a high common mode rejection differential amplifier wherein two serially arranged darlington amplifier stages are employed and any common mode voltage is divided between them by a resistance network . the input to the first darlington amplifier stage is coupled to a signal input resistor via an amplifier which isolates the input and presents a high impedance across this resistor . the output of the second darlington stage is transposed in scale via an amplifier stage which has in its input a biasing circuit which effects a finite biasing of the two darlington amplifier stages .