In 1888, his apprenticeship was completed and Johnson became a machinist at the recently established Scull Machine Shop across the Delaware River in Camden, New Jersey.

John Warwick Scull had graduated from Lehigh University the previous year with a degree in mechanical engineering,[5] and his father Andrew financed the purchase of the building at 108 N. Front Street in Camden for his son to set up shop in.

While cylinder phonographs had been successfully equipped with clockwork motors, the disc playing Gramophone presented a number of design challenges in this regard.

Johnson also spent a winter in Philadelphia collaborating on various Gramophone refinements with Alfred C. Clark; the most significant of these was a vastly improved soundbox.

Johnson had long been dissatisfied with the raucous, scratchy sound of Berliner's discs and believed a better recording and mastering process could be developed.

From this master, stampers could easily be made for mass production of records—a definite advantage over the difficult-to-duplicate wax cylinders of the Edison Phonograph.

[citation needed] Examining the Berliner discs under a microscope, Johnson recognized that the acid etched process was creating random jagged grooves in the records, which were excessively scratchy and noisy when played.

[citation needed] Johnson was successful in developing an improved process of recording, but mass production still proved challenging.

Johnson had obstinately refused to acknowledge the serious competition the new medium of radio posed to the phonograph record industry; this was one of several factors which led the vast Victor Talking Machine Company to the brink of bankruptcy in 1925.

After the company successfully rebounded from this debacle, Johnson, after years of turning down prospective buyers, began to seriously consider selling Victor and retiring from the phonograph business.

He donated large sums of his vast wealth to various charities and established the Johnson Foundation for Research in Medical Physics at the University of Pennsylvania in 1929.

Having been in failing health for several years, Johnson died at the age of 78 on November 14, 1945, in Breidenhart, his home at Moorestown Township, New Jersey, after suffering a stroke days earlier.

[10] On February 26, 1985, Johnson posthumously received the 1984 Grammy Trustee Award, given to persons who made a significant contribution in the field of recording.