Hi Andres
I think that the answer to your question is yes. I have a Sandy (German) Destiny power supply working with a GGM (Great Game Machine) at the moment. All my Applied Concepts/Destiny adapters seem to have different outputs, but the jack (connector) is the same. The original GGM adaptor would probably have been 10V 830mA.
It is generally thought that the Mega-4 was never released for sale by Destiny. There are however GGMs that have been upgraded to run at 4 MHz which involves a replacement PCB in the program modules and replacement chips etc in the chess computer. The modifications are carried out by a guy from Birmingham, UK. This is his website -
http://www.great-game-machine.com/
May I ask if your Mega-4 has any features which distinguish it from a GGM, such as this one -
http://www.chesscomputeruk.com/html/...__steinit.html
All the best
Mike