Abstract: Differential amplifiers and phase-splitting circuits incorporate voltage-transfer or current-transfer devices of different conductivity types that are connected in series between two different potentials. The current flowing through the two devices is responsive to input signals provided to either or both of the devices. The two devices may be of different types such as bipolar transistors, field-effect transistors, vacuum tubes, triacs and silicon controlled rectifiers. Specific implementations include amplifiers with very low input capacitance and very low second harmonic distortion, multi-state memory cells, detectors and voltage regulators.