The scalable nature of the ZXCDSUBEV means that alternative power levels are easy to achieve. An option between BTL and SE configurations results in a 4:1 power ratio from the same supplies. Further adjustment of power is achieved by modification of the bridge power rails. Other options include protection features such as over-current sense for short circuits as well as a thermal overload detector and a DC offset detector. Additional circuits can be added to the front end of the reference designs to facilitate volume and phase control, high pass and low pass filtering.