It has easy bias.To use the easy bias you will need a small slotted(flat blade) screwdriver I usually start by turning the screws counter clockwise a dozen times or so before turning on the amp.Then I turn the amp on and let it warm up for 10 minutes or so.After it warms up turn each of the screws until the little red light comes on solid and that's it you are ready to go.If the tubes are new check after the first hour by turning the screws counter clockwise until the light flickers and then back until light is solid again.New tubes should be checked every so often until the settle in but should hold a steady bias after that
