There are some important updates to this project, as shown below. Recent testing has shown that with the new ON Semi transistors it is possible to obtain a lot more power than previously. The original design was very conservative, and was initially intended to use 2SA1492 and 2SC3856 transistors (rated at 130W) - with 200W (or 230W) devices, some of the original comments and warnings have been amended to suit.
Rangkaian 500Watt Power Amplifier Skema Rangkaian 500Watt Power Amplifier
Note:
* This amplifier is not trivial, despite its small size and apparent simplicity. The total DC is over 110V (or as much as 140V DC!), and can kill you.
* The power dissipated is such that great care is needed with transistor mounting.
* The single board P68 is capable of full power duty into 4 Ohm loads, but only at the lower supply voltage.
* For operation at the higher supply voltage, you must use the dual board version.
* There is NO SHORT CIRCUIT PROTECTION. The amp is designed to be used within a subwoofer or other speaker enclosure, so this has not been included. A short on the output will destroy the amplifier.