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.
Using a 741 op-amp this circuit high-pass to 10 kHz was found in the February 1995 issue of...
Found in 1965 General Electric documentation this circuit applies to a LASCR used as an optical...
Using transistors and lamps, this simple circuit was found in Popular Electronics. The circuit can...