The Class M was Edison's first major improvement on the tinfoil phonograph of 1877. After a reported 72-hour marathon session ending on the morning of June 16, 1888, Edison was photographed with his "perfected"Class M phonograph (see below). Edison liked this picture of himself as the "the Napoleon of Invention" so much that he had it copied as an oil painting which was displayed in his office for the rest of his life.

Made several years before the invention of a suitable spring-driven phonograph motor, the Class M is driven by an electric motor powered by a heavy set of Edison-Lalande Type S cells. Although most people think of the Class M as being powered by early Grenet cells, such as was pictured in the famous photograph of Edison below, those laboratory batteries were superceded by the superior Edison-Lalande cells after 1889, by the time the Class M went into the commercial market.

The governor, hidden under the bedplate in most phonographs, is prominently positioned on top of the machine, mounted vertically. Class M Phonographs were manufactured through 1890 for the North American Phonograph Company, which originally attempted to lease them as business machines for dictation. This proved to be a dismal failure, but the entertainment possibilities of the phonograph quickly caught the attention of the general public. As the North American company slowly sank into eventual bankruptcy (in 1894), Class M phonographs were finally offered for outright sale, both for business and home use. However these were extremely expensive machines ($225 when average salaries were around $40 a month), and not many were sold. Today the Class M is one of the most desirable of all antique phonographs.

A very rare stock certificate for the North American Phonograph Company, issued in 1890. The vignette pictures the Class M as well as the Bell-Tainter treadle Graphophone, which was a dismal failure. (The top works from unsold machines were recycled in 1895 into new machines like the Type K.) This certificate was signed by the founder, Jesse Lippincott, who became seriously ill later in the year and was replaced as President by Thomas Edison. Lippincott died a couple of years later, penniless.