You need a wall outlet with plenty amperage.
- For use on 110 volts: 10 amps or more
- For use on 220 volts: 16 amps
The reason for the 16 amp requirement for 220 volts is that the power supply, regardless of which type you choose to use, will draw a lot of power on startup. We have had a few unfortunate occasions where the circuit breaker has tripped when the both the PA3/SPA4 and the power supply were switched on simultaneously. When the breaked tripped it lead to a spike and shorted the STW mosfet, and in turn damaged the power supply. This is an unfortunate and unlucky chain of events, but still a potential problem. It is a higher risk for 220 volt users due to the significantly higher amperage. So for 220 voltage use, it is especially important to have a 16 amp circuit available, to avoid the circuit breaker going off when switching on the power supply.
To avoid this potential problem, Ralph Hartwell at Spektrotek recommends that the PA3/SPA4 is switched on a few seconds before the power supply. This will make sure the PA3 is ready, and minimise the risk of damage in case the breaker trips when the power supply is switched on.