Transmission system control circuit including comparator apparatus

The invention relates to a transmission system comprising a control circuit which circuit includes a comparator (18, 19, 20; 25 to 29; 46; 50 to 52, 57 to 60) for comparing a first input signal and a second input signal. For reducing the low-frequency phase error, the comparator (18, 19, 20; 25 to 29; 46; 50 to 52, 57 to 60) is provided for changing the state of a first comparing signal derived from the first input signal and/or the state of a second comparing signal derived from the second input signal, or the state of the output signal resulting from a combination of the two comparing signals at instants denoted by an auxiliary signal whose frequency deviates from the frequency of the signal to be changed.