Apex B500 power amp’s pcb design stylish been output mje15032 and mje1503 power transistors used supply voltage symmetrical 55v … 90V from quite high dangerous circuit tests, be careful addition amphitheater to be used with fan control and protection... Electronics Projects, 500W Power Amplifier Circuit Apex B500 "audio amplifier circuits, transistor amplifier, " Date 2019/08/03