Each amplifier has its own built-in power supply that produces direct current to power the amplifier module. To isolate the power supply current from the common signal cable, there are couplers (A/S) in the structure. An amplification module may contain several (at least two) amplification stages. For the input stage, the most critical indicator is the signal-to-noise ratio, and for the output stage, the indicators of nonlinear distortion. The step structure of the amplifier module is typical for mainline amplifiers. The amplifying device may include several equalizers installed both at the input or output of the amplifier, and between the stages of the amplifying module (interstage equalizer). The purpose of the equalizer is to compensate for the linear distortion of the transmission spectrum resulting from the signal passing through the coaxial cable and passive devices, i.e., to reduce the unevenness of the frequency response of the transmission path. In this scheme, the signal passes through the equalizer before amplification.