Processes and apparatus for the transformation and transmssion of electric currents or sounds
US1856910A
Process and device for transformation of electric currents
US1885994A
Talking machine
GB340976A
Improvements relating to gramophone and like sound records
GB332947A
Improvements relating to the production of sound records particularly for use with gramophones or the like
US1780378A
Electric pick-up for gramophone or other sound records
GB328039A
Improvements relating to sound-reproducing or recording machines
GB311366A
Improvements in electromagnetic pick-ups for disc records or the like
US1894029A
Device for the transformation of electric currents
GB303741A
Improvements in thermionic valve circuits
US1778211A
Phonograph pick-up apparatus
US1896743A
Amplifier
GB301229A
Improvements in installations comprising an amplifier or wireless telegraph apparatus and any source of vibrated or modulated electric current such as an electric phonograph disc reproducer
GB300490A
Improvements in apparatus for use in the electric reproduction of sound from disc orequivalent sound records
GB301227A
Improvements relating to apparatus for electrically reproducing from phonograph discs
