I'm not familiar with a break in process for SS amps, unlike tube amps.As mentioned... just plug it in and play. In my experience components sound different after some use than right out of the box. The degree of the change will vary from one component to another. With tube amps there are more variables that can be readily manipulated, if you choose to pursue that. And through fine-tuning you can perhaps "make" or "break" the amps performance. Least to you. With SS devices, I'm not sure if the amp bass performance will improve enough to satisfy. And if you didn't audition it in your system, there is no one to determine what aspect of the performance is related to the amp itself or interactions with parterning components/room. Listen for as long as the return policy allows. If it still isn't performing up to your standards, take it back.