A stream of high-speed bipolar signals (18) (19) transmitted along standard twisted pair (13) telephone wiring are detected by a circuit (10) that includes a pair of differential amplifiers (20) (21) each having a signal input (11) (12) connected directly to one conductor (14) (15) of the twisted pair (13) and a reference input (22) (23) connected through a peak voltage detector (29) to the opposite conductor (14) (15). The amplifiers (20) (21) function as an input signal comparator which generates a corresponding bit stream of logical ones in response to the bipolar signals that exceed 50% of the average peak voltage input. A threshold bias voltage corresponding to positive going signals on each conductor (14) (15) is generated by the detector (29) and charges separate capacitors (37) (39) that connect each reference input (22) (23) to its conductor (14) (15). The bias voltage and bipolar signals input to each amplifier (20) (21) are algebraically summed which doubles the differential input signal and results in an increased signal to noise ratio of about six decibels.