This is conducted by connecting the electrodes to a voltage amplifier.

A second wiper reads this representation of the signal, and sends it on to a voltage amplifier, where it is mixed with the original source.

Op-amps are differential voltage amplifiers with very high gain (sometimes modeled as infinite gain).

As in the case of the main Miller theorem, the second voltage is usually produced by a voltage amplifier.

Often this circuit is selected when a voltage amplifier is wanted at the output.

For example, an op amp (voltage amplifier) can be arranged to make a current amplifier instead.

For the special case of very low impedance sources, the common-base amplifier does work as a voltage amplifier, one of the examples discussed below.

For the case when the common-base circuit is used as a voltage amplifier, the circuit is shown in Figure 2.

The common-base circuit stops behaving like a voltage amplifier and behaves like a current follower, as discussed next.

Consider an ideal inverting voltage amplifier of gain with an impedance connected between its input and output nodes.