Apparatus, systems, and/or methods are disclosed relating to a welding-type power supply with a pre-regulator circuit configured to provide a pre-regulated direct current (DC) bus at two or more voltage levels, responsive to various operating conditions. In some examples, the pre-regulator circuit may be configured to provide a pre-regulated DC bus voltage at one voltage level for certain input line voltages, weld processes, and/or target weld output levels, and at another voltage level for other input line voltages, weld processes, and/or target weld output levels. In some examples, the pre-regulator circuit may be configured to provide a pre-regulated DC bus voltage for certain input line voltages, weld processes, and/or target weld output levels and an unregulated DC bus voltage at other input line voltages, weld processes, and/or target weld output levels. In some examples, the pre-regulator circuit may be configured to provide a pre-regulated DC bus at a service voltage in response to detecting a service mode of operation, and/or at an idle voltage in response to detecting an idle mode of operation.