just a technical note:
With most amplifiers the input signal is first attenuated with the use of a potentiometer and next it is fed into an output stage with fixed amplification factor. The higher this amplification factor, the higher the noise that is contributed by the output stage.
The concept of the STEPDANCE and QUICKSTEP models is different. The input signal is not attenuated but the amplification factor of the output stage is changed with volume. This implies that at low volume settings the noise of the output stages also is much lower than on conventional designs.