The QUICKSTEP is a technically very sophisticated portable amplifier. This amp was designed to provide the best possible portable sound with a minimum of compromises towards size and current consumption.
The amp not only uses the concept of active balanced ground but also has a discrete volume control (32 positions, two gain settings). This volume control is not a standard industrial solution but uses a concept in which the position of an analog potentiometer is measured using a low-power ADC and in which the output of this ADC is used to control electronic switches that set the volume level. The result is a very clean and detailed sound without any channel imbalances.
The 3.5 mm sockets, mechanically often the weakest point of a portable amplifier, are heavy duty. Also much care is taken that the amp does not react to RF-signals at the input, thus making it immune to RF-pollution caused by mobile headphones.