The amplifier circuit board is the Yuan Jing "blue/black" TPA3116D2. Equipped with a multimeter inspected, high tolerance, Alpha 100K volume control. Solid metal, gold plated five way binding posts. Gold plated RCA connectors. A very quiet, external 12V/5A switching power supply provides power for 15 watts per channel into 8 ohms. An optional 24 volt supply for 30 watts is available.