This circuit with output powers of 2 to 3 W depending on the power supply was found in the magazine Radio Electronics of April 1990. The speakers are 8-ohm.
This filter, from an audio publication from 1977, passes the frequency range corresponding to the...
In the figure we have three voltage doubler configurations that can be used in high and low...
This circuit was found in Motorola documentation from 1966. The lamps are according to power and...