This Public Address amplifier was found in a 1947 amplifier manual. The power supply uses two transformers with two rectifier tubes.
This circuit of an old publication makes use of SCRs that admit modern equivalents. The frequency...
This PNP transistor power stage was found in the May 1969 issue of Radio Electronics magazine. The circuit...
In the figure we have an amplification stage with FET in the source follower configuration. The circuit is...