A noise shaper truncates the widths of pulses it supplies to a pulse-width modulator whose pulse-width modulated signals control a tri-level amplifier. The amplifier is filterless and DC free. Pulses that are narrower than a predefined minimum width are eliminated by the noise shaper. Other pulses are subjected to an algorithm that includes a multitude of ranges, each range defined by a minimum pulse width characterizing a lower bound of that range and a maximum pulse width characterizing an upper bound of that range. Associated with each range is a number of clock cycles defining the modified width of a pulses whose detected width falls within that range. To ensure that delays associated with a feedback loop disposed in the amplifier are accounted for, the reference voltage of a comparator tracks an output voltage of an integrator. Both the comparator and integrator are disposed in the loop.