Pro-Ject Amp Box DS Mono Power Amp The Pro-Ject Amp Box DS Mono is an ultra-efficient Bi-Phase PWM (Pulse Width Modulation) stereo amplifier circuit that delivers outstanding audio performance while consuming little energy. This new cool-running circuitry exhibits not only 92% efficiency from AC to power output, but also exhibits extremely low signal spectrum distortion. The sound of the amplifier was voiced to the likes of Class A tube topology to deliver a liquid and lifelike musical presentation. Being it is micro-sized in comparison to its power output, the Amp Box DS Mono lends itself to be used in multiples for Bi and Tri-amplification applications. Gold plated 5-way binding posts suitable for banana jacks, spades, pins or bare wire ensuring a reliable and stable connection. Additionally, a trigger in/out loop is provided allowing for remote on/off from you source component. A 48V external power supply is provided that is capable of the power reserves needed for demanding musical dynamics and powerful bass response.