Abstract: A digitally-controlled variable-gain amplifier is disclosed, which comprises a polarization means to transform the input signal into differential signals of positive and negative polarity; first and second gain blocks, each composed of dual-multiplying digital-to-analog converters, which multiply the polarized signals to produce positive and negative amplified signals; and a differential amplification means which receives the amplified signals, and subtracts them from each other. The resulting output signal is proportional to the input signal and yields a 3 dB improvement in signal-to-noise ratio over a single multiplying digital-to-analog converter stage. A plurality of amplification chains, each comprising a first and second gain block, may be used to amplify the differential signals for summing by the differential amplification means to provide a greater signal-to-noise ratio improvement.