Inside was a simple servo, with a differential amplifier comparing the feedback via a potentiometer from the mechanism with the amplified input. The recorders dated from the early 1960s ...

With one regular input and one inverting input (+ becomes -, - becomes +), it multiplies the difference by a constant factor. Differential amplifiers are used in myriad applications, including ...

Here comes a new compact power amplifier that isn’t made in China: Pro-Ject Audio Systems’ Amp Box RS2 is made in Europe; it connects a tube-buffered input stage to an all-discrete Class A/B output ...

It is possible to upgrade the amplifier from 500 kHz to 5 MHz later ... The front panel of the MFLI has one differential voltage input, one current signal input, two auxiliary inputs, and one ...