This small 1W turntable amplifier was found in the 1975 RCA tube manual. It is a commercial circuit at the time.
Suggested by Siliconix in documentation from the 90s, this amplifier has its gain digitally...
January 2017 - Pulse Electronics ER11 transformers with high insulation can be obtained from...
This circuit is from an American 80's documentation. The circuit indicates when the voltage of a 9 V...