First, thanks to analogguru for this schematic: http://analogguru.an.ohost.de/193/schem ... iplier.gif
I did it and it works well until it is open (no connections/supply to main circuit)
As I use it to powering a IC (TL072) for dual supply the charge pump vanish the effect....
So I'm wondering it is designed for Transistor use or there is any special trick I can take for let it working with ant Op-Amp. ??