The invention relates to a power supply system and a method for providing a load (L) with electrical power from either a first or a second AC grid source (10L, 10H) that supply different first and second AC voltages, respectively. In a particular example, said grid sources may belong to the US and the European mains, respectively, and the load may be a lamp with mains compatible LEDs (Ch1-Ch4). The power supply system comprises a first and a second connector device (30L, 30H) for connecting a converter circuit (20) to the first or the second AC grid source (10L, 10H), respectively. Moreover, the second connector device (30H) comprises a transformation circuit (D1-D4) for transforming the second AC voltage such that it yields a similar output voltage of the converter circuit (20) as the first AC voltage. In a particular example, the converter circuit (20) may comprise a rectifier (D5-D8, C1, C2) with voltage doubling function, and the second connector device (30H) may comprise a rectifier (D1-D4) while the first connector device (30L) is a simple cable.