This Crest Audio MA - 540 Mixer / Amplifier comes with all you need. It includes a proper power supply, the original box, original packaging, and a user manual. It's a great choice for audio enthusiasts.

To use the Crest Audio MA - 540 Mixer / Amplifier, first, connect it to the correct power supply using the provided adapter. Place it in a well - ventilated area to prevent overheating. When using, adjust the volume and mixing controls according to your needs. Don't forget to check the connections regularly. For maintenance, keep it clean by using a soft, dry cloth to wipe it. If there are any problems, refer to the user manual or contact customer support.