This circuit from General Electric was found in a 1967 documentation. The SCR is of the time, as are the transistors, but equivalents can be used.
L1 is the secunday wound of a common power transformer with voltages between 6 and 12 V and...
With 12 V of power and 8 ohms in each speaker we have 1.6 W of power per channel. With a 22 V...
This circuit is from the time when seat belts were still being adopted. Obtained from a 1976...