Output Voltage:0-130V or 0-260V with internal output transformer0-22.5 rms. into primary of external output transformerFrequency Response: 40Hz to 20KHz with internal output transformer20KHz to 200KHz with external output transformers (at additional cost) Regulation: 1 % line and load on transformer primary side.Distortion: 0.5% mid bandInput Requirement: 0-2V rms. into 600 ohmsShort Circuit Protection: Automatic reset thermostatOutput Meter: 0-30V analog volts meter on primary of output transformerOptional Output Transformer: up to 10, 000V rms. and up to 200A availableInput Power: 120V or 230V 5060 Hz for model 250S-HF. 350S-HF and 500S-HF208V or 190, 225, 240, 380, or 450V 50Hz60Hz for model 1500S-HF