Another Mono Audio Mixer

http://www.musicfromouterspace.com/

This mixer shows you how to make microphone pre-amps for low and hi impedance mics. Use the lowest noise op-amp you can find that has similar characteristics to the LT1112 (although it is not too shabby itself). The board has extra line inputs and follows the schematic.

Another Mono Audio Mixer Circuit Schematic

Another Mono Audio Mixer PC Board Component Side Shown

Another Mono Audio Mixer PC Board Parts Layout