Normally, if you want to control the gain of an amplifier, you’ll use a variable resistor. You know, like a volume control. But what if you want to control the amplifier’s gain with a voltage?

It used to be a rite of passage to be able to do the math necessary to design various bipolar transistor amplifier ...

A question that arises frequently in audio and signal processing applications is this: How can I control gain on dual channel (e.g., stereo) inputs simultaneously with only a single knob? Of course, ...

Back in the '60s, there was an intriguing circuit article titled "Starved-Circuit Amplifier" published in Popular Electronics magazine. It used a sharp cut-off pentode with a 3-MO load resistor and ...