Kramer Electronics 904 904 is a high performance power amplifier for balanced stereo audio signals. It will amplify a balanced stereo audio signal from a preamp and output 75 watts per channel delivered into a 4 ohm load. Digital Class T Technology - S. Control - Volume, mute. Multi-color LED Stereo Level Indicators on the Front Panel. Built-in Short Circuit Protection. Worldwide Power Supply - 110-220V AC. Standard 19inch Rack Mount Size - 1RU