Amplifier as a VCVS Modelling Block

One may consider a generic amplifer as a dependent soure. Here the functionallity of an amplifier is provided by two voltage controlled voltage sources connected by an RC LP. The VCVS have high input impedance (~10^12 Ohm) and a low output impedance (~0 Ohm). Adding an RC network between the 2 VCVSs provides an RC delay.