An apparatus for processing signals, in particular physiological measuring signals, wherein the apparatus is provided with a plurality of channels with main signal inputs (1) for receiving input signals, which input signals each comprise a specific signal component and a signal component common to all input signals, wherein each channel is provided with an impedance transforming input amplifier (3), wherein the apparatus is configured for supplying to the first input of each input amplifier (3) a respective input signal and, to the second input, an analogue reference signal which is equal for all channels, wherein the apparatus is provided with a digital signal processor (310； 410) and one or more analogue digital converters (5) for supplying the signals provided by the input amplifiers (3) to the digital signal processor (310； 410), wherein the signal processor (310； 410) is designed for converting signals received from the one or more analogue digital converters (5) at least into one or more output signals.
