There are a few pieces of equipment involved with biasing...It has to do with measuring voltage, then doing some calculating, adjusting, then re-measuring and calculating. Biasing is not a do it yourself thing unless you have a serious background in electrical engineering.

You can easily get shocked by a tube amp just by taking the back cover off and removing a tube. The tubes (valves) hold a charge that can send you across the room, or even worst, kill you. Even after the power has been turned off and the amp has been unplugged. To properly discharge the valves, always turn the power switch off with the standby still on....or turn the standby switch on with the power switch off...