What Mains Voltage do I set my vintage amp on ?
In the “old days” UK mains voltage was 240 volts AC and Ireland plus mainland Europe was 220 volts AC. With the tolerances back in those old days UK mains voltage could be as high as 264 volts AC, so running an amp that was set for 220 volts AC in the UK could mean that the amp was being run at 20% over voltage. That means your valves have a heater voltage that is
