If you want a low noise microphone preamplifier, try the Analog Device SSM2019. This chip, characterized by excellent noise performances, low THD and wide bandwidth, is easy to use because of the small number of external components required. The schematic diagram that appears below was inspired by the A.D SSM2019 technical note.
May 2011 update : I recently needed a low noise, higher gain instrumentation amplifier for measurement purpose : I merely added a switch inserting a 12 ohms resistor in parallel with the 100 ohms. Thus the available gain is now 10 or 930 according to the switch setting.
