This is a simple tubed mixer from the 50's. The circuit does not include the power supply and has 3 inputs with independent controls. The tubes are double and the inputs are high impedance.
This circuit is designed to trigger a xenon lamp from a switch. The circuit was found in the May...
This circuit can measure voltages from 0 to 10 V with a very high input resistance. The circuit is...
The circuit next to a French publication from the 1980s serves as a reference for fluctuating...