As a result, op amps are usually connected to a negative feedback, which is evident in an op-amp inverting circuit (Fig. 2). An inverting op amp features an output voltage that changes in the ...

Philbrick Researches’ K2-W is a very-high-gain op-amp design using only two vacuum tubes. There’s a sweet book on Op Amps that’s available for free download from Analog Devices.

Cascading these two ratios (both controlled by the R2 pot), results in a total IN-to-OUT gain product of: I/O gain = (2ccw/ (1 + 2ccw)) (8.06/2cw + 1) Figure 2 shows the plot of the pseudo-logarithmic ...