Abstract: A system for adapting a tracker bar operated automatic musical instrument to play electronically stored performances includes, in one embodiment family, a channel plate member having parallel channels in the upper face. First and second spaced apart holes are provided in each channel. An array of solenoid operated valves individually open and close first holes in the channels in response to energizing signals selectively applied to the solenoid coils. The second holes are oriented to interface with the tracker bar holes so that opening a given solenoid operated valves exposes the corresponding tracker bar hole to atmospheric via the corresponding channel. Left and right adjustable bracket assemblies are adapted to respectively engage the left and right pay-off spool mounting members to juxtapose and maintain the channel plate member in the operating position.

Abstract: A solenoid stack for a piano incorporating an array of striker solenoids, each of which includes an outer shell, a coil disposed within the outer shell and having an axial passage extending through its entire length, an inner shell within the coil and a slug moving axially within the inner shell in response to selective energization of the coil. The slug is provided with a passage through its length, and the passage includes an internally threaded section which a threaded push rod engages such that an upper end extends above the slug and carries a pusher tip. An adjustable stop member is provided at the bottom of the slug to limit the stroke of each individual solenoid assembly. A mounting plate includes an array of apertures for receiving the striker solenoid assemblies (in threaded, press-fit or the equivalent engagement) within the keybed such that each solenoid assembly is juxtaposed with respect to an individual keytail.

Abstract: A solenoid stack for a piano incorporating an array of striker solenoids, each of which includes an outer shell, a coil disposed within the outer shell and having an axial passage extending through its entire length, an inner shell within the coil and a slug moving axially within the inner shell in response to selective energization of the coil. The slug is provided with a passage through its length, and the passage includes an internally threaded section which a threaded push rod engages such that an upper end extends above the slug and carries a pusher tip. An adjustable stop member is provided at the bottom of the slug to limit the stroke of each individual solenoid assembly. A mounting plate includes an array of apertures for receiving the striker solenoid assemblies (in threaded, press-fit or the equivalent engagement) within the keybed such that each solenoid assembly is juxtaposed with respect to an individual keytail.