Ken... go to the Powertran Transcendant 2000 shematics. Seek and ye shall find. You'll need to play with the values a bit but the basics are there. Regards, Tony Allgood Penrith, Cumbria, England Oakley Sound Systems www.oakleysound.co.uk Modular Synthesisers www.oakleysound.co.uk/projects.htm