Mitchell Hudson wrote: > > I just ordered some LM3900s to finish a project and realized that I > recieved LM2900s. The package is labeled LM3900 though? Are these > interchangable? Don't worry, they're the same thing. BTW, search for the datasheet at National's website. Lots of circuit examples there. -- Edu Silva -- ES2 Audio http://audiolist.cjb.net .