How Does a Victrola Portable Crank Phonograph Work?

The Victrola was an acoustic predecessor of the electric phonograph.

The Victrola was a crank-powered phonograph that produced sound solely through acoustic means. The Camden, NJ-based Victor Talking Machine Company, founded in 1901, manufactured Victrolas.

Drive Mechanism

Rotating the hand crank of a Victrola portable crank phonograph loads an internal spring with potential energy. As the spring tension releases, it powers a motor that drives the turntable. The drive mechanism uses a simple governor to ensure that the turntable rotates at a constant speed of 78 RPM, or revolutions per minute, significantly faster than the later standards of 33 1/3 RPM for long-playing records and 45 RPM for singles.

Tone Arm

The tone arm consists of a stylus, or phonograph needle, connected to a hollow tube containing a flexible diaphragm. As the turntable rotates, the stylus tracks through a lateral-cut groove in the record. The variations in the groove vibrate the stylus, and a lever connected to the stylus transfers those vibrations to the diaphragm.

Soundbox

Early Victrola soundbox designs used the now-iconic external horn to magnify vibrations from the diaphragm into audible sound. Eventually, Victor replaced the external horn with an internal horn hidden beneath the turntable. This revised, compact design was easier to store and allowed users to adjust the output volume by opening or closing doors in front of the horn's mouth.

References

• The Victor-Victrola Page: Basics Of The Acoustic Phonograph
• State Of Delaware: Johnson Victrola Museum

Resources

• Read this Article in Spanish
• Widener University: Old Time Music: Victrola Pictures