Abstract: The amplifier (10) includes: an output (14) for feeding a load (16); a voltage generator (18) presenting very high linearity and very low output impedance; a current source (40) having its output connected to the output of the voltage generator (18) at a coupling point (SCP) connected to the output (14), the output of the voltage generator (18) being connected directly to the coupling point (SCP) without any resistive element being interposed between them; and a control stage (42) for controlling the current source (40) from the current (i1) delivered by the voltage generator (18). The control stage (42) for controlling the current source (40) includes current measurement elements (43) for measuring the current (i1) delivered by the voltage generator (18), which elements are disposed solely upstream from the output (14) for feeding the load (16).