Design analysis of the K2-W Vacuum Tube Op Amp’s design and operation reveals the mad science that created a commercial revolution in 1950s and 1960s analog computing. Op amps played a critical role ...

This simple scheme is based on the circuit shown below (Figure 1) in my recent article [1]. Figure 1 Using common transistor optocoupler to achieve a tube-like sound. It is known that the main feature ...