Ming Da MC34AB Post Repair

The new valves have been fitted and the burnt out resistors are now in place. All of the bias controls need to be adjusted for 300mV. If you are doing this job yourself be careful because the bias pots do not all work in the same way. Some increase bias voltage in the clockwise direction whilst others decrease the bias voltage in the clockwise direction. When fitting new valves preset the bias controls to a minimum value before the new valves are fitted.