Having a tidy up the other day I stumbled across a tube of 24 x LM13700N. Lucky me! Is the LM13700N a drop in replacement for the LM13600N in VCO applications? In particular I'm thinking of the VCO in Tom's cookbook, the VCO5 I think. (I'm downloading the data sheets for both at the moment but I seem to have a very slow link.) Jezz