This Ashly Protea System II 4.24G digital graphic equalizer comes with a correct power supply. However, please note that the screen visibility is limited and can only be clearly seen from certain angles, and adjusting the contrast won't solve this issue.

Using this Ashly Protea System II 4.24G digital graphic equalizer is straightforward. First, connect it to the correct power supply provided. Then, you can start adjusting the audio signal according to your needs. When using, be aware that the screen might be hard to see, so you may need to find the right angle to view it. As for maintenance, keep it in a dry and clean place. Regularly check the power supply and connections to ensure everything is working properly. If you encounter any problems, you can refer to the user manual or contact customer service.