Hammond Solovox Keyboard and Tone Cabinet (Model L) 1948

This is a Hammond Solovox Keyboard and Tone Cabinet Model L Series A, made in 1948. This attaches to a piano as a second keyboard to create an organ sound, and it can act as a subwoofer or add effects to your sound.

Here is an excerpt from 120years.net that describes the keyboard in greater detail:

"The Solovox was designed by engineers Alan Young, John Hanert, Laurens Hammond (speaker cabinet) and George Stephens of the Hammond Organ Co and manufactured in the United States between 1940 and 1948. The Hammond Solovox was a monophonic ‘keyboard attachment’ instrument intended to accompany the piano with organ type lead voices – similar to the Clavioline and Tuttivox. The three octave short keyed keyboard was stored on a sliding mounting under the piano keyboard with a knee operated volume control. The instrument was connected to an electronic sound generation box, amplifier and speaker housing by three thick cables and derived it’s sound from a single LC oscillator with  a one octave frequency range – the signal from which was then passed through a series of 5 frequency dividers to create a further two octaves."