15 years ago the Power Electronics Group at PSI, Switzerland developed power supplies (PS) for the magnets of the Swiss Light Source (SLS). These PS are based on switched mode converters with fully digital control. During the 12 years of operation of the SLS they have shown a very good reliability but also revealed some potential for improvement: After several years of operation the many fans installed started to fail more frequently and the same was observed for “off-the-shelf” AC/DC converters for the DC link. For the new SwissFEL, which shall be in service by 2016, approx. 670 PS rated at 10 A and 20 PS rated at 50 A will be necessary. As for any accelerator application high stability and reliability of the magnet PS are essential for high beam quality and availability. The development of the SwissFEL PS aims to raise the already good reliability by omitting as many fans as possible and adding redundancy for the AC/DC converters. Presently, a prototype rack with 21 10 A PS is available and the mass production has started. The presented paper describes the PS concept and test results of the prototype regarding stability and efficiency are given.