> Pin 13 (substrate) is tied to -V. Be careful with this. The collector to substrate breakdown voltage is only 20V for a CA3046. This is the worst case value, but its best not to go too near. Regards, Tony Allgood Penrith, Cumbria, England Oakley Sound Systems www.oakleysound.co.uk Modular Synthesisers www.oakleysound.co.uk/projects.htm