All NaimUniti systems have built-in amplifiers that are more than sufficient to drive typical hi-fi speakers. However if you decide you would like to add more power to your system to drive more demanding speakers you have the option of using the preamp output on say your NaimUniti 2 to connect it to a power amp such as the Naim NAP 200 which will deliver 70W and can drive a 2 Ohm load for long periods of time.The advantage of adding a power amp to your system will be to deliver the music with even greater levels of detail ambient information and musicality.