The Amp Box DS2 Mono from Pro-Ject Audio belongs to the family of solid monophonic power amplifiers. The power amplifier is a device that accepts the signal from the respective source (cd/dvd player, turntable, radio, etc.), after it has passed through a pre-amplifier. It then amplifies it properly and transfers it to the speakers for playback. For this reason, power amplifiers usually only have the on/off button. In this case, it operates with transistors or otherwise solid state. Since it is monophonic, you need to combine two to have stereo sound. The power is 205W/4Ω or 120W/8Ω.