A digital front-end architecture for television receivers with sigma-delta ADC input. An input digital signal is fed to the architecture and the gain is controlled by a gain stage. In the first method, the gain stage is controlled by a first AGC. Here, the gain is increased if the first threshold value is larger than the magnitude of a complex phase-locked loop (CPLL) output, and the gain is decreased if the first threshold value is lower than the magnitude of the CPLL output. In the second method, the gain is controlled through a second AGC. The gain is controlled by increasing the gain if the second threshold value is larger than a line peak of the moving average filter output, and the gain is decreased if the second threshold value is lower than the peak. The second threshold value and the peak are compared in a peak search block.