The OpenEEG project is about making plans and software for do-it-yourself EEG devices available for free (as in GPL). It is aimed toward amateurs who would like to experiment with EEG.
I found the amplifier designs extremely good as a learning material.
– ananth
Amplifier schematic [55kb] (aka analogue board; contains two amplifiers) and digital board schematic [48kb] as images.
