Fire-Lite ACCAAM25 Replacement board.

The optional ACC-AAM25 Audio Amplifier Module is identical to the
module provided with the factory standard panel configuration. It can
be used to provide a second 25 watt speaker circuit, increasing the
total speaker power to 50 watts, or it can be used as a backup amplifier. Connector J1 on the Audio Amplifier Module plugs into connector
P3 located at the bottom center of the main circuit board.