Radiart Tone Control - The First Equalizer

Short investigation of a Radiart model JA tone control from approximately 1924-1927 . This unit would be used along with a tube amplifier, probably for sound in a cinema.
Since an empty room has different acoustics than a room full of people and there would have been much less consistency in the quality of recordings at that time it would have been useful to have a quick means to improve the sound the audience hears.

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Cool!