This Public Address amplifier was found in a 1947 amplifier manual. The power supply uses two transformers with two rectifier tubes.
Found in an Electronic Design from the 80's, this circuit monitors a three-phase line, activating a...
This high impedance step suggested by an English publication can operate up to 1 MHz with 1 V rms...
This powerful high-fidelity amplifier was described in an article in Radio Electronics magazine in...