A circuit having a dynamically adjustable common mode rejection ratio. The circuit has a high common mode rejection ratio without the need for input transformers. The circuit's ability to adjust the circuit's common mode rejection ratio is enhanced by the circuit's high input impedance. The circuit includes first and second input terminals, and output terminals. A positive leg runs from the first input terminal to the first output terminal, the positive leg including a resistor, and a negative leg runs from an input terminal to an output terminal. The digital signal processor controls a potentiometer on one of the legs to dynamically adjust the common mode rejection ratio of the circuit.