject to finding an available space for the installation of the recording equipment. Since only one microphone was used, the recordings are monophonic.