Using the Blackstar FLY 3 is easy. First, connect your guitar to the 1/4' Jack Input. If you want to jam along with music, plug your MP3 player or other device into the 3.5mm MP3/Line In. To start playing, turn on the amplifier using the appropriate controls. You can adjust the Gain, OD On/Off, Volume, ISF, Delay Level, and Delay Time to get the sound you like. For silent practice or recording, use the 3.5mm EM. Out/Phones connection. When using the battery, make sure it's properly inserted and replace it when it runs out. If using DC power, use the correct adapter. Keep the amplifier clean and dry. Avoid exposing it to extreme temperatures or moisture. If you have any problems, refer to the user manual or contact customer support.