An apparatus for processing signals, in particular physiological measuring signals, is provided with a number of channels with main signal inputs for receiving input signals. Each of the input signals has a specific signal component and a signal component common to all input signals. Each channel is provided with an impedance transforming input amplifier. The apparatus supplies a respective input signal to the first input of each input amplifier and an analog reference signal, which is equal for all channels, to the second input. The apparatus includes a digital signal processor and one or more analog-digital converters for supplying the signals provided by the input amplifiers to the digital signal processor. The signal processor converts signals received from the one or more analog-digital converters at least into one or more output signals.
