A wideband video signal processing system includes a blanking interval signal conditioning circuit (14) with reduced parasitic capacitance. The circuit comprises an AC coupling capacitor (17) between the input and output of a video signal path, preferably between an input buffer amplifier (15) and an output buffer amplifier (19). A first keyed electronic switch (16) of the single pole, single throw type is coupled in series with the capacitor. A second keyed electronic switch (18) of the single pole, single throw type is coupled between the output of the capacitor and a reference voltage. The first and second switches are keyed to establi sh a fixed video signal reference value during image blanking intervals.