A network element of a cable television (CATV) network, comprising an input for upstream signal transmission; one or more diplex filters (210, 212, 214) connectable to said input, the diplex filters (210, 212, 214) comprising bandpass filters for different upstream and downstream frequency bands; a plurality of components arranged to form an upstream signal path, wherein at least one of said components is an upstream amplifier (206c); means (216) for detecting a type of the diplex filter connected between said input and the upstream signal path; means (216) for determining a control signal for adjusting bias current of the upstream amplifier (206c), wherein the control signal is based on at least a type of the diplex filter; and means for adjusting the bias current of the upstream amplifier (206c) based on the control signal.